Geir Johnsen

Om

Geir Johnsen is a professor in marine biology at the Department of Biology (NTNU at Trondhjem biological station, TBS), Prof II at University Centre on Svalbard (UNIS), and is one of the founding partners in a NTNU spin-off company Ecotone using new optical techniques for mapping and monitoring the marine environment. He is a key scientist in the Centre of excellence (CeO) "Autonomous Marine Operations and Systems (AMOS) using enabling technology for marine ecological studies.

He has been at 1 years research stays at University of California at Santa Barbara (1992-93) , Curtin University, Perth, Australia (2010-11) and University of Hawaii at Manoa, Honolulu (2018-19).

Adviser for 48 MSc and 17 PhD students graduated. Currently he advises 7 PhD candidates and 2 post docs. He have published >140 papers in international scientific journals and been a co-editor for the books "Ecosystem Barents Sea" (Tapir Academic Press, 2009), Phytoplankton pigments: Updates on Characterization, Chemotaxonomy and Applications in Oceanography (Cambridge University Press, 2011) and “Life and Light in the Dead of Night” (Springer-Nature, published end of March 2020).

Research areas

Marine ecology and biodiversity in temperate, tropical and arctic regions
Bio-optics
Photosynthesis and eco-physiology in phytoplankton, ice algae and macroalgae
Pigment chemotaxonomy, light harvesting and photo-protective function
Underwater robotics and sensor development for in situ identification of organisms
Mapping and monitoring of bio-geo-chemical objects of interest in the marine environment
Polar night marine ecology
Photo-biology - Light as a cue of light

Publikasjoner

2023

Williamson, David Roddan; Moreira Fragoso, Glaucia; Majaneva, Sanna Kristiina; Dallolio, Alberto; Halvorsen, Daniel Ørnes; Hasler, Oliver Kevin. (2023) Monitoring Algal Blooms with Complementary Sensors on Multiple Spatial and Temporal Scales. Oceanography
Vitenskapelig artikkel
Bakken, Sivert; Henriksen, Marie Bøe; Birkeland, Roger; Langer, Dennis David; Oudijk, Adriënne Esmeralda; Berg, Simen. (2023) HYPSO-1 CubeSat: First Images and In-Orbit Characterization. Remote Sensing
Vitenskapelig artikkel
Summers, Natalie Maria; Moreira Fragoso, Glaucia; Johnsen, Geir. (2023) Photophysiologically active green, red, and brown macroalgae living in the Arctic Polar Night. Scientific Reports
Vitenskapelig artikkel
Grant, Stephen Denis; Johnsen, Geir; McKee, David; Zolich, Artur Piotr; Cohen, Jonathan H.. (2023) Spectral and RGB analysis of the light climate and its ecological impacts using an all-sky camera system in the Arctic. Applied Optics
Vitenskapelig artikkel
Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte; Chierici, Melissa. (2023) Still Arctic? — The changing Barents Sea. Elementa: Science of the Anthropocene
Vitenskapelig oversiktsartikkel/review
Schartmuller, Bernhard; Anderson, Philip; Mckee, David; Connan-McGinty, Stacey; Kopec, Tomasz Piotr; Daase, Malin Hildegard Elisabeth. (2023) Development and calibration of a high dynamic range and autonomous ocean-light instrument to measure sub-surface profiles in ice-covered waters. Applied Optics
Vitenskapelig artikkel

2022

Nøland, Annecken; Johnsen, Geir; Aberle-Malzahn, Nicole. (2022) Autonomous Underwater Vehicle (AUV) based study of zooplankton communities, using a silhouette camera and artificial intelligence. NTNU
Mastergradsoppgave
Johnsen, Geir; Aberle-Malzahn, Nicole; Fragoso, Glaucia; Thu, Maren. (2022) Phytoplankton Spring Bloom Mapping in Coastal Areas Using Autonomous Underwater Vehicle (AUV) and Optical Approaches. NTNU
Mastergradsoppgave
Zolich, Artur Piotr; Faltynkova, Andrea; Johnsen, Geir; Johansen, Tor Arne. (2022) Portable Catamaran Drone - an uncrewed sampling vehicle for micro-plastics and aquaculture research.
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Summers, Natalie; Johnsen, Geir; Mogstad, Aksel Alstad; Løvås, Håvard; Fragoso, Glaucia Moreira; Berge, Jørgen. (2022) Underwater Hyperspectral Imaging of Arctic Macroalgal Habitats during the Polar Night Using a Novel Mini-ROV-UHI Portable System. Remote Sensing
Vitenskapelig artikkel
Fragoso, Glaucia Moreira; Davies, Emlyn John; Fossum, Trygve Olav; Ullgren, Jenny; Majaneva, Sanna; Aberle-Malzahn, Nicole. (2022) Contrasting phytoplankton-zooplankton distributions observed through autonomous platforms, in-situ optical sensors and discrete sampling. PLOS ONE
Vitenskapelig artikkel
Mogstad, Aksel Alstad; Løvås, Håvard; Sture, Øystein; Johnsen, Geir; Ludvigsen, Martin. (2022) Remote Sensing of the Tautra Ridge: An Overview of the World’s Shallowest Cold-Water Coral Reefs. Frontiers in Marine Science
Vitenskapelig artikkel
Nevstad, Malin Bø; Johnsen, Geir; Bakken, Torkild; Larsen, Martin Kvisvik; Mogstad, Aksel Alstad. (2022) Use of different imaging systems for ROV-based mapping of complex benthic habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Marnor, Camilla Mult; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Mapping distribution patterns of brittle stars using ROV-based imaging. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Bjerkvoll, Mikkel; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Aerial and underwater hyperspectral imagery for shallow benthic nature type mapping. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Søreng, Marte Opsahl; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad; Gryte, Kristoffer. (2022) Mapping of Zostera Habitat in the Sublittoral Zone using Underwater Hyperspectral Imaging and Unmanned Surface Vehicle. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Connan-McGinty, Stacey; Banas, Neil S.; Berge, Jørgen; Cottier, Finlo Robert; Grant, Stephen; Johnsen, Geir. (2022) Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea. Journal of Advances in Modeling Earth Systems
Vitenskapelig artikkel
Oudijk, Esmée; Hasler, Oliver Kevin; Øveraas, Henning; Marty, Sabine; Williamson, David Roddan; Svendsen, Torbjørn Karl. (2022) Campaign For Hyperspectral Data Validation In North Atlantic Coastal Waters. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Vitenskapelig artikkel
Dona, Angela; Evertsen, Jussi; Johnsen, Geir. (2022) The role of parapodia and lack of photoacclimation in kleptoplasts of the sacoglossan sea slug Plakobranchus ocellatus. Coral reefs
Vitenskapelig artikkel

2021

Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura. (2021) Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night. PLoS Biology
Vitenskapelig artikkel
Cardwell, CR; Berge, Jørgen; Johnsen, Geir. (2021) Arctic voyage shines light on some cold, hard truths. The Herald, UK
Populærvitenskapelig artikkel
Bazilchuk, Nancy Reney; Berge, Jørgen; Johnsen, Geir. (2021) Lysforurensning I Arktis kan ha ødelagt forskningsresultater. Gemini.no
Populærvitenskapelig artikkel
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2019) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer.
Annet produkt
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2018) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer. .
Annet produkt
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2019) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
Annet produkt
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2020) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
Annet produkt
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2017).
Annet produkt
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2018) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
Annet produkt
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2020) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
Annet produkt
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2019) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
Annet produkt
Ringvold, Halldis; Taite, Morag; Allcock, A. Louise; Vecchione, Michael; Péan, Michel; Sandulli, Roberto. (2021) In situ recordings of large gelatinous spheres from NE Atlantic, and the first genetic confirmation of egg mass of Illex coindetii (Vérany, 1839) (Cephalopoda, Mollusca). Scientific Reports
Vitenskapelig artikkel
Bakken, Sivert; Johnsen, Geir; Johansen, Tor Arne. (2021) Analysis and Model Development of Direct Hyperspectral Chlorophyll-A Estimation for Remote Sensing Satellites. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Vitenskapelig artikkel
Horni, K; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin. (2021) Internasjonalt forskningsmiljø dykker i Mjøsa etter at Oppland Arbeiderblad skrev om forurensning. Oppland arbeiderblad
Populærvitenskapelig artikkel
Bazilchuk, Nancy Reney; Stahl, Annette; Johnsen, Geir; Saad, Aya; Thu, Maren; Nøland, Annecken. (2021) Sporhunden som lukter mikroalger. . Gemini.no
Populærvitenskapelig artikkel
Ringvold, Halldis; Johnsen, Geir; Andersen, Tom. (2021) Studies on Echinodermata from the NE Atlantic Ocean - Spatial distribution and abundance of Asteroidea, including taxonomic and molecular studies on Crossaster and Henricia genera - Value-chain results, including test fishery, biology, market and nutritional analysis on Parastichopus tremulus (Holothuroidea) from the Norwegian coast. Doktoravhandlinger ved NTNU (2021-254)
Doktorgradsavhandling
Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2021) Underwater hyperspectral imaging as a tool for benthic habitat mapping. Doktoravhandlinger ved NTNU (2021/271)
Doktorgradsavhandling
Snyder, Mike; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2021) “Into the dark” documentary by Mike Snyder following Jørgen Berge (UiT), Geir Johnsen (NTNU) and David McKee (Uni Strathclyde) during Polar Night marine ecology work. .
Film
Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan H.; Mckee, David. (2021) All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic. Applied Optics
Vitenskapelig artikkel
Geoffroy, Maxime; Langbehn, Tom Jasper; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault. (2021) Pelagic organisms avoid white, blue, and red artificial light from scientific instruments. Scientific Reports
Vitenskapelig artikkel
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2019).
Annet produkt
Løvås, Håvard; Mogstad, Aksel Alstad; Sørensen, Asgeir Johan; Johnsen, Geir. (2021) A Methodology for Consistent Georegistration in Underwater Hyperspectral Imaging. IEEE Journal of Oceanic Engineering
Vitenskapelig artikkel
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2018).
Annet produkt
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2020).
Annet produkt
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2017) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) .
Annet produkt
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Photosynthetic active radiation (PAR) time series measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
Annet produkt
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2017) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer.
Annet produkt
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2020) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer.
Annet produkt
Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2018) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
Annet produkt
Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2017) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
Annet produkt
Faltynkova, Andrea; Johnsen, Geir; Wagner, Martin. (2021) Hyperspectral imaging as an emerging tool to analyze microplastics: A systematic review and recommendations for future development. Microplastics and Nanoplastics
Vitenskapelig oversiktsartikkel/review

2020

Ramirez-Llodra, Eva; Hilário, Ana; Paulsen, Emil; Costa, Carolina; Bakken, Torkild; Johnsen, Geir. (2020) Benthic Communities on the Mohn’s Treasure Mound: Implications for Management of Seabed Mining in the Arctic Mid-Ocean Ridge. Frontiers in Marine Science
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir. (2020) Life and Light at the Dead of Night. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Johnsen, Geir; Zolich, Artur Piotr. (2020) Light in the Polar Night. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H.. (2020) Operative Habitat Mapping and Monitoring in the Polar Night. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Berge, Jørgen; Johnsen, Geir. (2020) • Polar Night Exhibitions in Russia 2020. Kaliningrad – World Ocean Museum.
Museumsutstilling
Gibbens, Sarah; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2020) As the Arctic warms, light pollution may pose a new treat to marine life. . National Geographic
Intervju tidsskrift
Johnsen, Geir; Leu, Eva; Gradinger, Rolf. (2020) Marine Micro- and Macroalgae in the Polar Night. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.. (2020) Artificial light during the polar night disrupts Arctic fish and zooplankton behavior down to 200 m depth. Communications Biology
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Polar night marine ecology - life and light in the dead of night. Springer Advances in Polar Ecology (0)
Vitenskapelig antologi/Konferanseserie
Berge, Jørgen; Johnsen, Geir. (2020) Polar Night exhibition in Karelia (Petrozavodsk, Russia): 03.03 – 03.04.2020 . Polar Night exhibition, Karelia (Petrozavodsk, Russia). March-April 2020
Museumsutstilling
Saad, Aya; Stahl, Annette; Våge, Andreas; Davies, Emlyn John; Nordam, Tor; Aberle-Malzahn, Nicole. (2020) Advancing Ocean Observation with an AI-driven Mobile Robotic Explorer. Oceanography
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Introduction. Springer
Innledning
Fragoso, Glaucia Moreira; Johnsen, Geir; Chauton, Matilde Skogen; Cottier, Finlo Robert; Ellingsen, Ingrid H.. (2020) Phytoplankton community succession and dynamics using optical approaches. Continental Shelf Research
Vitenskapelig artikkel
Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan. (2020) Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots. Remote Sensing
Vitenskapelig artikkel

2019

Fragoso, Glaucia Moreira; Davies, Emlyn John; Ellingsen, Ingrid H.; Chauton, Matilde Skogen; Fossum, Trygve Olav; Ludvigsen, Martin. (2019) Physical controls on phytoplankton size structure, photophysiology and suspended particles in a Norwegian biological hotspot. Progress in Oceanography
Vitenskapelig artikkel
Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2019) Sea surface microlayer and elemental composition in phaeo-, chloro-, and rhodophytes in winter and spring. Journal of Phycology
Vitenskapelig artikkel
Graham, Lisa Kristine Hernandez; Johnsen, Geir; Christensen-Dalsgaard, Signe. (2019) A pilot study assessing drones for mapping and monitoring of European shags. Institutt for biologi, NTNU
Mastergradsoppgave
Mogstad, Aksel Alstad; Johnsen, Geir; Ludvigsen, Martin. (2019) Shallow-Water Habitat Mapping using Underwater Hyperspectral Imaging from an Unmanned Surface Vehicle: A Pilot Study. Remote Sensing
Vitenskapelig artikkel
Kauko, Hanna Maria; Pavlov, Alexey; Johnsen, Geir; Granskog, Mats; Peeken, Ilka; Assmy, Philipp. (2019) Photoacclimation state of an Arctic underice phytoplankton bloom. Journal of Geophysical Research (JGR): Oceans
Vitenskapelig artikkel
Pavlov, Alexey K.; Leu, Eva; Hanelt, Dieter; Bartsch, Inka; Karsten, Ulf; Hudson, Stephen. (2019) The Underwater Light Climate in Kongsfjorden and Its Ecological Implications. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Bazilchuk, Nancy Reney; Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Ludvigsen, Martin; Johnsen, Geir. (2019) Smart undervannsrobot leter etter plankton. Av N Bazilchuk. Forskning.no. Angående NTNU Entice prosjekt publisert i Science Robotics. Forskning.no
Populærvitenskapelig artikkel
Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Davies, Emlyn John; Ullgren, Jenny; Mendes, Renato; Johnsen, Geir. (2019) Toward adaptive robotic sampling of phytoplankton in the coastal ocean. Science robotics
Vitenskapelig artikkel
Fragoso, Glaucia Moreira; Poulton, Alex James; Pratt, Nicola Jane; Johnsen, Geir; Purdie, Duncan Alastair. (2019) Trait-based analysis of subpolar North Atlantic phytoplankton and plastidic ciliate communities using automated flow cytometer. Limnology and Oceanography
Vitenskapelig artikkel

2018

Fragoso, Glaucia Moreira; Poulton, Alex J.; Yashayaev, Igor M.; Head, Erica J.H.; Johnsen, Geir; Purdie, Duncan A.. (2018) Diatom biogeography from the Labrador Sea revealed through a trait-based approach. Frontiers in Marine Science
Vitenskapelig artikkel
Dumke, Ines; Nornes, Stein Melvær; Purser, Autun; Marcon, Yann; Ludvigsen, Martin; Ellefmo, Steinar Løve. (2018) First hyperspectral imaging survey of the deep seafloor: High-resolution mapping of manganese nodules. Remote Sensing of Environment
Vitenskapelig artikkel
Zolich, Artur Piotr; De La Torre, Pedro R.; Rodwell, Shane; Geoffroy, Maxime; Johnsen, Geir; Berge, Jørgen. (2018) An ice-tethered buoy for fish and plankton research. IEEE conference proceedings
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Fjærtoft, Kaja Lønne; Bakken, Torkild; Johnsen, Geir; Ludvigsen, Martin. (2018) Macroalgal detritus: Physical variables and impacts on the benthic macrofaunal community. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin; Hansen, Roy Edgar; Maarleveld, Thijs. (2018) Towards Autonomous Operations and Systems in Marine Archaeology. Doktoravhandlinger ved NTNU (IMT-12)
Doktorgradsavhandling
Strømsholm, Jørgen; Johnsen, Geir; Ludvigsen, Martin. (2018) Eyes beneath the surface - using a miniROV to reveal habitat and dietary choices of the European shag. NTNU MSc thesis
Mastergradsoppgave
Kauko, Hanna Maria; Johnsen, Geir; Assmy, Phillipp. (2018) Light response and acclimation of macroalgae in a changing Arctic. Doktoravhandlinger ved NTNU (2018)
Doktorgradsavhandling
Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning - enda en kilde til bekymring. Svalbardposten
Kronikk
Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning truer livet i Arktis. Aftenposten Viten
Kronikk
Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; De La Torre, Pedro R.; Nornes, Stein Melvær. (2018) Use of an autonomous surface vehicle reveals small-scale diel vertical migrations of zooplankton and susceptibility to light pollution under low solar irradiance. Science Advances
Vitenskapelig artikkel
Nornes, Stein Melvær; Sørensen, Asgeir Johan; Ludvigsen, Martin; Johnsen, Geir; Schjølberg, Ingrid; Ånonsen, Kjetil Bergh. (2018) Guidance and Control of Marine Robotics for Ocean Mapping and Monitoring. Doktoravhandlinger ved NTNU (2018:202)
Doktorgradsavhandling
Ødegård, Øyvind; Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging: a new tool for marine archaeology. Applied Optics
Vitenskapelig artikkel
Fossum, Trygve Olav; Eidsvik, Jo; Ellingsen, Ingrid H.; Alver, Morten; Fragoso, Glaucia Moreira; Johnsen, Geir. (2018) Information-driven robotic sampling in the coastal ocean. Journal of Field Robotics (JFR)
Vitenskapelig artikkel
Kauko, Hanna Maria; Olsen, Lasse Mork; Duarte, Pedro; Peeken, Ilka; Granskog, Mats A.; Johnsen, Geir. (2018) Algal colonization of young arctic sea ice in spring. Frontiers in Marine Science
Vitenskapelig artikkel
Dumke, Ines; Purser, Autun; Marcon, Yann; Nornes, Stein Melvær; Johnsen, Geir; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging as an in situ taxonomic tool for deep-sea megafauna. Scientific Reports
Vitenskapelig artikkel
Liefmann, Stephanie; Järnegren, Johanna; Johnsen, Geir; Murray, Fiona. (2018) Eco-physiological responses of cold-water soft corals to anthropogenic sedimentation and particle shape. Journal of Experimental Marine Biology and Ecology
Vitenskapelig artikkel
Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Langbehn, Tom; Cottier, Finlo Robert. (2018) Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic. Polar Biology
Short communication
Johnsen, Geir; Norli, Marit; Moline, Mark A.; Robbins, Ian; Quillfeldt, Cecilie von; Sørensen, Kai. (2018) The advective origin of an under-ice spring bloom in the Arctic Ocean using multiple observational platforms. Polar Biology
Vitenskapelig artikkel
Dumke, Ines; Ludvigsen, Martin; Ellefmo, Steinar Løve; Søreide, Fredrik; Johnsen, Geir; Murton, Bramley J.. (2018) Underwater Hyperspectral Imaging Using a Stationary Platform in the Trans-Atlantic Geotraverse Hydrothermal Field. IEEE Transactions on Geoscience and Remote Sensing
Vitenskapelig artikkel
Gabrielsen, Tove M.; Johnsen, Geir. (2018) Skogen på Svalbard. Svalbardposten
Populærvitenskapelig artikkel

2017

Berge, Jørgen; Johnsen, Geir; Tandberg, Anne helene. (2017) Polar night - Life and light in the dead of night. Russian Science Week - Lomonosov Moscow State University
Museumsutstilling
Otterlei, Inger; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin; Hareide, Nils Roar; Christensen-Dalsgaard, Signe. (2017) 300 000 sjøfugl er forsvunnet fra Runde. Sunnmørsposten
Intervju tidsskrift
Mynors, Julie; Johnsen, Geir; Wernand, Marcel; Volent, Zsolt. (2017) Ocean Colour and Phytoplankton Dynamics - An examination of the Forel-Ule scale in a modern context. NTNU Trondheim
Mastergradsoppgave
Johnsen, Geir; Christiansen, Hanne H; Ravolainen, Virve; Reymert, Per Kyrre; Jenssen, Eva Therese; Arlov, Thor Bjørn. (2017) Utfordrende natur og sikkerhet på Svalbard. Svalbardposten
Kronikk
Kamilla, Sporsheim; Sporsheim, Kamilla; Johnsen, Geir; Reitan, Kjell Inge; Evertsen, Antii Jussi. (2017) Astaxanthin as a biomarker for fish feed loading in the marine ecosystem. NTNU, Trondheim
Mastergradsoppgave
Kjeken, John; Johnsen, Geir; Ludvigsen, Martin; Thorsnes, Terje; Lågstad, Petter Arthur. (2017) The growth of benthic organisms in a dumping ground for military bombs and munitions. NTNU, Trondheim
Mastergradsoppgave
Johnsen, Geir; Sandbu, Marthe; Assmy, Philipp. (2017) High Arctic Sea-Ice Algae: The Use of Rapid Light Curves to Assess Photosynthetic Performance of Different Ice-Algal Communities. Master science NTNU
Mastergradsoppgave
Ostaszewska, Kaja; Balazy, Piotr; Berge, Jørgen; Johnsen, Geir; Staven, Robert. (2017) Seabirds during Arctic Polar Night: underwater observations from Svalbard archipelago, Norway. Waterbirds (De Leon Springs, Fla.)
Vitenskapelig artikkel
Kauko, Hanna Maria; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C.J.; Duarte, Pedro. (2017) Windows in Arctic sea ice: light transmission and ice algae in a refrozen lead. Journal of Geophysical Research (JGR): Biogeosciences
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir. (2017) Kunnskapshull om livet i Arktis i mørketiden. Aftenposten Viten
Kronikk
Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher John. (2017) Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic. Scientific Reports
Vitenskapelig artikkel
Mogstad, Aksel Alstad; Johnsen, Geir. (2017) Spectral characteristics of coralline algae: a multi-instrumental approach, with emphasis on underwater hyperspectral imaging. Applied Optics
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir. (2017) Om bambus, spøkelseskreps og et Arktis i endring. Svalbardposten
Kronikk
Berge, Jørgen; Johnsen, Geir. (2017) Superkommunisten. Svalbardposten
Kronikk
Andersson, Ingvild Henriette Kristin; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin. (2017) Bio-optical diversity on cold water coral habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Alvsvåg, Dora Marie; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Berge, Jørgen. (2017) Mapping of a seagrass habitat in Hopavågen, Sør-Trøndelag, with the use of an Autonomous Surface Vehicle combined with optical techniques. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Paulsen, Emil; Bakken, Torkild; Ramirez-Llodra, Eva; Johnsen, Geir. (2017) Community structure and biodiversity of the benthic megafauna at the inactive hydrothermal site Mohn's Treasure, on the Mohn's Ridge, Arctic Mid-Ocean Ridge (AMOR) . Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave

2016

Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) Opp fra polarnattens mørke. Aftenposten Viten
Kronikk
Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) A bitter-sweet symphony. Svalbardposten
Kronikk
Gätzschmann, Per; Hårsaker, Karstein; Johnsen, Geir; Leite, Stein Roar; Pedersen, Solbjørg; Sørumgård, Marit. (2016) Nye oppdagelser i polarnatta - video. Polarnatt
Museumsutstilling
Berge, Jørgen; Geoffroy, Maxime; Johnsen, Geir; Cottier, Finlo Robert; Bluhm, Bodil; Vogedes, Daniel Ludwig. (2016) Ice-tethered observational platforms in the Arctic Ocean pack ice. IFAC-PapersOnLine
Vitenskapelig artikkel
Cronin, Heather; Cohen, Jonathan H.; Berge, Jørgen; Johnsen, Geir; Moline, Mark A.. (2016) Bioluminescence as an ecological factor during high Arctic polar night. Scientific Reports
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Ludvigsen, Martin; Cohen, Jonathan. (2016) Design for latskap - men med store muligheter. Svalbardposten
Kronikk
Jakobsen, June; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Karlsen, Svein. (2016) The Tautra Cold-Water Coral Reef - Mapping and describing the biodiversity of a cold-water coral reef ecosystem in the Trondheimsfjord by use of multi-beam echo sounding and video mounted on a remotely operated vehicle. NTNU
Mastergradsoppgave
Bondø, Tor-Hartvig; Johnsen, Geir; Berge, Jørgen. (2016) Fant yrende liv i polarnatta. VG : Verdens gang
Populærvitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir. (2016) Mørkets fyrster med påskrudd lys. Svalbardposten
Populærvitenskapelig artikkel
Bazilchuk, Nancy Reney; Leite, Stein Roar; Johnsen, Geir; Kjeken, John; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2016) Bomber og buss på havbunnen. Gemini
Populærvitenskapelig artikkel
Haudemann-Andersen, Jørn; Lystad, M S; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2016) Blå lys i det kalde dyp. NRK Trøndelag, Nyheter
Populærvitenskapelig artikkel
Haugstad, Tor; Erdal, Ivar; Johnsen, Geir; Sørensen, Asgeir Johan; Fjærvik, Nils. (2016) Gründerne mener dette kameraet kan bli det nye ekkoloddet – Ecotone er kandidat til TU Tech Award. Teknisk Ukeblad
Populærvitenskapelig artikkel
Bjørgan, Espen Halvorsen; Johnsen, Geir; Kjeken, Jon; Ludvigsen, Martin. (2016) Fant buss på 600 m dybde. Adresseavisen
Populærvitenskapelig artikkel
Håpnes, Sverre Julian; Johnsen, Geir; Ludvigsen, Martin; Lågstad, Petter Arthur. (2016) Mapping of demersal fish and benthos by AUV equipped with optical and acoustic imagers at 600 m depth in Trondheimsfjorden. NTNU MSc
Mastergradsoppgave
Liefmann, Stephanie; Johnsen, Geir; Järnegren, Johanna. (2016) Eco-physiological responses of cold-water corals to anthropogenic sedimentation and particle shape. NTNU Mastergrad
Mastergradsoppgave
Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Sørumgård, Marit; Sandbakk, Elin; Johnsen, Tobias Kvendseth. (2016) Polarnatt/Polar Night - ny utstilling med nyheter fra 2015-2016. Polarnattsutstilling ved Vitenskapsmuseet NTNU
Museumsutstilling
Johnsen, Geir; Ludvigsen, Martin; Sørensen, Asgeir Johan; Aas, Lars Martin Sandvik. (2016) The use of underwater hyperspectral imaging deployed on remotely operated vehicle – methods and applications. IFAC-PapersOnLine
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Kinderegg i polarnatten. Svalbardposten
Kronikk
Donahue, Michelle; Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) The age of humans - living in the anthropocene - "Termites of the sea" found munching wood near Arctic shipwrecks. Smithsonian
Populærvitenskapelig artikkel
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Dark lords, werewolves and Indiana Jones in the polar night. Gemini (English edition)
Intervju tidsskrift
Krüger, Frida Jørstad; Johnsen, Geir; Kjeken, John; Ludvigsen, Martin. (2016) Gammel buss ble korallrev. NRK Viten
Populærvitenskapelig artikkel
Kokkegård, Hanne; Johnsen, Geir; Ludvigsen, Martin; Torre, Pedro De La. (2016) Vitenskab - Bomber fra 2 verdenskrig danner koralrev på 600 m dybde. Danmarks radio
Populærvitenskapelig artikkel
Haugstad, Tormod; Erdal, Ivar; Johnsen, Geir. (2016) Kameraet deres «kan bli det nye ekkoloddet». Nå er det norske selskapet i ferd med å lykkes. Teknisk Ukeblad
Intervju tidsskrift
Johnsen, Geir. (2016) Yrende liv i Isfjorden. Svalbardposten
Populærvitenskapelig artikkel
Aarskog, Karine Nigar; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2016) Et stort løft for arktisk forskning (NTNU & UiT). Universitetet i Tromsø
Fagartikkel
Berge, Jørgen; Falk-Petersen, Stig; Renaud, Paul E.; Daase, Malin; Geoffroy, Maxime; Johnsen, Geir. (2016) En reise mot Ultima Thule. Svalbardposten
Populærvitenskapelig artikkel
Lervik, Frank; Johnsen, Geir; Ludvigsen, Martin; Kjeken, John. (2016) Det ligger flere busser der. Adresseavisen
Populærvitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Mark spiser opp vrak på havbunnen. Fiskaren
Populærvitenskapelig artikkel
Kintisch, Eli; Berge, Jørgen; Last, Kim; Cohen, Jonathan; Johnsen, Geir. (2016) Voyage into darkness . Science
Intervju tidsskrift
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Ludvigsen, Martin; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Mørkets fyrster, varulver og Indiana Jones. Gemini
Populærvitenskapelig artikkel
Berge, Jørgen; Renaud, Paul E.; Johnsen, Geir; Darnis, Gerald; Geoffroy, Maxime; Daase, Malin. (2016) I grenselandet (mellom Tull og Thule). Svalbardposten
Populærvitenskapelig artikkel
Førde, Henny; Forbord, Silje; Handå, Aleksander; Fossberg, Julia; Arff, Johanne; Johnsen, Geir. (2016) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. Journal of Applied Phycology
Vitenskapelig artikkel

2015

Nilssen, Ingunn; Dos Santos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral, Marcelo M.; Eide, Ingvar. (2015) Assessing the potential impact of water-based drill cuttings on deep water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
Vitenskapelig artikkel
Nilssen, Ingunn; Santos dos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral Montenegro, Marcelo; Eide, Ingvar. (2015) Assessing the potential impact of water-based drill cuttings on deep-water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan; Nilssen, Ingunn. (2015) Enabling technology for Arctic research. Pan European Networks: Science and Techology Magazine
Vitenskapelig oversiktsartikkel/review
Rodriguez, Francisco; Garrido, J.L.; Sabrino, C; Johnsen, Geir; Riobo, P; Franco, J. (2015) Divinyl chlorophyll a in the marine eukaryotic protist Alexandrium ostenfeldii (Dinophyceae). Environmental Microbiology
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) Life and light in the dead of night. Museumsutstilling
Museumsutstilling
Nilssen, Ingunn; Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Moline, Mark A.; Berge, Jørgen. (2015) Integrated environmental mapping and monitoring, a methodological approach to optimise knowledge gathering and sampling strategy. Marine Pollution Bulletin
Vitenskapelig artikkel
Aarekol, Lena; Johnsen, Geir; Berge, Jørgen. (2015) Polarnatt. Liv og lys i mulm og mørke Polarnighth. Life and death in dead of night. Utstilling
Museumsutstilling
Ludvigsen, Martin; Thorsnes, Terje; Hansen, Roy Edgar; Sørensen, Asgeir Johan; Johnsen, Geir; Lågstad, Petter Arthur. (2015) Underwater vehicles for environmental management in coastal areas. IEEE conference proceedings
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Tandberg, Anne Helene S.; Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) POLARNATT - liv og lyst i mulm og mørke. Polarnatt - liv og lyst i mulm og mørke
Museumsutstilling
Berge, Jørgen; Johnsen, Geir. (2015) Polarnatt - Liv og lys i mulm og mørke Polar night - life and light in the dead of night. Utstilling på Polarmuseet i Tromsø
Museumsutstilling
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig. (2015) Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton?. PLOS ONE
Vitenskapelig artikkel
Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.. (2015) In the dark: a review of ecosystem processes during the Arctic polar night. Progress in Oceanography
Vitenskapelig artikkel
Berge, Jørgen; Daase, Malin; Renaud, Paul; Ambrose, William G. Jr.; Darnis, Gérald; Last, Kim S. (2015) Unexpected levels of biological activity during the polar night offer new perspectives on a warming Arctic. Current Biology
Vitenskapelig artikkel

2014

Pettersen, Ragnhild; Johnsen, Geir; Bruheim, Per; Andreassen, Trygve. (2014) Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organisms. Organisms Diversity & Evolution
Vitenskapelig artikkel
Valle, Kristin Collier; Nymark, Marianne; Aamot, Inga; Hancke, Kasper; Winge, Per; Andresen, Kjersti. (2014) System responses to equal doses of photosynthetically usable radiation of blue, green, and red light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
Vitenskapelig artikkel
Lund, Lene; Johnsen, Geir; Bakken, Torkild; Gabrielsen, Tove. (2014) Morphological diversity in Laminaria digitata - different species or different phenotypes?. Norwegian University of Science and Technology, Department of Biology
Mastergradsoppgave
Valle, Kristin Collier; Johnsen, Geir; Bones, Atle M. (2014) Photoacclimation mechanisms and light responses in marine micro- and macroalgae. NTNU
Doktorgradsavhandling
Hallerud, Charlotte; Johnsen, Geir; Aamot, Inga. (2014) Pigment composition of macroalgae from a Norwegian kelp forest. NTNU
Mastergradsoppgave
Kjerstad, Ingrid; Johnsen, Geir; Sørensen, Asgeir Johan; Bakken, Torkild. (2014) Underwater Imaging and the effect of Inherent Optical Properties on image quality. NTNU
Mastergradsoppgave
Førde, Henny; Reitan, Kjell Inge; Johnsen, Geir. (2014) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. NTNU
Mastergradsoppgave
Hatlebakk, Maja; Johnsen, Geir; Søreide, Janne. (2014) Effect of lipids and fatty acid composition on success of reproduction in Calanus glacialis. NTNU
Mastergradsoppgave
Ødegård, Øyvind; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan; Dukan, Fredrik. (2014) Managing data from multiple sensors in an interdisciplinary research cruise. Amsterdam University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2014) Elemental composition in various marine brown, green and red macro algae with respect to season and tissue age. NTNU
Mastergradsoppgave
Kvernvik, Ane Cecilie; Johnsen, Geir; Aamot, Inga. (2014) How lamina age influence photosynthetic response to light variations in Saccharina latissima. NTNU
Mastergradsoppgave
Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Lågstad, Petter Arthur; Ødegård, Øyvind. (2014) Scientific Operations Combining ROV and AUV in the Trondheim Fjord. Marine Technology Society journal
Vitenskapelig artikkel
Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Glowing in the dark: Discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
Vitenskapelig artikkel
Hansen, Ingrid; Pettersen, Ragnhild; Beuchel, Frank; Cochrane, Sabine; Frantzen, marianne; Ekehaug, Stefan. (2014) Underwater hyperspectral imaging (UHI) for environmental mapping and monitoring of seabed habitats. Ocean Optics
Sammendrag/abstract
Cohen, Jonathan; Cronin, Heather; Moline, Mark A.; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Are krill eyes useful in the high Arctic polar night?. Ocean Optics
Sammendrag/abstract
Johnsen, Geir; Ekehaug, Stefan; Hansen, Ingrid; Sørensen, Asgeir Johan. (2014) The use of underwater hyperspectral imaging deployed on remotely operated vehicles to identify, map and monitor bio-geo-chemical objects of interest. Ocean Optics
Sammendrag/abstract
Aamot, Inga; Pokrzywinski, Kaytee; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan. (2014) Light Climate and Status of the Photosynthetic Machinery in Macroalgae in the Polar Night. Ocean Optics
Sammendrag/abstract
Nornes, Stein Melvær; Candeloro, Mauro; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Photomosaic camera as simultaneous data collector and navigation aid on unmanned underwater vehicles. Ocean Optics
Sammendrag/abstract
Nilssen, Ingunn; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen; Nornes, Stein Melvær. (2014) Integrated environmental monitoring; a methodological approach to optimise knowledge gathering and sampling strategy. Ocean Optics
Sammendrag/abstract
Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Valle, Kristin Collier. (2014) Photoacclimation mechanisms and light responses in marine micro- and macroalgae. Doktoravhandlinger ved NTNU (74)
Doktorgradsavhandling
Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Erratum to: Glowing in the dark: discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
Errata
Berge, Jørgen; Cottier, Finlo; Varpe, Øystein; Renaud, Paul; Falk-Petersen, Stig; Kwasniewski, Sawomir. (2014) Arctic complexity: A case study on diel vertical migration of zooplankton. Journal of Plankton Research
Vitenskapelig artikkel
Eldevik, Tor; Reigstad, Marit; Falck, Eva; Gerland, Sebastian; Jentoft, Sissel; Johnsen, Geir. (2014) Arven efter Nansen. Forskningsplan for det sentrale og nordlige Barentshavet. UiT Norges arktiske universitet UiT Norges arktiske universitet
Rapport
Hancke, Kasper; Hovland, Erlend Kjeldsberg; Volent, Zsolt; Pettersen, Ragnhild; Johnsen, Geir; Moline, Mark A.. (2014) Optical properties of CDOM across the Polar Front in the Barents Sea: Origin, distribution and significance. Journal of Marine Systems
Vitenskapelig artikkel
Hovland, Erlend Kjeldsberg; Hancke, Kasper; Alver, Morten; Drinkwater, Kennneth F.; Høkedal, Jo; Johnsen, Geir. (2014) Optical impact of an Emiliania huxleyi bloom in the frontal region of the Barents Sea. Journal of Marine Systems
Vitenskapelig artikkel

2013

Ingrid, Hansen; Johnsen, Geir; Sørensen, Asgeir Johan. (2013) Optical Mapping of Cold-water Corals in Trondheimsfjorden and Svalbard. NTNU
Mastergradsoppgave
Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan. (2013) The use of side scan and synthetic aperture sonar mounted on autonomous underwater vehicles for biological habitat mapping. MSc Thesis (2013)
Mastergradsoppgave
Båtnes, Anna Solvang; Miljeteig, Cecilie; Berge, Jørgen; Greenacre, Michael; Johnsen, Geir. (2013) Quantifying the light sensitivity of Calanus spp. during the polar night: potential for orchestrated migrations conducted by ambient light from the sun, moon, or aurora borealis. Polar Biology
Vitenskapelig artikkel
Pettersen, Ragnhild; Johnsen, Geir. (2013) Identification of marine organisms using Chemotaxonomy and Hyperspectral imaging. Doktoravhandlinger ved NTNU (292)
Doktorgradsavhandling
Båtnes, Anna Solvang; Johnsen, Geir. (2013) Light in the dark – the role of irradiance in the high Arctic marine ecosystem during polar night. Doktoravhandlinger ved NTNU (151)
Doktorgradsavhandling
Johnsen, Geir; Volent, Zsolt; Dierssen, Heidi; Pettersen, Ragnhild; Ardelan, Murat Van; Søreide, Fredrik. (2013) Underwater hyperspectral imagery to create biogeochemical maps of seafloor properties. Woodhead Publishing Limited
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Ludvigsen, Martin; Johnsen, Geir; Lågstad, Petter Arthur; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2013) Scientific operations combining ROV and AUV in the Trondheim Fjord. IEEE conference proceedings
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Nymark, Marianne. (2013) Light responses in the marine diatom Phaeodactylum tricornutum. Doktoravhandlinger ved NTNU (378)
Doktorgradsavhandling
Berge, Jørgen; Johnsen, Geir; Falk-Pettersen, Stig. (2013) Mørkets hemmeligheter. Svalbardposten
Populærvitenskapelig artikkel
Nymark, Marianne; Valle, Kristin Collier; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir. (2013) Molecular and photosynthetic responses to prolonged darkness and subsequent acclimation to re-illumination in the diatom Phaeodactylum tricornutum. PLOS ONE
Vitenskapelig artikkel
Hovland, Erlend Kjeldsberg; Dierssen, Heidi; Ferreira, Ana Sofia; Johnsen, Geir. (2013) Dynamics regulating major trends in Barents Sea temperatures and subsequent effect on remotely sensed particulate inorganic carbon. Marine Ecology Progress Series
Vitenskapelig artikkel

2012

Bjørdalsbakke, Lise Kristin; Johnsen, Geir; Bakken, Torkild; Berge, Jørgen. (2012) Population structure, parasitism and prey preference in Sclerocrangon boreas and S. ferox, Svalbard. NTNU
Hovedfagsoppgave
Hovland, Erlend Kjeldsberg; Johnsen, Geir; Sakshaug, Egil; Folkestad, Are. (2012) Bio-optics and ecology in Emiliania huxleyi blooms: Field and remote sensing studies in Norwegian water. NTNU
Doktorgradsavhandling
Berge, Jørgen; Båtnes, Anna Solvang; Johnsen, Geir; Blackwell, Susan; Moline, Mark A.. (2012) Bioluminescence in the high Arctic during the polar night. Marine Biology
Vitenskapelig artikkel
Belseth, Elen; Johnsen, Geir; Berge, Jørgen. (2012) Eco-physiology of the Arctic kelp Laminaria solidungula. NTNU Master thesis
Mastergradsoppgave
Fremstedal, Ane Sofia Viset; Bruheim, Per; Sletta, Håvard; Johnsen, Geir. (2012) Utvikling og optimalisering av protokoll for massespektrometrisk metabolsk profilering av adherente humane celler. NTNU Master theses
Mastergradsoppgave
Gabrielsen, Tove M; Quillfeldt, Cecilie von; Johnsen, Geir; Berge, Jørgen. (2012) Varm vinter, sen vår i fjorden. Svalbardposten
Leserinnlegg
Elde, Anette; Pettersen, Ragnhild; Bruheim, Per; Järnegren, Johanna; Johnsen, Geir. (2012) Pigmentation and Spectral Absorbance Signatures in Deep-Water Corals from the Trondheimsfjord, Norway. Marine Drugs
Vitenskapelig artikkel
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2012) Phytoplankton Pigments: Characterization, Chemotaxonomy and Applications in Oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2012)
Vitenskapelig antologi/Konferanseserie

2011

Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2011) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
Vitenskapelig artikkel
Andersen, Hanne Kile; Johnsen, Geir; Bakken, Torkild. (2011) Gastropods Associated with Laminaria hyperborea and Saccorhiza polyschides in a Norwegian Kelp Forest: Comparison of Sampling and In Situ Imaging Techniques. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Brunet, Christophe; Johnsen, Geir; Lavaud, Johan; Roy, Suzanne. (2011) Pigments and photoacclimation processes. Cambridge University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Bricaud, Annick; Nelson, Norman; Prézelin, Barbara; Bidigare, Robert. (2011) In vivo bio-optical properties of phytoplankton pigments. Cambridge University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Volent, Zsolt; Johnsen, Geir; Hovland, Erlend Kjeldsberg; Folkestad, Are; Olsen, Lasse Mork; Tangen, Karl. (2011) Improved monitoring of phytoplankton bloom dynamics in a Norwegian fjord by integrating satellite data, pigment analysis, and Ferrybox data with a coastal observation network. Journal of Applied Remote Sensing
Vitenskapelig artikkel
Johnsen, Geir; Moline, Mark; Pettersson, Lasse H.; Pinckney, J. L.; Pozdnyakov, Dmitry; Egeland, Einar Skarstad. (2011) Optical monitoring of phytoplankton bloom pigment signatures. Cambridge University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Llewellyn, Carole A.; Roy, Suzanne; Johnsen, Geir; Egeland, Einar Skarstad; Chauton, Matilde ; Hallegraeff, Gustaff. (2011) Perspectives on future directions. Cambridge University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Preface. Cambridge University Press
Forord
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Acknowledgements. Cambridge University Press
Annet
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Phytoplankton pigments : characterization, chemotaxonomy and applications in oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2011)
Vitenskapelig antologi/Konferanseserie
Jouenne, Fabien; Eikrem, Wenche; Le Gall, F; Marie, Dominique; Johnsen, Geir; Vaulot, Daniel. (2011) Prasinoderma singularis sp. nov. (Prasinophyceae, Chlorophyta), a Solitary Coccoid Prasinophyte from the South-East Pacific Ocean. Protist
Vitenskapelig artikkel
Pettersen, Ragnhild; Johnsen, Geir; Berge, Jørgen; Hovland, Erlend Kjeldsberg. (2011) Phytoplankton chemotaxonomy in waters around the Svalbard archipelago reveals high amounts of Chl b and presence of gyroxanthin-diester. Polar Biology
Vitenskapelig artikkel

2010

Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2010) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
Vitenskapelig artikkel
Aamot, Inga; Berge, Jørgen; Hancke, Kasper; Johnsen, Geir; Moline, Mark; Schofield, Oscar. (2010) NORUS - Technology Development for Marine Monitoring and Ocean Observation:An North America-Norway educational program. http://ipy-osc.no/abstract/
Sammendrag/abstract
Johnsen, Geir; Søreide, Fredrik. (2010) Underwater hyperspectral imaging of marine mineral deposits. Underwater Mining meeting Institute (UMI)
Sammendrag/abstract

2009

Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit M.. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
Fagbok
Johnsen, Geir; Nepstad, Ina. (2009) Cloning and characterisation of interleukin-6 and interleukin-11b in Atlantic halibut (Hippoglossus hippoglossus). NTNU, Institutt for biologi
Mastergradsoppgave
Elde, Anette Cecilie; Johnsen, Geir. (2009) Pigmentation in deep-water corals from the Trondheimsfjord, Norway. NTNU, Institutt for biologi
Mastergradsoppgave
Thoen, Hanne Halkinrud; Johnsen, Geir. (2009) Pigmentation in the Arctic deep-sea amphipods Eurythenes gryllus and Anonyx sp. NTNU, Institutt for biologi
Mastergradsoppgave
Øye, Ane-Marte; Johnsen, Geir. (2009) Photobioreactor time-series of a simulated bloom of Emiliania huxleyi. NTNU, Institutt for biologi
Mastergradsoppgave
Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
Vitenskapelig antologi/Konferanseserie
Johnsen, Geir; Volent, Z; Sakshaug, E.; Sigernes, Fred; Pettersson, L.H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, E.; Johnsen, Geir; Kristiansen, Svein; Quillfeldt, C.v.; Rey, F.; Slagstad, D.. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, E.; Johnsen, Geir; Volent, Z. (2009) Light. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Quillfeldt, C.v.; Hegseth, E.N.; Johnsen, Geir; Sakshaug, E.; Syvertsen, E.E.. (2009) Ice algae. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
von Quillfeldt, Cecilie H.; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik. (2009) Ice algae. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
von Quillfeldt, Cecilie; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik E.. (2009) Ice algae. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, Egil; Johnsen, Geir; Kristiansen, Svein; von Quillfeldt, Cecilie; Rey, Francisco; Slagstad, Dag. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, Egil; Johnsen, Geir; Volent, Z.. (2009) Light. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Volent, Zsolt; Sakshaug, Egil; Sigernes, Fred; Pettersson, Lasse H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, E.; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
Lærebok
Berge, Jørgen; Cottier, Finlo; Last, Kim S.; Varpe, Øystein; Leu, Eva; Søreide, Janne. (2009) Diel vertical migration of Arctic zooplankton during the polar night. Biology Letters
Vitenskapelig artikkel
Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Winge, Per; Hancke, Kasper; Andresen, Kjersti. (2009) An integrated analysis of molecular acclimation to high light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
Vitenskapelig artikkel
Berge, Jørgen; Lønne, Ole Jørgen; Renaud, Paul; Johnsen, Geir; Gulliksen, Bjørn; Varpe, Øystein. (2009) Polartorsken - vil den bli utkonkurrert av sørlige fiskearter?. Svalbardposten
Populærvitenskapelig artikkel
Evertsen, Jussi; Johnsen, Geir. (2009) In vivo and in vitro differences in chloroplast functionality in the two north Atlantic sacoglossans (Gastropoda, Opisthobranchia) Placida dendritica and Elysia viridis. Marine Biology
Vitenskapelig artikkel
Volent, Z; Johnsen, Geir; Sigernes, Fred. (2009) Microscopic hyperspectral imaging used as a bio-optical taxonomic tool for micro- and macroalgae. Applied Optics
Vitenskapelig artikkel

2008

Båtnes, Anna Solvang; Johnsen, Geir. (2008) Trophic interaction between little auks and their zooplankton prey in a high Arctic fjord based on lipid analyses. NTNU, Institutt for biologi
Mastergradsoppgave
Hancke, Torunn Beate; Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2008) Rate of O2 production derived from pulse-amplitude-modulated fluorescence: Testing three biooptical approaches against measured O2-production rate. Journal of Phycology
Vitenskapelig artikkel
Bredholt, Harald; Fjærvik, Espen; Johnsen, Geir; Zotchev, Sergey. (2008) Actinomycetes from sediments in the Trondheim Fjord, Norway: Diversity and biological activity. Marine Drugs
Vitenskapelig artikkel
Bakken, Torkild; Evertsen, Jussi; Johnsen, Geir. (2008) Vitenskapelig dykking - behov for endringer i forskriften. Dykkenytt : informasjonsorgan for dykkeindustrien
Fagartikkel
Hancke, Kasper; Hancke, Torunn Beate; Olsen, Lasse Mork; Johnsen, Geir; Glud, RN. (2008) Temperature effects on microalgal photosynthesis-light responses measured by O2 production, pulse-amplitude-modulated fluorescence, and C-14 assimilation. Journal of Phycology
Vitenskapelig artikkel
Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark. (2008) Combined use of AUV and hyperspectral imaging to mapping sea-surface and macroalgae. Ocean Optics
Sammendrag/abstract

2007

Kleiven, Mona; Johnsen, Geir. (2007) Pigmentation in Halocynthia pyriformis from Isfjorden, Spitsbergen. NTNU, Institutt for biologi
Mastergradsoppgave
Hovland, Erlend Kjeldsberg; Sakshaug, Egil; Johnsen, Geir. (2007) Tracing Coccolithophorid Blooms in the Barents Sea Using MODIS Level-3 Imagery. NTNU, Institutt for biologi
Mastergradsoppgave
Stübner, Eike; Johnsen, Geir. (2007) Biogeographical distribution of temperate vs. Arctic benthic species around Svalbard. NTNU, Institutt for biologi
Mastergradsoppgave
Pettersen, Ragnhild; Johnsen, Geir. (2007) Phytoplankton systematics and pigmentation in the Arctic. NTNU, Institutt for biologi
Mastergradsoppgave
Hancke, Kasper; Johnsen, Geir. (2007) Photosynthetic responses as a function of light and temperature: Field and laboratory studies on marine microalgae. NTNU, Institutt for biologi
Doktorgradsavhandling
Johnsen, Geir; Volent, Zsolt; Sigernes, F.. (2007) Fine scale studies using hyper-spectral remote sensing. ESSAS Meeting in Marine Arctic Climate
Rapport
Elvestrand, Jostein; Johnsen, Geir; Sneli, Jon-Arne. (2007) Morphometry and patterns of growth in Acesta excavata (Bivalvia: Limidae) from the Trondheimsfjord, Norway. NTNU, Institutt for biologi
Hovedfagsoppgave
Cibic, Tamara; Blasutto, Oriana; Hancke, Kasper; Johnsen, Geir. (2007) Microphytobenthic species composition, pigment concentration, and primary production in sublittoral sediments of the Trondheimsfjord (Norway). Journal of Phycology
Vitenskapelig artikkel
Evertsen, Jussi; Burghardt, Ingo; Johnsen, Geir; Wägele, Heike. (2007) Retention of functional chloroplasts in some sacoglossans from the Indo-Pacific and Mediterranean. Marine Biology
Vitenskapelig artikkel
Ludvigsen, Martin; Sortland, Bjørn; Johnsen, Geir; Singh, Hanumant. (2007) Applications of Geo-Referenced Underwater Photo Mosaics in Marine Biology and Archaeology. Oceanography
Vitenskapelig artikkel
Johnsen, Geir; Sakshaug, Egil. (2007) Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse-amplitude-modulated and fast-repetition-rate fluorometry. Journal of Phycology
Vitenskapelig artikkel
Edvardsen, B; Eikrem, W; Shalchian-Tabrizi, K; Riisberg, I; Johnsen, Geir; Naustvoll, L. (2007) Verrucophora farcimen gen. et sp nov (Dictyochophyceae, Heterokonta) - A bloom-forming ichthyotoxic flagellate from the Skagerrak, Norway. Journal of Phycology
Vitenskapelig artikkel
Johnsen, Geir; Volent, Zsolt; Sigernes, F.; Berge, Jørgen; Hovland, Erlend Kjeldsberg; Sakshaug, Egil. (2007) Local hyperspectral imaging of ocean colour from tethered balloons in the Arctic. In Proceedings from Arctic Frontiers: Balancing human use and ecosystem protection. UiT Norges arktiske universitet UiT Norges arktiske universitet
Rapport
Berge, Jørgen; Schander, C; Pampanin, D.M.; Johnsen, Geir. (2007) The past, present and future of the Mytilus edulis population on Svalbard. In Proceedings from Arctic Frontiers: Balancing human use and ecosystem protection. UiT Norges arktiske universitet UiT Norges arktiske universitet
Rapport
Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2007) Bio-optical properties and spectral attenuation of photosynthetically available radiation: relation to primary productivity and phytoplankton composition. In Proceedings from Arctic Frontiers: balancing human use and ecosystem protection. UiT Norges arktiske universitet UiT Norges arktiske universitet
Rapport
Johnsen, Geir. (2007) Arctic Life: Bridging ecosystem function using remote sensing technologies. Svalbard Science Forum
Populærvitenskapelig artikkel
Carlsen, BP; Johnsen, Geir; Berge, Jørgen; Kuklinski, P. (2007) Biodiversity patterns of macro-epifauna on different lamina parts of Laminaria digitata and Saccharina latissima collected during spring and summer 2004 in Kongsfjorden, Svalbard. Polar Biology
Vitenskapelig artikkel
Volent, Z; Johnsen, Geir; Sigernes, Fred. (2007) Kelp forest mapping by use of airborne hyperspectral imager. Journal of Applied Remote Sensing
Vitenskapelig artikkel

2006

Sylling, Guro; Thingstad, Per Gustav; Johnsen, Geir. (2006) Marin bunndyrfauna (Gastropoda, Bivalvia) - Konsekvenser av åpning av veifylling over Ramsarområdet Tautrasvaet. NTNU, Institutt for biologi
Mastergradsoppgave
Carlsen, Beth Paludan; Johnsen, Geir. (2006) Makroepifauna associeret med Laminaria digitata og L. saccharina, Svalbard. NTNU, Institutt for biologi
Mastergradsoppgave
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Leder
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag; Pampanin, Daniella. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Vitenskapelig artikkel
Olsen, Lasse Mork; Öztürk, M.; Sakshaug, Egil; Johnsen, Geir. (2006) Photosynthesis-induced phosphate precipitation in seawater: ecological implications for phytoplankton. Marine Ecology Progress Series
Vitenskapelig artikkel
Rodriguez, F; Chauton, Matilde Skogen; Johnsen, Geir; Andresen, Kjersti; Olsen, Lasse Mork; Zapata, M.. (2006) Photoacclimation in phytoplankton: implications for biomass estimates, pigment functionality and chemotaxonomy. Marine Biology
Vitenskapelig artikkel
Roy, Suzanne; Egeland, Einar Skarstad; Johnsen, Geir; Llewellyn, Carole; Wright, Simon. (2006) Report of a Workshop on a Follow-Up Volume of the Book "Phytoplankton Pigments in Oceanography". Scientific Committee on Oceanic Research
Rapport
Johnsen, Geir. (2006) Warming Arctic sees return of blue mussels after 1000 years. National Geographic
Populærvitenskapelig artikkel
Onstad, L; Evertsen, Jussi; Johnsen, Geir. (2006) Snegle på solceller. Gemini
Populærvitenskapelig artikkel

2005

Hilstad, Kari; Johnsen, Geir. (2005) In situ tidsseriemålinger av lyshøstingsegenskaper og cellekjemi hos marine makroalger i Trondheimsfjorden. NTNU, Institutt for biologi
Hovedfagsoppgave
Olsen, Lasse Mork; Johnsen, Geir. (2005) Interactions between marine osmo- and phagotrophs in different physicochemical environments. NTNU, Institutt for biologi
Doktorgradsavhandling
Valle, Kristin Collier; Johnsen, Geir. (2005) Detection of monthly variation in marine red, brown and green macroalgae by means of in situ video, epifluorescence microscopy and numerical digital image analysis. NTNU, Institutt for biologi
Hovedfagsoppgave
Chauton, Matilde Skogen; Johnsen, Geir; Sakshaug, Egil. (2005) Nuclear Magnetic Resonance spectroscopy of marine microalgae: Metabolic profiling and species discrimination from High-resolution Magic Angle Spinning NMR analysis of whole-cell samples. NTNU, Institutt for biologi
Doktorgradsavhandling
Sakshaug, Egil; Johnsen, Geir. (2005) Absorption, fluorescence excitation and photoacclimation in phytoplankton. Multi-Science Publishing
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2005) Ocean temperature oscillations enable reappearance of blue mussels Mytilus edulis in Svalbard after 1000 year absence. Marine Ecology Progress Series
Vitenskapelig artikkel
Sakshaug, Egil; Johnsen, Geir. (2005) Algal cultures, Analogues of Blooms and Applications. Multi-Science Publishing Multi-Science Publishing
Vitenskapelig antologi/Konferanseserie
Berge, J; Johnsen, Geir; Nilsen, F; Gulliksen, B; Slagstad, D. (2005) Ocean temperature oscillations causes the reappearance of blue mussels in Svalbard after 1000 years of absence. Marine Ecology Progress Series
Vitenskapelig artikkel
Bordvik, Hans Otto; Johnsen, Geir. (2005) “En glupsk nellik”. NEWTON websider (NRK)
Populærvitenskapelig artikkel
Indergaard, M; Nordtvedt, M; Johnsen, Geir. (2005) Satellittmålinger for miljøet (SISCAL project, NTNU, IBI). Gemini
Populærvitenskapelig artikkel
Bordvik, Hans Otto; Johnsen, Geir. (2005) “Forskning og foto under vann”. NEWTON websider (NRK)
Populærvitenskapelig artikkel
Burghardt, Ingo; Evertsen, Jussi; Johnsen, Geir; Wägele, Heike. (2005) Solar powered seaslugs - Mutualistic symbiosis of aeolid nudibranchia (Mollusca, Gastropoda, Opisthobranchia) with Symbiodinium. Symbiosis
Vitenskapelig artikkel
Fossmark, Reidar; Johnsen, Geir; Waldum, Helge; Johannesen, Eli Marie. (2005) Rebound acid hypersecretion after long-term inhibition of gastric acid secretion. Alimentary Pharmacology and Therapeutics
Vitenskapelig artikkel

2004

Hancke, Torunn Beate; Johnsen, Geir. (2004) SISCAL processor evaluation document. www.siscal.net
Rapport
Chauton, Matilde Skogen; Tilstone, Gavin; Legrand, Catherine; Johnsen, Geir. (2004) Changes in pigmentation, bio-optical characteristics and photophysiology, during phytoflagellate succession in mesocosms. Journal of Plankton Research
Vitenskapelig artikkel

2003

Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL prototype evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
Vitenskapelig artikkel
Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL End User Requirement evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
Vitenskapelig artikkel
Chauton, Matilde Skogen; Optun, Odd Inge; Bathen, F. T; Volent, Z.; Gribbestad, Ingrid S.; Johnsen, Geir. (2003) HR MAS 1H NMR spectroscopy analysis of whole cells of marine microalgae. Marine Ecology Progress Series
Vitenskapelig artikkel
Figueroa, F. L.; Escassi, L.; Perez-Rodriguez, E.; Korbee, N.; Johnsen, Geir. (2003) Effects of the irradiance in the short-term on accumulation of mycosporine like amino acids in sun and shade species of the red algal genus Porphyra. Photochemistry and Photobiology
Vitenskapelig artikkel

2002

Johansen, Torunn Beate; Johnsen, Geir. (2002) End User Requirements document. [Mangler utgivernavn]
Rapport
Johansen, Torunn Beate; Johnsen, Geir. (2002) End User requirement evaluation document. [Mangler utgivernavn]
Rapport
Gileptis, Laura; Johnsen, Geir; Moxness, Helge; Norwich, Inger; Vangen, Steffen. (2002) Modul for mønstergjenkjenning/klassifisering i DynamicImager ved bruk av backpropagation-algoritmen. Piksel'n : Organ for NOBIM (Norsk forening for bildebehandling og mønstergjenkjenning)
Vitenskapelig artikkel
Millie, David; Schofield, Oscar; Kirkpatrick, Gary J.; Johnsen, Geir; Evens, Tim J.. (2002) Using absorbance and fluorescence spectra to discriminate microalgae. European journal of phycology
Vitenskapelig artikkel
Johnsen, Geir; Børsheim, Knut Yngve; Johansen, Torunn Beate. (2002) Production and mortality of phytoplankton and sea-ice microalgae in the southern ocean. Rapportserie (Norsk polarinstitutt)
Vitenskapelig artikkel

1992

Syvertsen, E.; Hegseth, E; Johnsen, Geir; Sakshaug, Egil; Gulliksen, B; Lønne, O. J. (1992) Livet i isen (The life in the ice). In Økosystem Barentshavet. [Mangler utgivernavn]
Fagbok
Sakshaug, Egil; Kristiansen, S; Syvertsen, E; Eilertsen, H. C; Gilstad, M; Hegseth, E. N. (1992) Planktonalger (Phytoplankton). In Økosystem Barentshavet. [Mangler utgivernavn]
Fagbok
Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1992) Bio-optical characteristicts of phytoplankton in relation to remote sensing. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
Vitenskapelig artikkel
Volent, Zsolt; Johnsen, Geir. (1992) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a moored buoy. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
Vitenskapelig artikkel
Johnsen, Geir; Sakshaug, Egil; Vernet, Maria. (1992) Pigment composition, spectral characteriation and photosynthetic parameters in Chrysochromulina polylepis. Marine Ecology Progress Series
Vitenskapelig artikkel

1991

Johnsen, Geir. (1991) Proceedings from a scientific working meeting. Fisken og Havet
Vitenskapelig artikkel
Johnsen, Geir; Hegseth, Else Nøst. (1991) Photoadaptation of sea-ice microalgae in the Barents Sea. Polar Biology
Vitenskapelig artikkel
Johnsen, Geir. (1991) Identification of Chrysochromulina leadbeateri by means of remote sensing. Fisken og Havet
Vitenskapelig artikkel
Sakshaug, Egil; Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1991) Identification of phytoplankton blooms by means of remote sensing. Environment Northern Seas
Vitenskapelig artikkel
Sakshaug, Egil; Johnsen, Geir; Andresen, Kjersti; Vernet, Maria. (1991) Modeling of light-dependent algal photosynthesis and growth: Experiments with the Barents Sea diatoms Thalassiosira nordensskioeldii and Chaetocero furcellatus. Deep-Sea Research Part II: Topical Studies in Oceanography
Vitenskapelig artikkel

Tidsskriftspublikasjoner

Williamson, David Roddan; Moreira Fragoso, Glaucia; Majaneva, Sanna Kristiina; Dallolio, Alberto; Halvorsen, Daniel Ørnes; Hasler, Oliver Kevin. (2023) Monitoring Algal Blooms with Complementary Sensors on Multiple Spatial and Temporal Scales. Oceanography
Vitenskapelig artikkel
Bakken, Sivert; Henriksen, Marie Bøe; Birkeland, Roger; Langer, Dennis David; Oudijk, Adriënne Esmeralda; Berg, Simen. (2023) HYPSO-1 CubeSat: First Images and In-Orbit Characterization. Remote Sensing
Vitenskapelig artikkel
Summers, Natalie Maria; Moreira Fragoso, Glaucia; Johnsen, Geir. (2023) Photophysiologically active green, red, and brown macroalgae living in the Arctic Polar Night. Scientific Reports
Vitenskapelig artikkel
Grant, Stephen Denis; Johnsen, Geir; McKee, David; Zolich, Artur Piotr; Cohen, Jonathan H.. (2023) Spectral and RGB analysis of the light climate and its ecological impacts using an all-sky camera system in the Arctic. Applied Optics
Vitenskapelig artikkel
Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte; Chierici, Melissa. (2023) Still Arctic? — The changing Barents Sea. Elementa: Science of the Anthropocene
Vitenskapelig oversiktsartikkel/review
Schartmuller, Bernhard; Anderson, Philip; Mckee, David; Connan-McGinty, Stacey; Kopec, Tomasz Piotr; Daase, Malin Hildegard Elisabeth. (2023) Development and calibration of a high dynamic range and autonomous ocean-light instrument to measure sub-surface profiles in ice-covered waters. Applied Optics
Vitenskapelig artikkel
Summers, Natalie; Johnsen, Geir; Mogstad, Aksel Alstad; Løvås, Håvard; Fragoso, Glaucia Moreira; Berge, Jørgen. (2022) Underwater Hyperspectral Imaging of Arctic Macroalgal Habitats during the Polar Night Using a Novel Mini-ROV-UHI Portable System. Remote Sensing
Vitenskapelig artikkel
Fragoso, Glaucia Moreira; Davies, Emlyn John; Fossum, Trygve Olav; Ullgren, Jenny; Majaneva, Sanna; Aberle-Malzahn, Nicole. (2022) Contrasting phytoplankton-zooplankton distributions observed through autonomous platforms, in-situ optical sensors and discrete sampling. PLOS ONE
Vitenskapelig artikkel
Mogstad, Aksel Alstad; Løvås, Håvard; Sture, Øystein; Johnsen, Geir; Ludvigsen, Martin. (2022) Remote Sensing of the Tautra Ridge: An Overview of the World’s Shallowest Cold-Water Coral Reefs. Frontiers in Marine Science
Vitenskapelig artikkel
Connan-McGinty, Stacey; Banas, Neil S.; Berge, Jørgen; Cottier, Finlo Robert; Grant, Stephen; Johnsen, Geir. (2022) Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea. Journal of Advances in Modeling Earth Systems
Vitenskapelig artikkel
Oudijk, Esmée; Hasler, Oliver Kevin; Øveraas, Henning; Marty, Sabine; Williamson, David Roddan; Svendsen, Torbjørn Karl. (2022) Campaign For Hyperspectral Data Validation In North Atlantic Coastal Waters. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Vitenskapelig artikkel
Dona, Angela; Evertsen, Jussi; Johnsen, Geir. (2022) The role of parapodia and lack of photoacclimation in kleptoplasts of the sacoglossan sea slug Plakobranchus ocellatus. Coral reefs
Vitenskapelig artikkel
Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura. (2021) Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night. PLoS Biology
Vitenskapelig artikkel
Cardwell, CR; Berge, Jørgen; Johnsen, Geir. (2021) Arctic voyage shines light on some cold, hard truths. The Herald, UK
Populærvitenskapelig artikkel
Bazilchuk, Nancy Reney; Berge, Jørgen; Johnsen, Geir. (2021) Lysforurensning I Arktis kan ha ødelagt forskningsresultater. Gemini.no
Populærvitenskapelig artikkel
Ringvold, Halldis; Taite, Morag; Allcock, A. Louise; Vecchione, Michael; Péan, Michel; Sandulli, Roberto. (2021) In situ recordings of large gelatinous spheres from NE Atlantic, and the first genetic confirmation of egg mass of Illex coindetii (Vérany, 1839) (Cephalopoda, Mollusca). Scientific Reports
Vitenskapelig artikkel
Bakken, Sivert; Johnsen, Geir; Johansen, Tor Arne. (2021) Analysis and Model Development of Direct Hyperspectral Chlorophyll-A Estimation for Remote Sensing Satellites. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
Vitenskapelig artikkel
Horni, K; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin. (2021) Internasjonalt forskningsmiljø dykker i Mjøsa etter at Oppland Arbeiderblad skrev om forurensning. Oppland arbeiderblad
Populærvitenskapelig artikkel
Bazilchuk, Nancy Reney; Stahl, Annette; Johnsen, Geir; Saad, Aya; Thu, Maren; Nøland, Annecken. (2021) Sporhunden som lukter mikroalger. . Gemini.no
Populærvitenskapelig artikkel
Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan H.; Mckee, David. (2021) All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic. Applied Optics
Vitenskapelig artikkel
Geoffroy, Maxime; Langbehn, Tom Jasper; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault. (2021) Pelagic organisms avoid white, blue, and red artificial light from scientific instruments. Scientific Reports
Vitenskapelig artikkel
Løvås, Håvard; Mogstad, Aksel Alstad; Sørensen, Asgeir Johan; Johnsen, Geir. (2021) A Methodology for Consistent Georegistration in Underwater Hyperspectral Imaging. IEEE Journal of Oceanic Engineering
Vitenskapelig artikkel
Faltynkova, Andrea; Johnsen, Geir; Wagner, Martin. (2021) Hyperspectral imaging as an emerging tool to analyze microplastics: A systematic review and recommendations for future development. Microplastics and Nanoplastics
Vitenskapelig oversiktsartikkel/review
Ramirez-Llodra, Eva; Hilário, Ana; Paulsen, Emil; Costa, Carolina; Bakken, Torkild; Johnsen, Geir. (2020) Benthic Communities on the Mohn’s Treasure Mound: Implications for Management of Seabed Mining in the Arctic Mid-Ocean Ridge. Frontiers in Marine Science
Vitenskapelig artikkel
Gibbens, Sarah; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2020) As the Arctic warms, light pollution may pose a new treat to marine life. . National Geographic
Intervju tidsskrift
Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.. (2020) Artificial light during the polar night disrupts Arctic fish and zooplankton behavior down to 200 m depth. Communications Biology
Vitenskapelig artikkel
Saad, Aya; Stahl, Annette; Våge, Andreas; Davies, Emlyn John; Nordam, Tor; Aberle-Malzahn, Nicole. (2020) Advancing Ocean Observation with an AI-driven Mobile Robotic Explorer. Oceanography
Vitenskapelig artikkel
Fragoso, Glaucia Moreira; Johnsen, Geir; Chauton, Matilde Skogen; Cottier, Finlo Robert; Ellingsen, Ingrid H.. (2020) Phytoplankton community succession and dynamics using optical approaches. Continental Shelf Research
Vitenskapelig artikkel
Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan. (2020) Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots. Remote Sensing
Vitenskapelig artikkel
Fragoso, Glaucia Moreira; Davies, Emlyn John; Ellingsen, Ingrid H.; Chauton, Matilde Skogen; Fossum, Trygve Olav; Ludvigsen, Martin. (2019) Physical controls on phytoplankton size structure, photophysiology and suspended particles in a Norwegian biological hotspot. Progress in Oceanography
Vitenskapelig artikkel
Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2019) Sea surface microlayer and elemental composition in phaeo-, chloro-, and rhodophytes in winter and spring. Journal of Phycology
Vitenskapelig artikkel
Mogstad, Aksel Alstad; Johnsen, Geir; Ludvigsen, Martin. (2019) Shallow-Water Habitat Mapping using Underwater Hyperspectral Imaging from an Unmanned Surface Vehicle: A Pilot Study. Remote Sensing
Vitenskapelig artikkel
Kauko, Hanna Maria; Pavlov, Alexey; Johnsen, Geir; Granskog, Mats; Peeken, Ilka; Assmy, Philipp. (2019) Photoacclimation state of an Arctic underice phytoplankton bloom. Journal of Geophysical Research (JGR): Oceans
Vitenskapelig artikkel
Bazilchuk, Nancy Reney; Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Ludvigsen, Martin; Johnsen, Geir. (2019) Smart undervannsrobot leter etter plankton. Av N Bazilchuk. Forskning.no. Angående NTNU Entice prosjekt publisert i Science Robotics. Forskning.no
Populærvitenskapelig artikkel
Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Davies, Emlyn John; Ullgren, Jenny; Mendes, Renato; Johnsen, Geir. (2019) Toward adaptive robotic sampling of phytoplankton in the coastal ocean. Science robotics
Vitenskapelig artikkel
Fragoso, Glaucia Moreira; Poulton, Alex James; Pratt, Nicola Jane; Johnsen, Geir; Purdie, Duncan Alastair. (2019) Trait-based analysis of subpolar North Atlantic phytoplankton and plastidic ciliate communities using automated flow cytometer. Limnology and Oceanography
Vitenskapelig artikkel
Fragoso, Glaucia Moreira; Poulton, Alex J.; Yashayaev, Igor M.; Head, Erica J.H.; Johnsen, Geir; Purdie, Duncan A.. (2018) Diatom biogeography from the Labrador Sea revealed through a trait-based approach. Frontiers in Marine Science
Vitenskapelig artikkel
Dumke, Ines; Nornes, Stein Melvær; Purser, Autun; Marcon, Yann; Ludvigsen, Martin; Ellefmo, Steinar Løve. (2018) First hyperspectral imaging survey of the deep seafloor: High-resolution mapping of manganese nodules. Remote Sensing of Environment
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning - enda en kilde til bekymring. Svalbardposten
Kronikk
Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning truer livet i Arktis. Aftenposten Viten
Kronikk
Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; De La Torre, Pedro R.; Nornes, Stein Melvær. (2018) Use of an autonomous surface vehicle reveals small-scale diel vertical migrations of zooplankton and susceptibility to light pollution under low solar irradiance. Science Advances
Vitenskapelig artikkel
Ødegård, Øyvind; Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging: a new tool for marine archaeology. Applied Optics
Vitenskapelig artikkel
Fossum, Trygve Olav; Eidsvik, Jo; Ellingsen, Ingrid H.; Alver, Morten; Fragoso, Glaucia Moreira; Johnsen, Geir. (2018) Information-driven robotic sampling in the coastal ocean. Journal of Field Robotics (JFR)
Vitenskapelig artikkel
Kauko, Hanna Maria; Olsen, Lasse Mork; Duarte, Pedro; Peeken, Ilka; Granskog, Mats A.; Johnsen, Geir. (2018) Algal colonization of young arctic sea ice in spring. Frontiers in Marine Science
Vitenskapelig artikkel
Dumke, Ines; Purser, Autun; Marcon, Yann; Nornes, Stein Melvær; Johnsen, Geir; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging as an in situ taxonomic tool for deep-sea megafauna. Scientific Reports
Vitenskapelig artikkel
Liefmann, Stephanie; Järnegren, Johanna; Johnsen, Geir; Murray, Fiona. (2018) Eco-physiological responses of cold-water soft corals to anthropogenic sedimentation and particle shape. Journal of Experimental Marine Biology and Ecology
Vitenskapelig artikkel
Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Langbehn, Tom; Cottier, Finlo Robert. (2018) Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic. Polar Biology
Short communication
Johnsen, Geir; Norli, Marit; Moline, Mark A.; Robbins, Ian; Quillfeldt, Cecilie von; Sørensen, Kai. (2018) The advective origin of an under-ice spring bloom in the Arctic Ocean using multiple observational platforms. Polar Biology
Vitenskapelig artikkel
Dumke, Ines; Ludvigsen, Martin; Ellefmo, Steinar Løve; Søreide, Fredrik; Johnsen, Geir; Murton, Bramley J.. (2018) Underwater Hyperspectral Imaging Using a Stationary Platform in the Trans-Atlantic Geotraverse Hydrothermal Field. IEEE Transactions on Geoscience and Remote Sensing
Vitenskapelig artikkel
Gabrielsen, Tove M.; Johnsen, Geir. (2018) Skogen på Svalbard. Svalbardposten
Populærvitenskapelig artikkel
Otterlei, Inger; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin; Hareide, Nils Roar; Christensen-Dalsgaard, Signe. (2017) 300 000 sjøfugl er forsvunnet fra Runde. Sunnmørsposten
Intervju tidsskrift
Johnsen, Geir; Christiansen, Hanne H; Ravolainen, Virve; Reymert, Per Kyrre; Jenssen, Eva Therese; Arlov, Thor Bjørn. (2017) Utfordrende natur og sikkerhet på Svalbard. Svalbardposten
Kronikk
Ostaszewska, Kaja; Balazy, Piotr; Berge, Jørgen; Johnsen, Geir; Staven, Robert. (2017) Seabirds during Arctic Polar Night: underwater observations from Svalbard archipelago, Norway. Waterbirds (De Leon Springs, Fla.)
Vitenskapelig artikkel
Kauko, Hanna Maria; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C.J.; Duarte, Pedro. (2017) Windows in Arctic sea ice: light transmission and ice algae in a refrozen lead. Journal of Geophysical Research (JGR): Biogeosciences
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir. (2017) Kunnskapshull om livet i Arktis i mørketiden. Aftenposten Viten
Kronikk
Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher John. (2017) Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic. Scientific Reports
Vitenskapelig artikkel
Mogstad, Aksel Alstad; Johnsen, Geir. (2017) Spectral characteristics of coralline algae: a multi-instrumental approach, with emphasis on underwater hyperspectral imaging. Applied Optics
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir. (2017) Om bambus, spøkelseskreps og et Arktis i endring. Svalbardposten
Kronikk
Berge, Jørgen; Johnsen, Geir. (2017) Superkommunisten. Svalbardposten
Kronikk
Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) Opp fra polarnattens mørke. Aftenposten Viten
Kronikk
Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) A bitter-sweet symphony. Svalbardposten
Kronikk
Berge, Jørgen; Geoffroy, Maxime; Johnsen, Geir; Cottier, Finlo Robert; Bluhm, Bodil; Vogedes, Daniel Ludwig. (2016) Ice-tethered observational platforms in the Arctic Ocean pack ice. IFAC-PapersOnLine
Vitenskapelig artikkel
Cronin, Heather; Cohen, Jonathan H.; Berge, Jørgen; Johnsen, Geir; Moline, Mark A.. (2016) Bioluminescence as an ecological factor during high Arctic polar night. Scientific Reports
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Ludvigsen, Martin; Cohen, Jonathan. (2016) Design for latskap - men med store muligheter. Svalbardposten
Kronikk
Bondø, Tor-Hartvig; Johnsen, Geir; Berge, Jørgen. (2016) Fant yrende liv i polarnatta. VG : Verdens gang
Populærvitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir. (2016) Mørkets fyrster med påskrudd lys. Svalbardposten
Populærvitenskapelig artikkel
Bazilchuk, Nancy Reney; Leite, Stein Roar; Johnsen, Geir; Kjeken, John; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2016) Bomber og buss på havbunnen. Gemini
Populærvitenskapelig artikkel
Haudemann-Andersen, Jørn; Lystad, M S; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2016) Blå lys i det kalde dyp. NRK Trøndelag, Nyheter
Populærvitenskapelig artikkel
Haugstad, Tor; Erdal, Ivar; Johnsen, Geir; Sørensen, Asgeir Johan; Fjærvik, Nils. (2016) Gründerne mener dette kameraet kan bli det nye ekkoloddet – Ecotone er kandidat til TU Tech Award. Teknisk Ukeblad
Populærvitenskapelig artikkel
Bjørgan, Espen Halvorsen; Johnsen, Geir; Kjeken, Jon; Ludvigsen, Martin. (2016) Fant buss på 600 m dybde. Adresseavisen
Populærvitenskapelig artikkel
Johnsen, Geir; Ludvigsen, Martin; Sørensen, Asgeir Johan; Aas, Lars Martin Sandvik. (2016) The use of underwater hyperspectral imaging deployed on remotely operated vehicle – methods and applications. IFAC-PapersOnLine
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Kinderegg i polarnatten. Svalbardposten
Kronikk
Donahue, Michelle; Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) The age of humans - living in the anthropocene - "Termites of the sea" found munching wood near Arctic shipwrecks. Smithsonian
Populærvitenskapelig artikkel
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Dark lords, werewolves and Indiana Jones in the polar night. Gemini (English edition)
Intervju tidsskrift
Krüger, Frida Jørstad; Johnsen, Geir; Kjeken, John; Ludvigsen, Martin. (2016) Gammel buss ble korallrev. NRK Viten
Populærvitenskapelig artikkel
Kokkegård, Hanne; Johnsen, Geir; Ludvigsen, Martin; Torre, Pedro De La. (2016) Vitenskab - Bomber fra 2 verdenskrig danner koralrev på 600 m dybde. Danmarks radio
Populærvitenskapelig artikkel
Haugstad, Tormod; Erdal, Ivar; Johnsen, Geir. (2016) Kameraet deres «kan bli det nye ekkoloddet». Nå er det norske selskapet i ferd med å lykkes. Teknisk Ukeblad
Intervju tidsskrift
Johnsen, Geir. (2016) Yrende liv i Isfjorden. Svalbardposten
Populærvitenskapelig artikkel
Aarskog, Karine Nigar; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2016) Et stort løft for arktisk forskning (NTNU & UiT). Universitetet i Tromsø
Fagartikkel
Berge, Jørgen; Falk-Petersen, Stig; Renaud, Paul E.; Daase, Malin; Geoffroy, Maxime; Johnsen, Geir. (2016) En reise mot Ultima Thule. Svalbardposten
Populærvitenskapelig artikkel
Lervik, Frank; Johnsen, Geir; Ludvigsen, Martin; Kjeken, John. (2016) Det ligger flere busser der. Adresseavisen
Populærvitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Mark spiser opp vrak på havbunnen. Fiskaren
Populærvitenskapelig artikkel
Kintisch, Eli; Berge, Jørgen; Last, Kim; Cohen, Jonathan; Johnsen, Geir. (2016) Voyage into darkness . Science
Intervju tidsskrift
Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Ludvigsen, Martin; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Mørkets fyrster, varulver og Indiana Jones. Gemini
Populærvitenskapelig artikkel
Berge, Jørgen; Renaud, Paul E.; Johnsen, Geir; Darnis, Gerald; Geoffroy, Maxime; Daase, Malin. (2016) I grenselandet (mellom Tull og Thule). Svalbardposten
Populærvitenskapelig artikkel
Førde, Henny; Forbord, Silje; Handå, Aleksander; Fossberg, Julia; Arff, Johanne; Johnsen, Geir. (2016) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. Journal of Applied Phycology
Vitenskapelig artikkel
Nilssen, Ingunn; Dos Santos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral, Marcelo M.; Eide, Ingvar. (2015) Assessing the potential impact of water-based drill cuttings on deep water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
Vitenskapelig artikkel
Nilssen, Ingunn; Santos dos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral Montenegro, Marcelo; Eide, Ingvar. (2015) Assessing the potential impact of water-based drill cuttings on deep-water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan; Nilssen, Ingunn. (2015) Enabling technology for Arctic research. Pan European Networks: Science and Techology Magazine
Vitenskapelig oversiktsartikkel/review
Rodriguez, Francisco; Garrido, J.L.; Sabrino, C; Johnsen, Geir; Riobo, P; Franco, J. (2015) Divinyl chlorophyll a in the marine eukaryotic protist Alexandrium ostenfeldii (Dinophyceae). Environmental Microbiology
Vitenskapelig artikkel
Nilssen, Ingunn; Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Moline, Mark A.; Berge, Jørgen. (2015) Integrated environmental mapping and monitoring, a methodological approach to optimise knowledge gathering and sampling strategy. Marine Pollution Bulletin
Vitenskapelig artikkel
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig. (2015) Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton?. PLOS ONE
Vitenskapelig artikkel
Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.. (2015) In the dark: a review of ecosystem processes during the Arctic polar night. Progress in Oceanography
Vitenskapelig artikkel
Berge, Jørgen; Daase, Malin; Renaud, Paul; Ambrose, William G. Jr.; Darnis, Gérald; Last, Kim S. (2015) Unexpected levels of biological activity during the polar night offer new perspectives on a warming Arctic. Current Biology
Vitenskapelig artikkel
Pettersen, Ragnhild; Johnsen, Geir; Bruheim, Per; Andreassen, Trygve. (2014) Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organisms. Organisms Diversity & Evolution
Vitenskapelig artikkel
Valle, Kristin Collier; Nymark, Marianne; Aamot, Inga; Hancke, Kasper; Winge, Per; Andresen, Kjersti. (2014) System responses to equal doses of photosynthetically usable radiation of blue, green, and red light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
Vitenskapelig artikkel
Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Lågstad, Petter Arthur; Ødegård, Øyvind. (2014) Scientific Operations Combining ROV and AUV in the Trondheim Fjord. Marine Technology Society journal
Vitenskapelig artikkel
Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Glowing in the dark: Discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
Vitenskapelig artikkel
Hansen, Ingrid; Pettersen, Ragnhild; Beuchel, Frank; Cochrane, Sabine; Frantzen, marianne; Ekehaug, Stefan. (2014) Underwater hyperspectral imaging (UHI) for environmental mapping and monitoring of seabed habitats. Ocean Optics
Sammendrag/abstract
Cohen, Jonathan; Cronin, Heather; Moline, Mark A.; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Are krill eyes useful in the high Arctic polar night?. Ocean Optics
Sammendrag/abstract
Johnsen, Geir; Ekehaug, Stefan; Hansen, Ingrid; Sørensen, Asgeir Johan. (2014) The use of underwater hyperspectral imaging deployed on remotely operated vehicles to identify, map and monitor bio-geo-chemical objects of interest. Ocean Optics
Sammendrag/abstract
Aamot, Inga; Pokrzywinski, Kaytee; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan. (2014) Light Climate and Status of the Photosynthetic Machinery in Macroalgae in the Polar Night. Ocean Optics
Sammendrag/abstract
Nornes, Stein Melvær; Candeloro, Mauro; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Photomosaic camera as simultaneous data collector and navigation aid on unmanned underwater vehicles. Ocean Optics
Sammendrag/abstract
Nilssen, Ingunn; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen; Nornes, Stein Melvær. (2014) Integrated environmental monitoring; a methodological approach to optimise knowledge gathering and sampling strategy. Ocean Optics
Sammendrag/abstract
Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Erratum to: Glowing in the dark: discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
Errata
Berge, Jørgen; Cottier, Finlo; Varpe, Øystein; Renaud, Paul; Falk-Petersen, Stig; Kwasniewski, Sawomir. (2014) Arctic complexity: A case study on diel vertical migration of zooplankton. Journal of Plankton Research
Vitenskapelig artikkel
Hancke, Kasper; Hovland, Erlend Kjeldsberg; Volent, Zsolt; Pettersen, Ragnhild; Johnsen, Geir; Moline, Mark A.. (2014) Optical properties of CDOM across the Polar Front in the Barents Sea: Origin, distribution and significance. Journal of Marine Systems
Vitenskapelig artikkel
Hovland, Erlend Kjeldsberg; Hancke, Kasper; Alver, Morten; Drinkwater, Kennneth F.; Høkedal, Jo; Johnsen, Geir. (2014) Optical impact of an Emiliania huxleyi bloom in the frontal region of the Barents Sea. Journal of Marine Systems
Vitenskapelig artikkel
Båtnes, Anna Solvang; Miljeteig, Cecilie; Berge, Jørgen; Greenacre, Michael; Johnsen, Geir. (2013) Quantifying the light sensitivity of Calanus spp. during the polar night: potential for orchestrated migrations conducted by ambient light from the sun, moon, or aurora borealis. Polar Biology
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Falk-Pettersen, Stig. (2013) Mørkets hemmeligheter. Svalbardposten
Populærvitenskapelig artikkel
Nymark, Marianne; Valle, Kristin Collier; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir. (2013) Molecular and photosynthetic responses to prolonged darkness and subsequent acclimation to re-illumination in the diatom Phaeodactylum tricornutum. PLOS ONE
Vitenskapelig artikkel
Hovland, Erlend Kjeldsberg; Dierssen, Heidi; Ferreira, Ana Sofia; Johnsen, Geir. (2013) Dynamics regulating major trends in Barents Sea temperatures and subsequent effect on remotely sensed particulate inorganic carbon. Marine Ecology Progress Series
Vitenskapelig artikkel
Berge, Jørgen; Båtnes, Anna Solvang; Johnsen, Geir; Blackwell, Susan; Moline, Mark A.. (2012) Bioluminescence in the high Arctic during the polar night. Marine Biology
Vitenskapelig artikkel
Gabrielsen, Tove M; Quillfeldt, Cecilie von; Johnsen, Geir; Berge, Jørgen. (2012) Varm vinter, sen vår i fjorden. Svalbardposten
Leserinnlegg
Elde, Anette; Pettersen, Ragnhild; Bruheim, Per; Järnegren, Johanna; Johnsen, Geir. (2012) Pigmentation and Spectral Absorbance Signatures in Deep-Water Corals from the Trondheimsfjord, Norway. Marine Drugs
Vitenskapelig artikkel
Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2011) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
Vitenskapelig artikkel
Volent, Zsolt; Johnsen, Geir; Hovland, Erlend Kjeldsberg; Folkestad, Are; Olsen, Lasse Mork; Tangen, Karl. (2011) Improved monitoring of phytoplankton bloom dynamics in a Norwegian fjord by integrating satellite data, pigment analysis, and Ferrybox data with a coastal observation network. Journal of Applied Remote Sensing
Vitenskapelig artikkel
Jouenne, Fabien; Eikrem, Wenche; Le Gall, F; Marie, Dominique; Johnsen, Geir; Vaulot, Daniel. (2011) Prasinoderma singularis sp. nov. (Prasinophyceae, Chlorophyta), a Solitary Coccoid Prasinophyte from the South-East Pacific Ocean. Protist
Vitenskapelig artikkel
Pettersen, Ragnhild; Johnsen, Geir; Berge, Jørgen; Hovland, Erlend Kjeldsberg. (2011) Phytoplankton chemotaxonomy in waters around the Svalbard archipelago reveals high amounts of Chl b and presence of gyroxanthin-diester. Polar Biology
Vitenskapelig artikkel
Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2010) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
Vitenskapelig artikkel
Aamot, Inga; Berge, Jørgen; Hancke, Kasper; Johnsen, Geir; Moline, Mark; Schofield, Oscar. (2010) NORUS - Technology Development for Marine Monitoring and Ocean Observation:An North America-Norway educational program. http://ipy-osc.no/abstract/
Sammendrag/abstract
Johnsen, Geir; Søreide, Fredrik. (2010) Underwater hyperspectral imaging of marine mineral deposits. Underwater Mining meeting Institute (UMI)
Sammendrag/abstract
Berge, Jørgen; Cottier, Finlo; Last, Kim S.; Varpe, Øystein; Leu, Eva; Søreide, Janne. (2009) Diel vertical migration of Arctic zooplankton during the polar night. Biology Letters
Vitenskapelig artikkel
Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Winge, Per; Hancke, Kasper; Andresen, Kjersti. (2009) An integrated analysis of molecular acclimation to high light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
Vitenskapelig artikkel
Berge, Jørgen; Lønne, Ole Jørgen; Renaud, Paul; Johnsen, Geir; Gulliksen, Bjørn; Varpe, Øystein. (2009) Polartorsken - vil den bli utkonkurrert av sørlige fiskearter?. Svalbardposten
Populærvitenskapelig artikkel
Evertsen, Jussi; Johnsen, Geir. (2009) In vivo and in vitro differences in chloroplast functionality in the two north Atlantic sacoglossans (Gastropoda, Opisthobranchia) Placida dendritica and Elysia viridis. Marine Biology
Vitenskapelig artikkel
Volent, Z; Johnsen, Geir; Sigernes, Fred. (2009) Microscopic hyperspectral imaging used as a bio-optical taxonomic tool for micro- and macroalgae. Applied Optics
Vitenskapelig artikkel
Hancke, Torunn Beate; Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2008) Rate of O2 production derived from pulse-amplitude-modulated fluorescence: Testing three biooptical approaches against measured O2-production rate. Journal of Phycology
Vitenskapelig artikkel
Bredholt, Harald; Fjærvik, Espen; Johnsen, Geir; Zotchev, Sergey. (2008) Actinomycetes from sediments in the Trondheim Fjord, Norway: Diversity and biological activity. Marine Drugs
Vitenskapelig artikkel
Bakken, Torkild; Evertsen, Jussi; Johnsen, Geir. (2008) Vitenskapelig dykking - behov for endringer i forskriften. Dykkenytt : informasjonsorgan for dykkeindustrien
Fagartikkel
Hancke, Kasper; Hancke, Torunn Beate; Olsen, Lasse Mork; Johnsen, Geir; Glud, RN. (2008) Temperature effects on microalgal photosynthesis-light responses measured by O2 production, pulse-amplitude-modulated fluorescence, and C-14 assimilation. Journal of Phycology
Vitenskapelig artikkel
Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark. (2008) Combined use of AUV and hyperspectral imaging to mapping sea-surface and macroalgae. Ocean Optics
Sammendrag/abstract
Cibic, Tamara; Blasutto, Oriana; Hancke, Kasper; Johnsen, Geir. (2007) Microphytobenthic species composition, pigment concentration, and primary production in sublittoral sediments of the Trondheimsfjord (Norway). Journal of Phycology
Vitenskapelig artikkel
Evertsen, Jussi; Burghardt, Ingo; Johnsen, Geir; Wägele, Heike. (2007) Retention of functional chloroplasts in some sacoglossans from the Indo-Pacific and Mediterranean. Marine Biology
Vitenskapelig artikkel
Ludvigsen, Martin; Sortland, Bjørn; Johnsen, Geir; Singh, Hanumant. (2007) Applications of Geo-Referenced Underwater Photo Mosaics in Marine Biology and Archaeology. Oceanography
Vitenskapelig artikkel
Johnsen, Geir; Sakshaug, Egil. (2007) Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse-amplitude-modulated and fast-repetition-rate fluorometry. Journal of Phycology
Vitenskapelig artikkel
Edvardsen, B; Eikrem, W; Shalchian-Tabrizi, K; Riisberg, I; Johnsen, Geir; Naustvoll, L. (2007) Verrucophora farcimen gen. et sp nov (Dictyochophyceae, Heterokonta) - A bloom-forming ichthyotoxic flagellate from the Skagerrak, Norway. Journal of Phycology
Vitenskapelig artikkel
Johnsen, Geir. (2007) Arctic Life: Bridging ecosystem function using remote sensing technologies. Svalbard Science Forum
Populærvitenskapelig artikkel
Carlsen, BP; Johnsen, Geir; Berge, Jørgen; Kuklinski, P. (2007) Biodiversity patterns of macro-epifauna on different lamina parts of Laminaria digitata and Saccharina latissima collected during spring and summer 2004 in Kongsfjorden, Svalbard. Polar Biology
Vitenskapelig artikkel
Volent, Z; Johnsen, Geir; Sigernes, Fred. (2007) Kelp forest mapping by use of airborne hyperspectral imager. Journal of Applied Remote Sensing
Vitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Leder
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag; Pampanin, Daniella. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
Vitenskapelig artikkel
Olsen, Lasse Mork; Öztürk, M.; Sakshaug, Egil; Johnsen, Geir. (2006) Photosynthesis-induced phosphate precipitation in seawater: ecological implications for phytoplankton. Marine Ecology Progress Series
Vitenskapelig artikkel
Rodriguez, F; Chauton, Matilde Skogen; Johnsen, Geir; Andresen, Kjersti; Olsen, Lasse Mork; Zapata, M.. (2006) Photoacclimation in phytoplankton: implications for biomass estimates, pigment functionality and chemotaxonomy. Marine Biology
Vitenskapelig artikkel
Johnsen, Geir. (2006) Warming Arctic sees return of blue mussels after 1000 years. National Geographic
Populærvitenskapelig artikkel
Onstad, L; Evertsen, Jussi; Johnsen, Geir. (2006) Snegle på solceller. Gemini
Populærvitenskapelig artikkel
Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2005) Ocean temperature oscillations enable reappearance of blue mussels Mytilus edulis in Svalbard after 1000 year absence. Marine Ecology Progress Series
Vitenskapelig artikkel
Berge, J; Johnsen, Geir; Nilsen, F; Gulliksen, B; Slagstad, D. (2005) Ocean temperature oscillations causes the reappearance of blue mussels in Svalbard after 1000 years of absence. Marine Ecology Progress Series
Vitenskapelig artikkel
Bordvik, Hans Otto; Johnsen, Geir. (2005) “En glupsk nellik”. NEWTON websider (NRK)
Populærvitenskapelig artikkel
Indergaard, M; Nordtvedt, M; Johnsen, Geir. (2005) Satellittmålinger for miljøet (SISCAL project, NTNU, IBI). Gemini
Populærvitenskapelig artikkel
Bordvik, Hans Otto; Johnsen, Geir. (2005) “Forskning og foto under vann”. NEWTON websider (NRK)
Populærvitenskapelig artikkel
Burghardt, Ingo; Evertsen, Jussi; Johnsen, Geir; Wägele, Heike. (2005) Solar powered seaslugs - Mutualistic symbiosis of aeolid nudibranchia (Mollusca, Gastropoda, Opisthobranchia) with Symbiodinium. Symbiosis
Vitenskapelig artikkel
Fossmark, Reidar; Johnsen, Geir; Waldum, Helge; Johannesen, Eli Marie. (2005) Rebound acid hypersecretion after long-term inhibition of gastric acid secretion. Alimentary Pharmacology and Therapeutics
Vitenskapelig artikkel
Chauton, Matilde Skogen; Tilstone, Gavin; Legrand, Catherine; Johnsen, Geir. (2004) Changes in pigmentation, bio-optical characteristics and photophysiology, during phytoflagellate succession in mesocosms. Journal of Plankton Research
Vitenskapelig artikkel
Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL prototype evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
Vitenskapelig artikkel
Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL End User Requirement evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
Vitenskapelig artikkel
Chauton, Matilde Skogen; Optun, Odd Inge; Bathen, F. T; Volent, Z.; Gribbestad, Ingrid S.; Johnsen, Geir. (2003) HR MAS 1H NMR spectroscopy analysis of whole cells of marine microalgae. Marine Ecology Progress Series
Vitenskapelig artikkel
Figueroa, F. L.; Escassi, L.; Perez-Rodriguez, E.; Korbee, N.; Johnsen, Geir. (2003) Effects of the irradiance in the short-term on accumulation of mycosporine like amino acids in sun and shade species of the red algal genus Porphyra. Photochemistry and Photobiology
Vitenskapelig artikkel
Gileptis, Laura; Johnsen, Geir; Moxness, Helge; Norwich, Inger; Vangen, Steffen. (2002) Modul for mønstergjenkjenning/klassifisering i DynamicImager ved bruk av backpropagation-algoritmen. Piksel'n : Organ for NOBIM (Norsk forening for bildebehandling og mønstergjenkjenning)
Vitenskapelig artikkel
Millie, David; Schofield, Oscar; Kirkpatrick, Gary J.; Johnsen, Geir; Evens, Tim J.. (2002) Using absorbance and fluorescence spectra to discriminate microalgae. European journal of phycology
Vitenskapelig artikkel
Johnsen, Geir; Børsheim, Knut Yngve; Johansen, Torunn Beate. (2002) Production and mortality of phytoplankton and sea-ice microalgae in the southern ocean. Rapportserie (Norsk polarinstitutt)
Vitenskapelig artikkel
Wägele, Heike; Johnsen, Geir. (2001) New results on histology and photosynthetic performance of solar-powered� opisthobranchs (Mollusca, Gastropoda, Opisthobranchia) containing symbiotic chloroplasts or zooxanthellae. Organisms Diversity & Evolution
Vitenskapelig artikkel
Legrand, Catherine; Johnsen, Geir; Graneli, Edna; Sakshaug, Egil. (2001) (Proceedings of the 9th International conference on Harmful Algal Blooms. Hobart, Tasmania, 7-11 February 2000.) Effect of polyamines on growth and toxicity of Chrysochromulina leadbeateri, Haptophytae. Phycologia
Vitenskapelig artikkel
Graneli, Edna; Legrand, Catherine; Carlsson, Per; Johnsen, Geir; Maestrini, Serge Y.; Reichelt, Michael. (2001) (Proceedings of the 9th International conference on Harmful Algal Blooms. Hobart, Tasmania, 7-11 February 20). Structuration of marine phytoplankton communities subjected to different levels of N, P and Si limitation in a mesocosm experiment (summary paper). Phycologia
Vitenskapelig artikkel
Legrand, Catherine; Johansson, Niclas; Johnsen, Geir; Børsheim, Knut Yngve; Graneli, Edna. (2001) Phagotrophy and toxicity in the photosynthetic Prymnesium patelliferum (Haptophyte). Limnology and Oceanography
Vitenskapelig artikkel
Seppala, J; Johnsen, Geir; Babichenko, S; Leeben, A; Poryvkina, L; Shalapyonok, [Mangler fornavn]. (1998) In vivo light absorption by photosynthetic and photoprotective algal pigments: Methodology and the effects of light acclimation and nutrient limitation. Report Series in Geophysics
Vitenskapelig artikkel
Johnsen, Geir; Dalløkken, Runar; Aure, J; Skjoldal, H. R. (1998) Photophysiology and environmental conditions during a toxic bloom of Chrysochromulina leadbeateri (Prymnesiophyceae). International symposium on Harmful Algal Blooms
Vitenskapelig artikkel
Johnsen, Geir; Eikrem, W.; Dalløkken, R.; Aure, J.; Skjoldal, H. R.. (1998) Physiology and environmental conditions during a toxic blooms of Chrysochromulina leadbeateri Prymnesiophyceae. Journal of Phycology
Vitenskapelig artikkel
Grzymski, J.; Johnsen, Geir; Sakshaug, Egil. (1997) The significance of intracellular self-shadingon the bio-optical properties of brown, red and green macroalgal species. Journal of Phycology
Vitenskapelig artikkel
Johnsen, Geir; Prezelin, B. B.; Jovine, R. V. M.. (1997) Fluorescence excitation spectra and light utiliation in two red tide dinoflagellates. Limnology and Oceanography
Vitenskapelig artikkel
Millie, D.; Schofield, O. M.; Kirkpatrick, G. J.; Johnsen, Geir; Tester, P. A.; Vinyard, B. T.. (1997) Phytoplankton pigments and absorption spectra as potential bio-markers for harmful algal blooms: A case study of the Florida red-tide dinoflagellat Gymnodinium breve. Limnology and Oceanography
Vitenskapelig artikkel
Grzymski, J.; Johnsen, Geir; Sakshaug, Egil. (1997) The significance of intracellular self-shading on the bio-optical properties of brown, red and green macroalgal species. Journal of Phycology
Vitenskapelig artikkel
Vernet, M.; Mitchell, B.G.; Sakshaug, Egil; Johnsen, Geir; Iturriaga, R.; Wassmann, P.. (1996) Evidence for a novel pigment with in vivo absorption maximum at 708 nm associated with Phaeocystis cf. pouchetii blooms. Marine Ecology Progress Series
Vitenskapelig artikkel
Schofield, O.; Prezelin, B. B.; Johnsen, Geir. (1996) Wavelength-dependency of maximum quantum yield of carbon fixation for two red tide dinoflagellates, Heterocapsa pygmaea and prorocentrum minimum. Journal of Phycology
Vitenskapelig artikkel
Johnsen, Geir; Sakshaug, Egil. (1996) Light harvesting in bloom-forming marine phytoplankton: Species-specifity and photoacclimation,. Scientia Marina
Vitenskapelig artikkel
Johnsen, Geir; Volent, Z; Tangen, K; Sakshaug, Egil. (1996) Time-series of potential toxic phytoplankton blooms in North European waters in 1993 using the SEAWATCH-Europe buoy system. EOS
Vitenskapelig artikkel
Vernet, M.; Mitchell, B. G.; Sakshaug, Egil; Johnsen, Geir; Iturriaga, R.; Wassmann, P.. (1996) Evidence for a novel pigment with in vivo absorption maximum at 708 nm associated with Phaeocystis sp. blooms. Marine Ecology Progress Series
Vitenskapelig artikkel
Millie, D; Shofield, O. M; Kirkpatrick, G. J; Tester, P. A; Johnsen, Geir. (1996) Using bio-optical characterisics as bio-markers for harmful algal blooms: A case study of the Florida red-tide dinoflagellate,. EOS
Vitenskapelig artikkel
Johnsen, Geir; Sakshaug, Egil. (1995) Light harvesting in bloom-forming marine phytoplankton: species-specificity and photoadaption. Scientia Marina
Vitenskapelig artikkel
Egeland, E.; Johnsen, Geir; Eikrem, W.; Liaaen-Jensen, S.; Throndsen, J.. (1995) The pigments of Bathycoccus prasinos. Journal of Phycology
Vitenskapelig artikkel
Jovine, R. V.; Johnsen, Geir; Prezelin, B. B.. (1995) Isolation of membrane bound chlorophyll a-chlorofhyll c binding light harvesting complexes from the dinoflagellates heterocapsa pygmaea and Prorocentrum minimum. Photosynthesis Research
Vitenskapelig artikkel
Johnsen, Geir; Nelson, N. B.; Jovine, R. V. M.; Prezelin, B. B.. (1994) Chromoprotein- and pigment-dependent modeling of spectral light absorption in two dinoflagellates, Prorocentrum minimum and Heterocapsa pygmaea. Marine Ecology Progress Series
Vitenskapelig artikkel
Jovine, R. V; Johnsen, Geir; Prezelin, B. B. (1994) Photoadaptation of Prorocentrum minimum and Heterocapsa pygmaea (Dinoflagellates): Chromoprotein changes and the consequenses for spectral absorption. EOS
Vitenskapelig artikkel
Jovine, R. V.; Schofield, O.; Johnsen, Geir; Prezelin, B. B.. (1994) Photoacclimatory differences in the light-harvesting complex of the bloom forming dinoflagellates Heterocapsa pygmaea and Prorocentrum minimum. Journal of Phycology
Vitenskapelig artikkel
Johnsen, Geir; Samset, O.; Granskog, L.; Sakshaug, Egil. (1994) In vivo absorption characteristics in 10 classes of phytoplankton: Taxonomic characteristics and responses to photoadaption by means of discriminant and HPLC analysis. Marine Ecology Progress Series
Vitenskapelig artikkel
Johnsen, Geir; Sakshaug, Egil. (1993) Bio-optical characteristics and photoadaptive responses in the toxic and bloomforming dinoflagellates Gyrodinium aureolum, Gymnodinium galatheanum two strains of Prorocentrum minium. Journal of Phycology
Vitenskapelig artikkel
Gilstad, Mona; Johnsen, Geir; Sakshaug, Egil. (1993) Photosynthetic parameters, pigment composition and respiration rates of the marine diatom Skeletonema costatum grown in continuous light and a 12:1 light-dark cycle. Journal of Plankton Research
Vitenskapelig artikkel
Volent, Zsolt; Johnsen, Geir. (1993) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a buoy. Underwater light measurements. Proceedings from International Symposium on high latitude optics.
Vitenskapelig artikkel
Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1992) Bio-optical characteristicts of phytoplankton in relation to remote sensing. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
Vitenskapelig artikkel
Volent, Zsolt; Johnsen, Geir. (1992) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a moored buoy. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
Vitenskapelig artikkel
Johnsen, Geir; Sakshaug, Egil; Vernet, Maria. (1992) Pigment composition, spectral characteriation and photosynthetic parameters in Chrysochromulina polylepis. Marine Ecology Progress Series
Vitenskapelig artikkel
Johnsen, Geir. (1991) Proceedings from a scientific working meeting. Fisken og Havet
Vitenskapelig artikkel
Johnsen, Geir; Hegseth, Else Nøst. (1991) Photoadaptation of sea-ice microalgae in the Barents Sea. Polar Biology
Vitenskapelig artikkel
Johnsen, Geir. (1991) Identification of Chrysochromulina leadbeateri by means of remote sensing. Fisken og Havet
Vitenskapelig artikkel
Sakshaug, Egil; Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1991) Identification of phytoplankton blooms by means of remote sensing. Environment Northern Seas
Vitenskapelig artikkel
Sakshaug, Egil; Johnsen, Geir; Andresen, Kjersti; Vernet, Maria. (1991) Modeling of light-dependent algal photosynthesis and growth: Experiments with the Barents Sea diatoms Thalassiosira nordensskioeldii and Chaetocero furcellatus. Deep-Sea Research Part II: Topical Studies in Oceanography
Vitenskapelig artikkel

Kunstneriske produksjoner

Snyder, Mike; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2021) “Into the dark” documentary by Mike Snyder following Jørgen Berge (UiT), Geir Johnsen (NTNU) and David McKee (Uni Strathclyde) during Polar Night marine ecology work. .
Film

Bøker

Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Polar night marine ecology - life and light in the dead of night. Springer Advances in Polar Ecology (0)
Vitenskapelig antologi/Konferanseserie
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2012) Phytoplankton Pigments: Characterization, Chemotaxonomy and Applications in Oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2012)
Vitenskapelig antologi/Konferanseserie
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Phytoplankton pigments : characterization, chemotaxonomy and applications in oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2011)
Vitenskapelig antologi/Konferanseserie
Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit M.. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
Fagbok
Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
Vitenskapelig antologi/Konferanseserie
Sakshaug, E.; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
Lærebok
Sakshaug, Egil; Johnsen, Geir. (2005) Algal cultures, Analogues of Blooms and Applications. Multi-Science Publishing Multi-Science Publishing
Vitenskapelig antologi/Konferanseserie
Syvertsen, E.; Hegseth, E; Johnsen, Geir; Sakshaug, Egil; Gulliksen, B; Lønne, O. J. (1992) Livet i isen (The life in the ice). In Økosystem Barentshavet. [Mangler utgivernavn]
Fagbok
Sakshaug, Egil; Kristiansen, S; Syvertsen, E; Eilertsen, H. C; Gilstad, M; Hegseth, E. N. (1992) Planktonalger (Phytoplankton). In Økosystem Barentshavet. [Mangler utgivernavn]
Fagbok

Del av bok/rapport

Zolich, Artur Piotr; Faltynkova, Andrea; Johnsen, Geir; Johansen, Tor Arne. (2022) Portable Catamaran Drone - an uncrewed sampling vehicle for micro-plastics and aquaculture research.
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Berge, Jørgen; Johnsen, Geir. (2020) Life and Light at the Dead of Night. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Johnsen, Geir; Zolich, Artur Piotr. (2020) Light in the Polar Night. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H.. (2020) Operative Habitat Mapping and Monitoring in the Polar Night. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Leu, Eva; Gradinger, Rolf. (2020) Marine Micro- and Macroalgae in the Polar Night. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Introduction. Springer
Innledning
Pavlov, Alexey K.; Leu, Eva; Hanelt, Dieter; Bartsch, Inka; Karsten, Ulf; Hudson, Stephen. (2019) The Underwater Light Climate in Kongsfjorden and Its Ecological Implications. Springer
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Zolich, Artur Piotr; De La Torre, Pedro R.; Rodwell, Shane; Geoffroy, Maxime; Johnsen, Geir; Berge, Jørgen. (2018) An ice-tethered buoy for fish and plankton research. IEEE conference proceedings
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Ludvigsen, Martin; Thorsnes, Terje; Hansen, Roy Edgar; Sørensen, Asgeir Johan; Johnsen, Geir; Lågstad, Petter Arthur. (2015) Underwater vehicles for environmental management in coastal areas. IEEE conference proceedings
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Ødegård, Øyvind; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan; Dukan, Fredrik. (2014) Managing data from multiple sensors in an interdisciplinary research cruise. Amsterdam University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Volent, Zsolt; Dierssen, Heidi; Pettersen, Ragnhild; Ardelan, Murat Van; Søreide, Fredrik. (2013) Underwater hyperspectral imagery to create biogeochemical maps of seafloor properties. Woodhead Publishing Limited
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Ludvigsen, Martin; Johnsen, Geir; Lågstad, Petter Arthur; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2013) Scientific operations combining ROV and AUV in the Trondheim Fjord. IEEE conference proceedings
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Brunet, Christophe; Johnsen, Geir; Lavaud, Johan; Roy, Suzanne. (2011) Pigments and photoacclimation processes. Cambridge University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Bricaud, Annick; Nelson, Norman; Prézelin, Barbara; Bidigare, Robert. (2011) In vivo bio-optical properties of phytoplankton pigments. Cambridge University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Moline, Mark; Pettersson, Lasse H.; Pinckney, J. L.; Pozdnyakov, Dmitry; Egeland, Einar Skarstad. (2011) Optical monitoring of phytoplankton bloom pigment signatures. Cambridge University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Llewellyn, Carole A.; Roy, Suzanne; Johnsen, Geir; Egeland, Einar Skarstad; Chauton, Matilde ; Hallegraeff, Gustaff. (2011) Perspectives on future directions. Cambridge University Press
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Preface. Cambridge University Press
Forord
Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Acknowledgements. Cambridge University Press
Annet
Johnsen, Geir; Volent, Z; Sakshaug, E.; Sigernes, Fred; Pettersson, L.H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, E.; Johnsen, Geir; Kristiansen, Svein; Quillfeldt, C.v.; Rey, F.; Slagstad, D.. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, E.; Johnsen, Geir; Volent, Z. (2009) Light. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Quillfeldt, C.v.; Hegseth, E.N.; Johnsen, Geir; Sakshaug, E.; Syvertsen, E.E.. (2009) Ice algae. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
von Quillfeldt, Cecilie H.; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik. (2009) Ice algae. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
von Quillfeldt, Cecilie; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik E.. (2009) Ice algae. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, Egil; Johnsen, Geir; Kristiansen, Svein; von Quillfeldt, Cecilie; Rey, Francisco; Slagstad, Dag. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, Egil; Johnsen, Geir; Volent, Z.. (2009) Light. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Volent, Zsolt; Sakshaug, Egil; Sigernes, Fred; Pettersson, Lasse H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Sakshaug, Egil; Johnsen, Geir. (2005) Absorption, fluorescence excitation and photoacclimation in phytoplankton. Multi-Science Publishing
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Samset, O.; Sakshaug, Egil. (1998) Bio-optical classification of potential harmful chlorophyll c -containing prymnesiophyte blooms in Scandinavian water.
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Volent, Z.; Tangen, K.; Sakshaug, Egil. (1997) Time series of harmful and benign phytoplankton blooms in northwest European waters using the Seawatch buoy system.
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
Johnsen, Geir; Volent, Z.; Tangen, K.; Sakshaug, Egil. (1997) Time series of harmful and benign phytoplankton blooms in northwest European waters using the Seawatch buoy system.
Vitenskapelig Kapittel/Artikkel/Konferanseartikkel

Rapport

Nøland, Annecken; Johnsen, Geir; Aberle-Malzahn, Nicole. (2022) Autonomous Underwater Vehicle (AUV) based study of zooplankton communities, using a silhouette camera and artificial intelligence. NTNU
Mastergradsoppgave
Johnsen, Geir; Aberle-Malzahn, Nicole; Fragoso, Glaucia; Thu, Maren. (2022) Phytoplankton Spring Bloom Mapping in Coastal Areas Using Autonomous Underwater Vehicle (AUV) and Optical Approaches. NTNU
Mastergradsoppgave
Nevstad, Malin Bø; Johnsen, Geir; Bakken, Torkild; Larsen, Martin Kvisvik; Mogstad, Aksel Alstad. (2022) Use of different imaging systems for ROV-based mapping of complex benthic habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Marnor, Camilla Mult; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Mapping distribution patterns of brittle stars using ROV-based imaging. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Bjerkvoll, Mikkel; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Aerial and underwater hyperspectral imagery for shallow benthic nature type mapping. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Søreng, Marte Opsahl; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad; Gryte, Kristoffer. (2022) Mapping of Zostera Habitat in the Sublittoral Zone using Underwater Hyperspectral Imaging and Unmanned Surface Vehicle. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Ringvold, Halldis; Johnsen, Geir; Andersen, Tom. (2021) Studies on Echinodermata from the NE Atlantic Ocean - Spatial distribution and abundance of Asteroidea, including taxonomic and molecular studies on Crossaster and Henricia genera - Value-chain results, including test fishery, biology, market and nutritional analysis on Parastichopus tremulus (Holothuroidea) from the Norwegian coast. Doktoravhandlinger ved NTNU (2021-254)
Doktorgradsavhandling
Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2021) Underwater hyperspectral imaging as a tool for benthic habitat mapping. Doktoravhandlinger ved NTNU (2021/271)
Doktorgradsavhandling
Graham, Lisa Kristine Hernandez; Johnsen, Geir; Christensen-Dalsgaard, Signe. (2019) A pilot study assessing drones for mapping and monitoring of European shags. Institutt for biologi, NTNU
Mastergradsoppgave
Fjærtoft, Kaja Lønne; Bakken, Torkild; Johnsen, Geir; Ludvigsen, Martin. (2018) Macroalgal detritus: Physical variables and impacts on the benthic macrofaunal community. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin; Hansen, Roy Edgar; Maarleveld, Thijs. (2018) Towards Autonomous Operations and Systems in Marine Archaeology. Doktoravhandlinger ved NTNU (IMT-12)
Doktorgradsavhandling
Strømsholm, Jørgen; Johnsen, Geir; Ludvigsen, Martin. (2018) Eyes beneath the surface - using a miniROV to reveal habitat and dietary choices of the European shag. NTNU MSc thesis
Mastergradsoppgave
Kauko, Hanna Maria; Johnsen, Geir; Assmy, Phillipp. (2018) Light response and acclimation of macroalgae in a changing Arctic. Doktoravhandlinger ved NTNU (2018)
Doktorgradsavhandling
Nornes, Stein Melvær; Sørensen, Asgeir Johan; Ludvigsen, Martin; Johnsen, Geir; Schjølberg, Ingrid; Ånonsen, Kjetil Bergh. (2018) Guidance and Control of Marine Robotics for Ocean Mapping and Monitoring. Doktoravhandlinger ved NTNU (2018:202)
Doktorgradsavhandling
Mynors, Julie; Johnsen, Geir; Wernand, Marcel; Volent, Zsolt. (2017) Ocean Colour and Phytoplankton Dynamics - An examination of the Forel-Ule scale in a modern context. NTNU Trondheim
Mastergradsoppgave
Kamilla, Sporsheim; Sporsheim, Kamilla; Johnsen, Geir; Reitan, Kjell Inge; Evertsen, Antii Jussi. (2017) Astaxanthin as a biomarker for fish feed loading in the marine ecosystem. NTNU, Trondheim
Mastergradsoppgave
Kjeken, John; Johnsen, Geir; Ludvigsen, Martin; Thorsnes, Terje; Lågstad, Petter Arthur. (2017) The growth of benthic organisms in a dumping ground for military bombs and munitions. NTNU, Trondheim
Mastergradsoppgave
Johnsen, Geir; Sandbu, Marthe; Assmy, Philipp. (2017) High Arctic Sea-Ice Algae: The Use of Rapid Light Curves to Assess Photosynthetic Performance of Different Ice-Algal Communities. Master science NTNU
Mastergradsoppgave
Andersson, Ingvild Henriette Kristin; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin. (2017) Bio-optical diversity on cold water coral habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Alvsvåg, Dora Marie; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Berge, Jørgen. (2017) Mapping of a seagrass habitat in Hopavågen, Sør-Trøndelag, with the use of an Autonomous Surface Vehicle combined with optical techniques. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Paulsen, Emil; Bakken, Torkild; Ramirez-Llodra, Eva; Johnsen, Geir. (2017) Community structure and biodiversity of the benthic megafauna at the inactive hydrothermal site Mohn's Treasure, on the Mohn's Ridge, Arctic Mid-Ocean Ridge (AMOR) . Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
Mastergradsoppgave
Jakobsen, June; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Karlsen, Svein. (2016) The Tautra Cold-Water Coral Reef - Mapping and describing the biodiversity of a cold-water coral reef ecosystem in the Trondheimsfjord by use of multi-beam echo sounding and video mounted on a remotely operated vehicle. NTNU
Mastergradsoppgave
Håpnes, Sverre Julian; Johnsen, Geir; Ludvigsen, Martin; Lågstad, Petter Arthur. (2016) Mapping of demersal fish and benthos by AUV equipped with optical and acoustic imagers at 600 m depth in Trondheimsfjorden. NTNU MSc
Mastergradsoppgave
Liefmann, Stepha

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Geir Johnsen

Geir Johnsen

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