A5041923050- Marine and coastal ecosystems
- Marine and fisheries research
- Marine Biology and Ecology Research
- Isotope Analysis in Ecology
- Marine Bivalve and Aquaculture Studies
- Aquaculture Nutrition and Growth
- Ocean Acidification Effects and Responses
- Fish Ecology and Management Studies
- Oceanographic and Atmospheric Processes
- Microplastics and Plastic Pollution
- Marine and environmental studies
- Mercury impact and mitigation studies
- Aquatic Ecosystems and Phytoplankton Dynamics
- Environmental Toxicology and Ecotoxicology
- Diatoms and Algae Research
- Microbial Community Ecology and Physiology
- Marine Biology and Environmental Chemistry
- Toxic Organic Pollutants Impact
- Food Industry and Aquatic Biology
- Protein Hydrolysis and Bioactive Peptides
- Geology and Paleoclimatology Research
- Arctic and Antarctic ice dynamics
- Edible Oils Quality and Analysis
- Avian ecology and behavior
- Nuclear and radioactivity studies
Technical University of Denmark
2015-2025
University of Copenhagen
2024
Marine and Freshwater Research Institute
2024
Aarhus University
2024
Norwegian Institute of Marine Research
2024
University of Cape Coast
2020
Danish Centre for Marine Research
1998-2007
University of Connecticut
1998
State University of New York
1990-1996
Stony Brook University
1993-1996
Significance Every autumn across the North Atlantic, large numbers of zooplankton copepods migrate from surface waters into ocean's interior to hibernate at depths 600–1,400 m. Through this migration, they actively transport lipid carbon below permanent thermocline, where it is metabolized a rate comparable delivered by sinking detritus. This “lipid pump” has not been included in previous estimates deep-ocean sequestration, which are based on either measurements fluxes detritus, or new...
Here we present a new, pan-Atlantic compilation and analysis of data on Calanus finmarchicus abundance, demography, dormancy, egg production mortality in relation to basin-scale patterns temperature, phytoplankton biomass, circulation other environmental characteristics the context understanding factors determining distribution abundance C. across its North Atlantic habitat. A number themes emerge: (1) south-to-north transport plankton northeast contrasts with north-to-south western...
Exploring climate and anthropogenic impacts on marine ecosystems requires an understanding of how trophic components interact. However, integrative end-to-end ecosystem studies (experimental and/or modelling) are rare. Experimental investigations often concentrate a particular group or individual species within level, while tropho-dynamic field typically employ either bottom-up approach concentrating the phytoplankton community top-down fish community. Likewise emphasis modelling is usually...
AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 31:267-278 (2003) - doi:10.3354/ame031267 Effect of heterotrophic versus autotrophic food on feeding and reproduction calanoid copepod Acartia tonsa: relationship with prey fatty acid composition Elisabetta Broglio1,*, Sigrún H. Jónasdóttir2, Albert Calbet1, Hans Jakobsen2,3, Enric Saiz1 1Departament de Biologia Marina i...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 119:87-98 (1995) - doi:10.3354/meps119087 Copepod egg production in Long Island Sound, USA, as a function of chemical composition seston Jónasdóttir, S. H., Fields, D., Pantoja, The effect on egg-production rates (Er: eggs female-1 d-1) copepods Acartia hudsonica Pinhey and Temora longicornis (Müller) was...
Abstract Data from plankton net and Optical Plankton Counter sampling during 12 winter cruises between 1994 2002 have been used to derive a multi-annual composite 3-D distribution of the abundance over-wintering Calanus finmarchicus in swath across North Atlantic Labrador Norway. Dense concentrations occurred Sea, northern Irminger Basin, Iceland eastern Norwegian Faroe–Shetland Channel, Trench Sea. A model buoyancy regulation C. was lipid content implied by situ temperature salinity at...
We developed new perspectives to identify important questions and propose approaches for future research on marine food web lipids. They were related (i) structure function of lipids, (ii) lipid changes during critical life phases, (iii) trophic marker (iv) potential impact climate change. The first addresses the role lipids in membranes, storage buoyancy with following key question: How are properties membranes deposits affected by various types lipids? second deals importance reproduction,...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 382:139-150 (2009) - DOI: https://doi.org/10.3354/meps07985 Assessing role of food quality in production and hatching Temora longicornis eggs Sigrún Huld Jónasdóttir1,*, André W. Visser1, Carsten Jespersen2 1Technical University Denmark, National Institute Aquatic Resources (DTU-Aqua), Kavalergaarden 6, 2920...
We investigated the effect of suspended sediments on vital rates copepods Calanus finmarchicus, Pseudocalanus sp. and Metridia longa in a Greenland sub-Arctic fjord. The fjord had gradient particulate matter (SPM) with high concentrations (>50 mg L−1) inner due to glacial melt water runoff. Laboratory experiments showed that when feeding diatom Thalassiosira weissflogii specific ingestion were low at sediment for C. finmarchicus (>20 L−1), while no was found M. longa. For relatively constant...
Abstract Every year, large numbers of zooplankton migrate from the surface ocean to depths 500–2000 m hibernate. Through this migration, they actively transport organic carbon deep ocean, where it is used fuel metabolic needs. This active thought be highly efficient, as metabolized by copepods directly injected into ocean's interior. The significance process in view global cycling remains an open question. Here, we focus on five representative, diapausing copepod species ( Calanus...
Lipid class contents and composition of the copepodite stage CV adult female Calanus finmarchicus were measured from autumn to spring along a transect crossing Faroe–Shetland Channel. The data give detailed vertical resolution lipid content C. fin‐marchicus before, during after time diapause. In deep water, where was in diapause, wax ester (WE) did not change between with exception that females, which showed significant decrease by March. concentrations lipids lower more variable both...
The copepod Calanus finmarchicus remains in diapause for up to 5 months the cold (<0.5°C) deep (>700 m) waters of Faroe–Shetland Channel north‐western approaches North Sea. While diapause, C. has a high lipid content, 76% dry weight, mostly form wax esters. question we address here is how copepods with such content buoyant lipids can remain at depth an extended period time? corollary this hinders and/or assists their seasonal vertical migration? Part answer due physical properties...
The population of Calanus finmarchicus in the North Sea is replenished each spring by invasion from an overwintering stock located beyond shelf edge. A combination field observations, statistical analysis Continuous Plankton Recorder (CPR) data, and particle tracking model simulations, was used to investigate processes involved cross‐shelf invasion. results showed that main source animals entering at depths greater than 600 m Faroe–Shetland Channel, where concentrations up 620 −3 are found...
Physiological characteristics (egg production, lipid content and gonad development stage) of Calanus finmarchicus were examined on five cruises in the north‐east Atlantic carried out between months October to March years 1993–95 related phytoplankton food availability. Appreciable egg production rates only recorded March. Published values for maximum water volume filtered daily by individual females standing stock (estimated from chlorophyll concentration) are used argue that ingestion...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 381:249-258 (2009) - DOI: https://doi.org/10.3354/meps07960 Recruitment of lesser sandeel Ammodytes marinus in relation density dependence and zooplankton composition Mikael van Deurs1,*, Ralf Hal2, Maciej T. Tomczak1, Sigrún H. Jónasdóttir1, Per Dolmer1 1National Institute Aquatic Resources, Technical...
We studied the response in development times of Calanus finmarchicus and helgolandicus to changes temperature food conditions. Grazing experiments were performed at different temperatures for both species, results implemented a stage‐resolved zooplankton population model that predicted from biomass increments controlled by ingestion metabolic losses. Predictions validated against data literature, show C. develops faster than below 11°C slower above. The relative rates species are related...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 151:1-10 (1997) - doi:10.3354/meps151001 Nutritional quality of two cyanobacteria: How rich is 'poor' food? Schmidt K, Jónasdóttir SH Cyanobacteria have often been described be nutritionally inadequate and interfere with zooplankton feeding. In laboratory experiments we offered 2 cyanobacteria, a unicellular...
Feeding and fecundity of two calanoid copepod species ( Acartia bifilosa Eurytemora affinis ) were studied in a food assemblage dominated by toxic cyanobacteria, to reveal whether mesozooplankton are able obtain sufficient good quality different phases cyanobacteria bloom. Bloom conditions simulated mesocosm adding high concentration cultured hepatotoxic Nodularia spumigena 100 mm filtered natural sea water. This seston was fed copepods at days 1, 7, 14 from the start experiment, when it...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 134:247-263 (1996) - doi:10.3354/meps134247 Food web interactions in plankton of Long Island bays, with preliminary observations on brown tide effects Lonsdale DJ, Cosper EM, Kim WS, Doall M, Divadeenam A, Jonasdottir SH We examined relative importance phytoplankton and ciliates as prey for metazoan...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 286:293-305 (2005) - doi:10.3354/meps286293 Colloquium on diatom-copepod interactions G. A. Paffenhöfer1,*,+, ♦, Ianora2,+, Miralto2,+, J. T. Turner3, S. Kleppel4, M. Ribera d'Alcalà2, R. Casotti2,♦, Caldwell5,♦, Pohnert6,♦, Fontana7,♦,D. Müller-Navarra8,♦, Jónasdóttir9,♦, V. Armbrust10,#,U. Båmstedt11,#,...
Abstract The boreal copepod Calanus finmarchicus accumulates lipid reserves during summer feeding in surface ocean waters, which enable it to stay at depth and survive famine overwintering. Respiration of lipids prolonged overwintering depths (> 1000 m some areas) has been shown result a net sequestration carbon into the deep ocean: so‐called “lipid pump.” Here, we provide comprehensive synthesis geographic vertical variations content animals across Subpolar Eastern North Atlantic and, on...
Spatial and seasonal egg production rates (Er) hatching success in the copepods Calanus finmarchicus helgolandicus were measured North Sea from March to September. Food availability was monitored by chlorophyll protist concentrations three size fractions of seston fatty acids. Seasonal spatial distribution differed between species. found only offshore 50-m isobath, with decreasing Er (37–28 eggs female−1 day−1) July. had two abundance peaks, spring autumn, a low May during which time highest...