A5065935244- Aquaculture Nutrition and Growth
- Marine Bivalve and Aquaculture Studies
- Marine and fisheries research
- Isotope Analysis in Ecology
- Fish Ecology and Management Studies
- Marine and coastal ecosystems
- Marine Biology and Ecology Research
- Ocean Acidification Effects and Responses
- Reproductive biology and impacts on aquatic species
- Aquatic Ecosystems and Phytoplankton Dynamics
- Fish Biology and Ecology Studies
- Crustacean biology and ecology
- Marine Invertebrate Physiology and Ecology
- Insect Utilization and Effects
- Identification and Quantification in Food
- Environmental Toxicology and Ecotoxicology
- Marine and environmental studies
- Parasite Biology and Host Interactions
- Physiological and biochemical adaptations
- Marine Ecology and Invasive Species
- Environmental DNA in Biodiversity Studies
- Oceanographic and Atmospheric Processes
- Microbial Community Ecology and Physiology
- Coral and Marine Ecosystems Studies
- Microplastics and Plastic Pollution
Universität Hamburg
2023-2025
SINTEF
2016-2025
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2008-2018
University of Bremen
2018
Sultan Qaboos University
2013-2016
Max Planck Society
2013
Helmholtz-Zentrum Hereon
2011-2012
Analyzing one of the most extensive long‐term data series in North Sea, Helgoland Roads time series, we investigated changes factors that potentially drive phytoplankton bloom dynamics German Bight. We compared these with spring phenology. combined zooplankton, nutrient, weather, and to analyze whether there has been a shift trophic interactions Sea affecting timing. The potential influence temperature, mean increase 1.5°C, was investigated. showed Bight around is highly dynamic system...
We investigated whether nutrient limitations of primary producers act upward through food webs only in terms density effects or if there is a second pathway for limitation signals channelled to higher trophic levels. used tritrophic chains assess the nutrient‐limited phytoplankters (the cryptophyte Rhodomonas salina ) on herbivorous zooplankters calanoid copepod Acartia tonsa and finally zooplanktivores (larval herring Clupea harengus living herbivores. The producers’ quality had significant...
In their seminal paper, Goldman et al. suggested that phytoplankton close to maximum growth rate attains a restricted optimal N : P ratio the Redfield of molar = 16. Recently, presence such global attractor for stoichiometry has been questioned in models and empirical analyses. As chemical composition is major importance our understanding elemental cycles biogeochemical transformations, we assembled 55 data sets biomass ratios meta‐analysis testing (1) whether converges at high rates, (2)...
Herbivores are generally faced with a plethora of resources which differ in quality. Therefore, they should be able to select foods most closely match their metabolic needs. Here, we tested the hypothesis that copepods species Acartia tonsa prey cells based on quality differences within species. We assessed age‐specific variation feeding behaviour and evaluated potential consequences such for nutrient cycles. Nauplii (young) stages characterized by low nitrogen phosphorus (N:P) ratio body...
Abstract It is a well accepted fact that nutrient limitation of plants affects the growth and survival herbivores, generally leading to lower performance herbivores feeding on stressed plants. The effect plants' growing conditions predatory organisms, one trophic level up, has been much less studied, there general consensus such effects would be small as often show relatively strong homeostasis with respect their content. Here, we challenge this view, from several examples despite buffer...
The polychaete Hediste diversicolor is known to recycle side streams from aquaculture and biogas production. We conducted a feeding experiment evaluate whether rearing temperature or mixtures of these two enhances biomass production fatty acid composition. reared H. along 5-temperature gradient ranging 5.8 °C 17.1 4-step form 100% sludge solid digestate. Formulated fish feed served as control diet. Polychaetes increased growth rate with increasing temperature, 0.01 at 0.14 °C, while survival...
Recruitment patterns of Baltic Sea sprat (Sprattus sprattus) were correlated to time series (i) month- and depth-specific temperature conditions (ii) larval drift inferred from long-term Lagrangian particle simulations. From the latter, we derived an index that likely reflected variable degree annual transport central, deep spawning basins shallow coastal areas Sea. The was significantly (P < 0.001) recruitment success explained, together with stock biomass, 82% overall variability...
Stoichiometric homeostasis is the ability of an organism to keep its body chemical composition constant, despite varying inputs. therefore constrains metabolic needs consumers which in turn often feed on resources not matching these requirements. In a broader context, also relates capacity maintain other biological parameters (e.g. temperature) at constant level over ambient environmental variations. Unfortunately, there are discrepancies literature and ecological physiological definitions...
Herbivores regularly face imbalanced diets on a variety of timescales. They respond to such with reductions in growth and reproduction. The effect exposure time poor quality recovery potential herbivores has yet not been intensively studied. In order investigate the response nutritional condition phosphorus limited algal food, we fed copepod Acartia tonsa autotrophic flagellate Rhodomonas salina , which was cultured towards high low content. To test duration P food growth, also switched...
Abstract. Impacts of ocean acidification (OA) on marine biota have been observed in a wide range systems. We used mesocosm approach to study the response high Arctic coastal microzooplankton community during post-bloom period Kongsfjorden (Svalbard) direct and indirect effects pCO2/low pH. found almost no OA composition diversity. Both relative shares ciliates heterotrophic dinoflagellates as well taxonomic remained unaffected by changes pCO2/pH. Although different pCO2 treatments affected...
Abstract Aim Invasive species are of increasing global concern. Nevertheless, the mechanisms driving further distribution after initial establishment non‐native remain largely unresolved, especially in marine systems. Ocean currents can be a major driver governing range occupancy, but this has not been accounted for most invasion ecology studies so far. We investigate how well areas interconnected to later occupancy regions test potential role ocean secondary spread dynamics order infer...
Integrated multi-trophic aquaculture (IMTA) has the potential of reducing open-cage fish farming impacts on environment while also introducing new value chains. The aim this study was to investigate growth and composition kelp Saccharina latissima in salmon-driven IMTA, assess spatial extent influence salmon derived nitrogen order evaluate upscaling for IMTA. S. cultivated 100, 200 1,000 m east west a 5,000 tonnes farm Western Norway from February September 2013. proportion available showed...
Increased aquaculture production will result in increased amounts of waste produced, and these wastes are highly underexploited. Polychaetes might effectively consume such transfer them into compounds as marine proteins lipids. In our study, growth nutritional composition the polychaete worm Hediste diversicolor (O.F. Müller, 1776) were analyzed to evaluate i) capability H. utilize from land-based salmon smolt farms for ii) cultivated on waste. The worms fed iso‑carbonic diets comprised fish...
Ocean acidification may affect zooplankton directly by decreasing in pH, as well indirectly via trophic pathways, where changes carbon availability or pH effects on primary producers cascade up the food web thereby altering ecosystem functioning and community composition. Here, we present results from a mesocosm experiment carried out during 113 days Gullmar Fjord, Skagerrak coast of Sweden, studying plankton responses to predicted end-of-century pCO2 levels. We did not observe any effect...
Omega-3 ( ω 3 or n -3) long-chain polyunsaturated fatty acids (PUFA), including eicosapentaenoic acid and docosahexaenoic (DHA), play physiologically important roles in vertebrates. These compounds have long been believed to originated almost exclusively from aquatic (mostly marine) single-cell organisms. Yet, a recent study has discovered that many invertebrates possess type of enzymes called methyl-end desaturases x ) enables them endogenously produce -3 PUFA could make significant...
Introduction Sustainable growth of the salmon aquaculture industry is highly dependent on availability new feed resources as well improved management and utilization waste streams from production. Polychaetes are capable recapturing recycling valuable biomolecules contained in sludge at same time constitute a possible resource for aquafeeds. Material methods In this study, potential Hediste diversicolor (OF Müller, 1776) to recover nutrients energy was evaluated. Hereby, effect two different...
ABSTRACT Aquaculture farming discharges large volumes of fish sludge, consisting particulate organic matter from feed spill and feces. Fish sludge land‐based salmonid aquaculture systems can potentially be used to low‐trophic species such as marine polychaetes insects. Further use these invertebrates may provide a more sustainable chain. However, food security must not compromise or safety. The is currently permitted in the European Union (EU). A regulatory assessment that considers...
Invertebrate herbivores are often faced with food of different quality, affecting growth, and reproductive rates. Temperature also has a strong influence on these rates, but how temperature quality interact is largely unknown. We investigated the interaction between developmental rates keystone plankton herbivore, calanoid copepod Acartia tonsa. fed along gradient five qualities from phosphorus-limited to phosphorus-replete algae, exposing them eight temperatures 8°C 22°C in full factorial...