Levels of Polybrominated Diphenyl Ether (PBDE) Flame Retardants in Animals Representing Different Trophic Levels of the North Sea Food Web

2002 ◽  
Vol 36 (19) ◽  
pp. 4025-4032 ◽  
Author(s):  
Jan P. Boon ◽  
Wilma E. Lewis ◽  
Michael R. Tjoen-A-Choy ◽  
Colin R. Allchin ◽  
Robin J. Law ◽  
...  
Keyword(s):  
Food Web ◽  
North Sea ◽  
Flame Retardants ◽  
Diphenyl Ether ◽  
Polybrominated Diphenyl Ether ◽  
Trophic Levels ◽  
The North ◽  
The North Sea

scholarly journals An approach for coupling higher and lower levels in marine ecosystem models and its application to the North Sea

2015 ◽  
Vol 8 (7) ◽  
pp. 5577-5618 ◽  
Author(s):  
J. A. Beecham ◽  
J. Bruggeman ◽  
J. Aldridge ◽  
S. Mackinson
Keyword(s):  
Environmental Change ◽  
Food Web ◽  
North Sea ◽  
Trophic Level ◽  
Coupled Model ◽  
Trophic Levels ◽  
Biogeochemical Model ◽  
The North ◽  
The North Sea

Abstract. End to end modelling is an attractive and rapidly developing approach to solve developing strategies in marine systems science and management. However problems remain in the area of data matching and sub-model compatibility. A mechanism and novel interfacing system (Couplerlib) is presented whereby a physical/biogeochemical model (GOTM-ERSEM) that predicts dynamics of the lower trophic level (LTL) organisms in marine ecosystems is coupled to a dynamic ecosystem model (Ecosim) that predicts food-web interactions among higher trophic level (HTL) organisms. Coupling is achieved by means of a bespoke interface which handles the system incompatibilities between the models and a more generic Couplerlib library which uses metadata descriptions in extensible mark-up language (XML) to marshal data between groups, paying attention to functional group mappings and compatibility of units between models. In addition, within Couplerlib, models can be coupled across networks by means of socket mechanisms. As a demonstration of this approach, a food web model (Ecopath with Ecosim, EwE) and a physical/biogeochemical model (GOTM-ERSEM) representing the North Sea ecosystem were joined with Couplerlib. The output from GOTM-ERSEM varies between years dependent on oceanographic and meteorological conditions. Although inter-annual variability was clearly present, there was always the tendency for an annual cycle consisting of a peak of diatoms in spring, followed by (less nutritious) flagellates and dinoflagellates through the summer resulting in an early summer peak in the mesozooplankton biomass. Pelagic productivity, predicted by the LTL model, was highly seasonal with little winter food for the higher trophic levels. The Ecosim model was originally based on the assumption of constant annual inputs and, consequently, when coupled, pelagic species suffered population loss over the winter months. By contrast, benthic populations were more stable (although the benthic linkage modelled was purely at the detritus level). The coupled model was used to examine long term effects of environmental change, and showed the system to be nutrient limited, relatively unaffected by forecast climate change, especially in the benthos. The stability of an Ecosim formulation for large higher tropic level food webs is discussed and it is concluded that this kind of coupled model formulation is better for examining the effects of long term environmental change than short term perturbations.

A Modular Approach for Modelling of the North Sea Ecosystem

1991 ◽  
Vol 24 (10) ◽  
pp. 1-8 ◽  
Author(s):  
A. Malmgren-Hansen ◽  
J. W. Baretta ◽  
P. Ruardij
Keyword(s):  
Food Web ◽  
North Sea ◽  
Algal Growth ◽  
Ecosystem Model ◽  
Trophic Levels ◽  
Basic Knowledge ◽  
Modular Approach ◽  
The North ◽  
The North Sea

A modular approach for generating an ecosystem model for the North Sea is presented. The model structure consists of modules describing physical, chemical and biological processes. The modular approach is selected to facilitate stepwise improvements in the total ecosystem model by replacing existing modules with improved modules being developed. The modules constituting the pelagic ecosystem describe the biological and chemical dynamics of particle production and dissolution simulating the flux of carbon and nutrients (N, P, Si) through the food web. This might be done as a suite of submodules based on functional groups of organisms or as modules describing the different trophic levels based on size distributions. Algal growth is dependent on cellular content of the limiting nutrient, or on net photosynthesis, whichever is the most restricting, allowing for “luxury uptake” of nutrients which may be stored for subsequent periods of shortage. The role of bacteria and other microorganisms is emphasized in recognition of the importance of the “microbial loop”. The Zooplankton module describes prey ingestion in terms of feeding behaviour and the partitioning of ingested carbon, nitrogen and phosphorus into growth and reproduction and the losses through respiration, excretion and defecation. The benthic modules concentrate on describing the small food web, since benthic biological activity in terms of carbon flow, as well as mineralization, are often dominated by micro- and meiofauna in the generally soft sediments of the North Sea. Macrobenthos are described as being a major link between the benthic small food web and higher trophic levels in the ecosystem. Higher trophic levels are described in separate modules taking into account in principle the role of fish, mammals and seabirds. Nutrient cycling is described, focusing on the identification and conceptual modelling of the chemical processes and mechanisms in order to describe the relationships between the biology of the North Sea and the nutrient chemistry. This represents a first step towards forecasting the response of the system to long-term changes due to e.g. eutrophication. The modelling of the nutrient sediment-water interaction emphasizes the role of sedimentation of particulates and the regeneration of inorganic components to the water column. This totally modular concept of the North Sea ecosystem model reflects the authors' view on the present state of the North Sea, the basic knowledge about ecosystem behaviour and a way of creating models as a tool for better understanding of the ecosystem and how man affects the North Sea environment.

scholarly journals Metabarcoding reveals different zooplankton communities in northern and southern areas of the North Sea

2020 ◽  
Author(s):  
Jan Niklas Macher ◽  
Berry B. van der Hoorn ◽  
Katja T. C. A. Peijnenburg ◽  
Lodewijk van Walraven ◽  
Willem Renema
Keyword(s):  
North Sea ◽  
Zooplankton Community ◽  
Taxonomic Diversity ◽  
Molecular Techniques ◽  
Trophic Levels ◽  
List Type ◽  
The North ◽  
Shelf Sea ◽  
The North Sea ◽  
Zooplankton Communities

AbstractZooplankton are key players in marine ecosystems, linking primary production to higher trophic levels. The high abundance and high taxonomic diversity renders zooplankton ideal for biodiversity monitoring. However, taxonomic identification of the zooplankton assemblage is challenging due to its high diversity, subtle morphological differences and the presence of many meroplanktonic species, especially in coastal seas. Molecular techniques such as metabarcoding can help with rapid processing and identification of taxa in complex samples, and are therefore promising tools for identifying zooplankton communities. In this study, we applied metabarcoding of the mitochondrial cytochrome c oxidase I gene to zooplankton samples collected along a latitudinal transect in the North Sea, a shelf sea of the Atlantic Ocean. Northern regions of the North Sea are influenced by inflow of oceanic Atlantic waters, whereas the southern parts are characterised by more coastal waters. Our metabarcoding results indicated strong differences in zooplankton community composition between northern and southern areas of the North Sea, particularly in the classes Copepoda, Actinopterygii (ray-finned fishes) and Polychaeta. We compared these results to the known distributions of species reported in previous studies, and by comparing the abundance of copepods to data obtained from the Continuous Plankton Recorder (CPR). We found that our metabarcoding results are mostly congruent with the reported distribution and abundance patterns of zooplankton species in the North Sea. Our results highlight the power of metabarcoding to rapidly assess complex zooplankton samples, and we suggest that the technique could be used in future monitoring campaigns and biodiversity assessments.HighlightsZooplankton communities are different in northern and southern areas of the North SeaMetabarcoding results are consistent with known species distributions and abundanceMetabarcoding allows for fast identification of meroplanktonic species

scholarly journals Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s

2005 ◽  
Vol 62 (7) ◽  
pp. 1205-1215 ◽  
Author(s):  
J. Alheit ◽  
C. Möllmann ◽  
J. Dutz ◽  
G. Kornilovs ◽  
P. Loewe ◽  
...  
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Climatic Variability ◽  
Regime Shifts ◽  
Trophic Levels ◽  
Copepod Species ◽  
The North ◽  
The North Sea ◽  
The North Atlantic ◽  
Low Levels

Abstract The index of the North Atlantic Oscillation, the dominant mode of climatic variability in the North Atlantic region, changed in the late 1980s (1987–1989) from a negative to a positive phase. This led to regime shifts in the ecology of the North Sea (NS) and the central Baltic Sea (CBS), which involved all trophic levels in the pelagial of these two neighbouring continental shelf seas. Increasing air and sea surface temperatures, which affected critical physical and biological processes, were the main direct and indirect driving forces. After 1987, phytoplankton biomass in both systems increased and the growing season was extended. The composition of phyto- and zooplankton communities in both seas changed conspicuously, e.g. dinoflagellate abundance increased and diatom abundance decreased in the CBS. Key copepod species that are essential in fish diets experienced pronounced changes in biomass. Abundance of Calanus finmarchicus (NS) and Pseudocalanus sp. (CBS) fell to low levels, whereas C. helgolandicus (NS) and Temora longicornis and Acartia spp. (CBS) were persistently abundant. These changes in biomass of different copepod species had dramatic consequences on biomass, fisheries, and landings of key fish species: North Sea cod declined, cod in the CBS remained at low levels, and CBS sprat reached unprecedented high biomass levels resulting in high yields. The synchronous regime shifts in NS and CBS resulted in profound changes in both marine ecosystems. However, the reaction of fish populations to the bottom-up mechanisms caused by the same climatic shift was very different for the three fish stocks.

Feeding, Growth and Reproduction of the Marine Planktonic Copepod Pseudo-Calanus Elongatus Boeck

1976 ◽  
Vol 56 (2) ◽  
pp. 327-344 ◽  
Author(s):  
G.-A. Paffenhöfer ◽  
R. P. Harris
Keyword(s):  
Food Web ◽  
North Sea ◽  
Calanoid Copepods ◽  
Small Copepod ◽  
The North ◽  
Controlled Conditions ◽  
Food Concentrations ◽  
Food Species ◽  
The North Sea ◽  
Growth And Reproduction

INTRODUCTIONThe development of techniques to culture calanoid copepods over multiple generations in the laboratory has resulted in considerable advances in knowledge about a group of animals of major importance in the marine food web. A series of extensive studies have been made of two species of large calanoids, Calanus helgolandicus (Claus) (Mullin & Brooks, 1967, 1970a, 1970b; Paffenhöfer, 1970, 1971, 1976a, 1976b), and Rhincalanus nasutus Giesbrecht (Mullin & Brooks, 1967, 1970a, 1970b). Feeding, growth, and reproduction have been studied under controlled conditions, using different temperatures, food species, and food concentrations. Some of the information gained in these studies has been incorporated into a simulation model of the planktonic ecosystem of the North Sea (Steele, 1974). However, in the North Sea and in many other sea areas species of small copepod probably form an important component of the food web. Little information is available on the quantitative biology of these small copepods under controlled conditions.

scholarly journals Shifts in spawning phenology of cod linked to rising sea temperatures

2017 ◽  
Vol 74 (6) ◽  
pp. 1561-1573 ◽  
Author(s):  
Kate McQueen ◽  
C. Tara Marshall
Keyword(s):  
Climate Change ◽  
North Sea ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Size Structure ◽  
Gonadal Development ◽  
Trophic Levels ◽  
Irish Sea ◽  
The North ◽  
The North Sea

AbstractWarming temperatures caused by climate change have the potential to impact spawning phenology of temperate marine fish as some species have temperature-dependent gonadal development. Inter-annual variation in the timing of Atlantic cod (Gadus morhua) spawning in the northern North Sea, central North Sea and Irish Sea was estimated by calculating an annual peak roe month (PRM) from records of roe landings spanning the last three decades. A trend towards earlier PRM was found in all three regions, with estimates of shifts in PRM ranging from 0.9 to 2.4 weeks per decade. Temperatures experienced by cod during early vitellogenesis correlated negatively with PRM, suggesting that rising sea temperatures have contributed to a shift in spawning phenology. A concurrent reduction in the mean size of spawning females excluded the possibility that earlier spawning was due to a shift in size structure towards larger individuals, as large cod spawn earlier than smaller-sized individuals in the North Sea. Further research into the effects of climate change on the phenology of different trophic levels within the North Sea ecosystem should be undertaken to determine whether climate change-induced shifts in spawning phenology will result in a temporal mismatch between cod larvae and their planktonic prey.

Organophosphorus flame retardants and plasticizers in the atmosphere of the North Sea

2011 ◽  
Vol 159 (12) ◽  
pp. 3660-3665 ◽  
Author(s):  
Axel Möller ◽  
Zhiyong Xie ◽  
Armando Caba ◽  
Renate Sturm ◽  
Ralf Ebinghaus
Keyword(s):  
North Sea ◽  
Flame Retardants ◽  
The North ◽  
The North Sea ◽  
Organophosphorus Flame Retardants

scholarly journals Why do jellyfish bloom in Norwegian waters and what can be done to recover the ecosystems in the North Sea and on the Norwegian coast?

2017 ◽  
Author(s):  
Johannes Hamre
Keyword(s):  
North Sea ◽  
West Coast ◽  
Trophic Levels ◽  
The West ◽  
Fish Stocks ◽  
Norwegian Coast ◽  
The North ◽  
Key Species ◽  
Wide Range ◽  
The North Sea

The ecosystems with their relationships between fish species and stocks, have been established by evolution for millions of years, but during the last 50 years, the ecosystems in the North Sea and along the Norwegian coast have been changed fundamentally by fisheries. The North Sea mackerel stock has been depleted and its feeding grounds have been invaded by the Western mackerel which spawns west of Ireland. This stock is now very rich in numbers and occupies the North Sea, the Norwegian Sea and the western Barents Sea. If the trend continues, mackerel may outcompete many of the other fish stocks in the area. Traditionally and until the beginning of the 1970s, there was a large stock of sandeel spawning in the North Sea and on the Norwegian coast. Sandeel juveniles was an important food source for a wide range of species, including sea mammals and birds. The fact that this stock has also been overfished, may explain many changes observed in the ecosystem on the west coast of Norway, for example a large reduction in the populations of sea birds. There are several instances where ecosystems shift to sustain jellyfish blooms in response to depletion of forage fish stocks. This was registered in Namibia in the 1990’s, where the pilchard stock was decimated and the biomass of jellyfish soon became overwhelming. On the west-coast of Norway, there are now frequent blooms of jellyfish, yet another indication that a controlling factor is missing in the system, in this case sandeel, which is a key species in the transfer of nutrients from zooplankton to higher trophic levels in the area. In this paper, I give a description of the situation and some suggested measures that should be taken in fisheries management.

Large-scale responses of nematode communities to chronic otter-trawl disturbance

2008 ◽  
Vol 65 (4) ◽  
pp. 723-732 ◽  
Author(s):  
Hilmar Hinz ◽  
Jan G Hiddink ◽  
James Forde ◽  
Michel J Kaiser
Keyword(s):  
Food Web ◽  
North Sea ◽  
Large Scale ◽  
Life Cycles ◽  
Irish Sea ◽  
Otter Trawl ◽  
Food Web Structure ◽  
Nematode Communities ◽  
The North ◽  
The North Sea

Nematodes, because of their small size and short life cycles, are thought to be less affected by direct trawling mortality compared with the larger macrofauna. However, nematodes may still be indirectly affected by the physical disturbance of trawling through changing sediment characteristics and food web structure. We determined whether nematode communities on two muddy fishing grounds located in the North Sea and Irish Sea were affected by chronic otter-trawl disturbance and quantified these effects. Nematode abundance, production, and genus richness declined in response to trawling within both areas. Nematode biomass did not respond to trawling intensity. Genus composition was affected by trawling only in the North Sea. The responses in abundance of individual nematode genera to increasing trawling intensity were negative as well as positive. These results indicate that despite their size and fast life cycle, nematodes are affected by intensive trawling on muddy fishing grounds. The loss in secondary production from nematodes can have far-reaching consequences for the integrity of the benthic food web. As bottom trawl fisheries are expanding into ever deeper muddy habitats, the results presented here are an important step towards understanding the global ecosystem effects of bottom trawling.

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