Anne Sell - Academia.edu (original) (raw)

Papers by Anne Sell

ABSTRACT Technische Universität Dresden

Proceedings of the Royal Society B: Biological Sciences, 2000

This is the ¢rst study, to my knowledge, quantifying the respiratory pigment haemoglobin discover... more This is the ¢rst study, to my knowledge, quantifying the respiratory pigment haemoglobin discovered in a deep-sea copepod. Haemoglobin in copepods has previously been documented in only one other species from the deep water of an Italian lake. Specimens of the siphonostomatoid Scotoecetes introrsus Humes were collected during submersible dives at 2500 m depth near a hydrothermal vent at the East Paci¢c Rise (98 N). The haemoglobin content in the copepods' haemolymph was 4.3 § 0.6 m g per individual female (nˆ6) and 1.8 § 0.1 m g per individual male (nˆ6). Weight-speci¢c concentrations of haemoglobin were identical for females and males (0.25 § 0.04 and 0.26 § 0.02 m g per microgram dry weight, respectively). These haemoglobin concentrations are higher than those found in other small crustaceans. Activity of the electron transport system indicated that the respiration rates in S. introrsus (13.7 § 7.7 m l O 2 per milligram dry weight per hour) were similar to those in the shallow-water copepod Acartia tonsa (9.1 § 1.3 m l O 2 per milligram dry weight per hour). It was concluded that the possession of highly concentrated haemoglobin allows S. introrsus to colonize a geologically young, thermally active site such as the vicinity of a hydrothermal vent, despite the prevailing oxygen depletion.

Oecologia, 2000

The presence of plankton predators may induce altered morphology in their potential prey. To date... more The presence of plankton predators may induce altered morphology in their potential prey. To date, the mechanism of induction and adaptive value of such defensive responses have been examined in the laboratory. This study investigated the morphological defense structures induced by the invertebrate predator Chaoborus in two coexisting Daphnia species, D. pulex and D. rosea, in the field. In Piscivore

Marine Policy, 2009

Large intensity and diversity of human activities result in an increase in complexity in the util... more Large intensity and diversity of human activities result in an increase in complexity in the utilization of space. This paper describes the fisheries and a method to map fishing efforts and catches of different fleets by combining vessel monitoring system (VMS) data and logbook data. The method makes it possible to explore the spatial and temporal variability of fishing and the potential impacts of proposed management measures on the fisheries. The method is proposed to be used in the development of management plans for marine protected areas such as Natura 2000 sites, designated to protect vulnerable habitats and species.

Limnology and Oceanography, 2001

Predation is thought to be an important source of mortality in the early life stages of fish and ... more Predation is thought to be an important source of mortality in the early life stages of fish and copepods on Georges Bank. Omnivorous copepods may be predators on copepod eggs and nauplii, but data on feeding rates or selectivity are scarce. As part of the GLOBEC Georges Bank program, we generated functional response curves for the omnivorous copepods Metridia lucens, Centropages typicus, and Temora longicornis feeding on the eggs and nauplii of Calanus finmarchicus or Pseudocalanus spp. in shipboard predation trials. Neither C. typicus nor M. lucens reached saturation feeding on Calanus eggs until prey concentration was Ͼ400 L Ϫ1 . Individual M. lucens and C. typicus ingested up to 34 Ϯ 9 (mean Ϯ SD, n ϭ 3) and 24 Ϯ 14 eggs d Ϫ1 , respectively (6ЊC). T. longicornis was more abundant in late spring, when they ingested Calanus eggs at rates similar to those of C. typicus. At ambient prey concentrations, ingestion rates of Calanus nauplii were higher than rates of Calanus eggs for the predator M. lucens but were similar for C. typicus. Advanced naupliar stages were less susceptible to predation than young stages. Pseudocalanus nauplii moved faster and were ingested at lower rates than similarly sized Calanus nauplii. Predation rates increased with increasing temperature for the warm-water species C. typicus but decreased for the cold-water species M. lucens. These results may contribute to models predicting the development of copepod populations and their availability to larval fish.

Journal of Sea Research, 2013

The interdependence between groundfish assemblages and habitat properties was investigated on the... more The interdependence between groundfish assemblages and habitat properties was investigated on the Dogger Bank in the North Sea. Abiotic habitat parameters considered included topography, hydrographic conditions, sediment composition, and the biotic habitat variable the prevailing benthic invertebrates. Distinct epi-and infauna communities occurred at different locations on the Dogger Bank. Fish assemblages were clearly linked to both the biotic and abiotic habitat characteristics.

Journal of Plankton Research, 1992

ABSTRACT Phytoplankton from Plubetasee were investigated with regard to photosynthetic activity a... more ABSTRACT Phytoplankton from Plubetasee were investigated with regard to photosynthetic activity and the simultaneously occurring release of extracellular organic compounds (EOC). rhe chemical properties, as well as the quantity of EOC, differ considerably depending on the community's seasonally varying composition and on individual physiological status. EOC constituted up to 99.9% (minimum 30.5%, mean 65.9%) of the phytoplankton's primary production. EOC quality seemed to be decisive for uptake as a carbon source utilized first by aquatic bacteria. In early summer, EOC were rapidly incorporated by microorganisms and represented an important contribution to their biomass production. In contrast, the exudates released during late summer (August and September) predominantly consisted of components slowly incorporated by bacteria. These exudates were compounds of presumably high molecular weight.

Helgoland Marine Research, 2013

Your article is protected by copyright and all rights are held exclusively by Springer-Verlag and... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag and AWI. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to selfarchive your work, please use the accepted author's version for posting to your own website or your institution's repository. You may further deposit the accepted author's version on a funder's repository at a funder's request, provided it is not made publicly available until 12 months after publication.

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 1998

Low oxygen concentrations ( B3 mg O 2 l − 1 ) in the surrounding water body usually cause a marke... more Low oxygen concentrations ( B3 mg O 2 l − 1 ) in the surrounding water body usually cause a marked decline of respiration and filtering rates in Daphnia (Crustacea, Cladocera). Typically during summer, when low-oxygen conditions develop in the metalimnion, the abundance of Daphnia in thermally stratified eutrophic lakes is restricted to the high-oxygen environment of the epilimnion. At the same time, food resources are depleted in the epilimnion and accumulate in the metalimnion due to sedimentation of phytoplankton and detritus. This study investigated the spatial distribution and possible physiological adaptation of Daphnia spp. in a eutrophic lake at Gräfenhain (Germany). The described conditions resulted in an almost complete vertical separation of the two coexisting Daphnia species (D. pulex and D. rosea). D. pulex amounted to B10% of all daphnids in the epilimnion and to \96% in the low-oxygen layer around the metalimnion. This pattern was consistent, independent of time of day. Both Daphnia spp. were able to produce haemoglobin (Hb). D. pulex intensely enhanced the Hb concentration during individual growth up to 125 mg Hb g − 1 dry weight, which is 5-fold the concentration found in the neonates. In contrast, D. rosea did not enhance Hb concentration during ontogenesis. Birth rates in the metalimnetic D. pulex were high in comparison to those of the epilimnetic D. rosea. The ability to produce Hb appears to allow D. pulex to colonize low-oxygen layers and to exploit food resources therein.

A research cruise on Dogger Bank in the central North Sea was conducted to investigate the influe... more A research cruise on Dogger Bank in the central North Sea was conducted to investigate the influence of habitat properties on the diversity of bottom fish assemblages. In April/May 2006, 35 stations across the bank were sampled for a combined analysis of the bank's topography, hydrography, epibenthic communities and fish assemblages. The composition of epifauna as well as the assemblages

Marine Ecology Progress Series, 2002

ABSTRACT: We examined and quantified the contributions of copepods and appendicularians to the ve... more ABSTRACT: We examined and quantified the contributions of copepods and appendicularians to the vertical flux of carbon during autumn and spring in Gullmar Fjord (west coast of Sweden). Faecal pellet-production rate was determined for major copepod ...

Http Dx Doi Org 10 1080 17451000500396435, Feb 18, 2007

Offshore Wind Energy, 2006

ABSTRACT The installation of wind parks could, through local alteration of habitat structures, po... more ABSTRACT The installation of wind parks could, through local alteration of habitat structures, potentially affect fish populations present in the area. To provide the most rigid analysis of this effect, the specific sites for planned wind parks should ideally be investigated through a multi-annual base line study before and another multi-annual study after installation of the turbines. However, this would be very cost-intensive, and we are not aware of any wind park where the entire fish community has been investigated to such an extend. With the following summary of ongoing independent longterm fisheries research within the two German Exclusive Economic Zones (EEZs) and the 12 nm territorial zones (German waters), we intend to provide the information currently available for predictions of the possible impact of new facilities. Our interpretation of observations from these fisheries surveys is based on a number of fundamental characteristics of the fish and their habitats in the German waters of the North and Baltic Seas: A fish species will occur in a certain maritime area either if prerequisites exist which allow the species to stay in this particular suitable habitat for an extended time period, or if the species passes through the area while migrating to another area (e.g. feeding or spawning migrations). Alternatively, adverse circumstances may displace a fish species to a region it does not otherwise inhabit. The typical fish fauna found associated with a habitat belongs to the first category. Good examples of the second category are anadromous fish species that migrate from rivers into the sea for feeding and return to the rivers for spawning. The third category includes Irrgaste, species that enter a more or less hostile area as a result of bad weather conditions and an inflow of water masses from other areas. To what habitat characteristics do fish respond? The availability of food and hydrographical parameters like water temperature and salinity are important for the survival and reproduction of most fish species. Other important habitat properties include water depth, chemical properties such as sufficiently high oxygen concentrations in the sea water (especially in the Baltic Sea, where in late summer the deep waters are often oxygendepleted) and, particularly for the near-bottom fish fauna, the type of sediment of the sea ground. The German North Sea is an area in which habitat characteristics can change not only seasonally but also over a period of days. To be successful, fish species must adapt to this variable habitat. Heavy rain expands the fresh water plume from the rivers into the German Bight, decreases the salinity of the near-shore water masses and shifts the river plume fronts further into the sea. The seasonal differences in bottom water temperature of the German North Sea (variation up to 15C) are the highest in the entire North Sea. Cold winters with ice cover in the river mouths and in the Wadden Sea cause bottom water temperatures in the inner German Bight to drop to less than 5C, which kills most stationary benthic animals down to a water depth of 35 m and leads the fish to migrate to deeper zones. On the other hand, in most parts of the EEZ the water column is, due to strong tidal currents, well-mixed even during hot summers, with bottom temperatures reaching up to nearly 20C. In the mostly shallow waters, the turbulence of the waves during heavy gales reaches the bottom and whirls up the sediment. The high turbidity affects not only the benthic infauna and epifauna, but also the vertical distribution of fishes (Ehrich and Stransky 1999) and their dominating reproductive strategy, with pelagic eggs that cannot be buried by sediment. Unlike the North Sea, the Baltic Sea lacks strong tidal currents, and its waters are also much less saline. Due to its strong fresh water inflow, predominantly in the Northeast, low evaporation rates, and its limited connection to North Sea waters, surface salinity values decrease from West to East. The German Baltic Sea areas belong to the transition zone between the North Sea and the Baltic Proper. Surface salinities range from > 17 psu in the Kiel Bight to < 8 psu in the Pomeranian Bight. In the bottom layers higher salinity values can be obtained as a consequence of highly variable intrusion of North Sea waters through the Danish straits. Consequently, the fish fauna of the Baltic is a mixture of relatively euryhaline marine and fresh water species, with a decreasing number of species towards the east (Hempel and Nellen 1974). Particularly in summer the gas exchange between waters in the bottom layers and surface waters is very restricted by a strong pycnocline. Thus, oxygen depletion in the bottom layers is a common feature of the deeper Baltic Sea areas in late summer. Long-term investigations of the fish fauna in both, the German North Sea and Baltic Sea areas have been conducted by the German Federal Research Centre for Fisheries…

A research cruise on Dogger Bank in the central North Sea was conducted to investigate the influe... more A research cruise on Dogger Bank in the central North Sea was conducted to investigate the influence of habitat properties on the diversity of bottom fish assemblages. In April/May 2006, 35 stations across the bank were sampled for a combined analysis of the bank's topography, hydrography, epibenthic communities and fish assemblages. The composition of epifauna as well as the assemblages of small demersal fish were obtained from a 2 m fine-mesh beam trawl, the assemblage of the larger groundfish through a standardized GOV bottom trawl as used during the International Bottom Trawl Survey. Using multivariate statistics, the assemblages of fish species are considered in relation to differences in the physical and biological structure of the local habitats. In addition, focal points in the utilization of specific habitats by individual species are characterized. Introductions

Marine Ecology Progress Series, 2002

ABSTRACT: We examined and quantified the contributions of copepods and appendicularians to the ve... more ABSTRACT: We examined and quantified the contributions of copepods and appendicularians to the vertical flux of carbon during autumn and spring in Gullmar Fjord (west coast of Sweden). Faecal pellet-production rate was determined for major copepod ...

Marine Biology Research, 2005

... Figure 1. Vertical profiles of temperature (8C) and salinity (PSU) at the station taken at 6 ... more ... Figure 1. Vertical profiles of temperature (8C) and salinity (PSU) at the station taken at 6 h intervals. Grazing impact of Oikopleura dioica and copepods on plankton 367 Page 4. C m(3 and dominated by Pseudo-nitzschia sp (26 mg C m(3). Bacteria were also important prey (19 ...

Journal of Applied Ichthyology, 2010

During a fisheries research cruise on the Dogger Bank in the central North Sea, we studied the ro... more During a fisheries research cruise on the Dogger Bank in the central North Sea, we studied the role of diet for the condition of grey gurnard (Eutrigla gurnardus). Seventeen stations across the Dogger Bank were sampled with the GOV otter trawl in April⁄May 2006. Each fish sampled was categorised according to three feeding types: a predator specialised on fish, on invertebrates or having a mixed diet, depending on the percentage of fish and⁄or invertebrates in the stomach. These predator-prey categories were compared by means of three condition indices: FultonÕs condition factor, a hepatosomatic index (HSI) and a gonadosomatic index (GSI). FultonÕs condition factor provided evidence that a specialisation on fish prey increases the condition of grey gurnards in terms of the length-specific individual weight. In contrast, the HSI scored highest for predators feeding on a mixed diet. The GSI showed a tendency to be highest with a diet dominated by invertebrate prey, but differences between the three predatorprey categories were not significant. Based on the topography of the Dogger Bank, stations were allocated in shallow and deep regions. At shallow stations, the brown shrimp Crangon allmani and sandeels, combining basically the taxa Ammodytidae, Ammodytes juv. and Ammodytes marinus, were typically observed in stomach contents of gurnards whereas the amphipod Hyperia galba was predominantly found in gurnards sampled in deep regions.

Global Change Biology, 2016

The Paris Conference of Parties (COP21) agreement renewed momentum for action against climate cha... more The Paris Conference of Parties (COP21) agreement renewed momentum for action against climate change, creating the space for solutions for conservation of the ocean addressing two of its largest threats: climate change and ocean acidification (CCOA). Recent arguments that ocean policies disregard a mature conservation research field, and that protected areas cannot address climate change may be over-simplistic at this time when dynamic solutions for the management of changing oceans are needed. We propose a novel approach, based on spatial meta-analysis of climate impact models, to improve the positioning of marine protected areas to limit CCOA impacts. We do this by estimating the vulnerability of ocean ecosystems to CCOA in a spatially-explicit manner, and then co-mapping human activities such as the placement of renewable energy developments and the distribution of marine protected areas. We test this approach in the NE Atlantic considering also how CCOA impacts the base of the food web which supports protected species, an aspect often neglected in conservation studies. We found that, in this case, current regional conservation plans protect areas with low ecosystem-level vulnerability to CCOA, but disregard how species may re-distribute to new, suitable and productive habitats. Under current plans, these areas remain open to commercial extraction and other uses. Here, and worldwide, ocean conservation strategies under CCOA must recognize the long-term importance of these habitat refuges, and studies such as this one are needed to identify them. Protecting these areas creates adaptive, climate-ready and ecosystem-level policy options for conservation, suitable for changing oceans. This article is protected by copyright. All rights reserved.

Estuarine, Coastal and Shelf Science, 2016

ABSTRACT Technische Universität Dresden

Proceedings of the Royal Society B: Biological Sciences, 2000

This is the ¢rst study, to my knowledge, quantifying the respiratory pigment haemoglobin discover... more This is the ¢rst study, to my knowledge, quantifying the respiratory pigment haemoglobin discovered in a deep-sea copepod. Haemoglobin in copepods has previously been documented in only one other species from the deep water of an Italian lake. Specimens of the siphonostomatoid Scotoecetes introrsus Humes were collected during submersible dives at 2500 m depth near a hydrothermal vent at the East Paci¢c Rise (98 N). The haemoglobin content in the copepods' haemolymph was 4.3 § 0.6 m g per individual female (nˆ6) and 1.8 § 0.1 m g per individual male (nˆ6). Weight-speci¢c concentrations of haemoglobin were identical for females and males (0.25 § 0.04 and 0.26 § 0.02 m g per microgram dry weight, respectively). These haemoglobin concentrations are higher than those found in other small crustaceans. Activity of the electron transport system indicated that the respiration rates in S. introrsus (13.7 § 7.7 m l O 2 per milligram dry weight per hour) were similar to those in the shallow-water copepod Acartia tonsa (9.1 § 1.3 m l O 2 per milligram dry weight per hour). It was concluded that the possession of highly concentrated haemoglobin allows S. introrsus to colonize a geologically young, thermally active site such as the vicinity of a hydrothermal vent, despite the prevailing oxygen depletion.

Oecologia, 2000

The presence of plankton predators may induce altered morphology in their potential prey. To date... more The presence of plankton predators may induce altered morphology in their potential prey. To date, the mechanism of induction and adaptive value of such defensive responses have been examined in the laboratory. This study investigated the morphological defense structures induced by the invertebrate predator Chaoborus in two coexisting Daphnia species, D. pulex and D. rosea, in the field. In Piscivore

Marine Policy, 2009

Large intensity and diversity of human activities result in an increase in complexity in the util... more Large intensity and diversity of human activities result in an increase in complexity in the utilization of space. This paper describes the fisheries and a method to map fishing efforts and catches of different fleets by combining vessel monitoring system (VMS) data and logbook data. The method makes it possible to explore the spatial and temporal variability of fishing and the potential impacts of proposed management measures on the fisheries. The method is proposed to be used in the development of management plans for marine protected areas such as Natura 2000 sites, designated to protect vulnerable habitats and species.

Limnology and Oceanography, 2001

Predation is thought to be an important source of mortality in the early life stages of fish and ... more Predation is thought to be an important source of mortality in the early life stages of fish and copepods on Georges Bank. Omnivorous copepods may be predators on copepod eggs and nauplii, but data on feeding rates or selectivity are scarce. As part of the GLOBEC Georges Bank program, we generated functional response curves for the omnivorous copepods Metridia lucens, Centropages typicus, and Temora longicornis feeding on the eggs and nauplii of Calanus finmarchicus or Pseudocalanus spp. in shipboard predation trials. Neither C. typicus nor M. lucens reached saturation feeding on Calanus eggs until prey concentration was Ͼ400 L Ϫ1 . Individual M. lucens and C. typicus ingested up to 34 Ϯ 9 (mean Ϯ SD, n ϭ 3) and 24 Ϯ 14 eggs d Ϫ1 , respectively (6ЊC). T. longicornis was more abundant in late spring, when they ingested Calanus eggs at rates similar to those of C. typicus. At ambient prey concentrations, ingestion rates of Calanus nauplii were higher than rates of Calanus eggs for the predator M. lucens but were similar for C. typicus. Advanced naupliar stages were less susceptible to predation than young stages. Pseudocalanus nauplii moved faster and were ingested at lower rates than similarly sized Calanus nauplii. Predation rates increased with increasing temperature for the warm-water species C. typicus but decreased for the cold-water species M. lucens. These results may contribute to models predicting the development of copepod populations and their availability to larval fish.

Journal of Sea Research, 2013

The interdependence between groundfish assemblages and habitat properties was investigated on the... more The interdependence between groundfish assemblages and habitat properties was investigated on the Dogger Bank in the North Sea. Abiotic habitat parameters considered included topography, hydrographic conditions, sediment composition, and the biotic habitat variable the prevailing benthic invertebrates. Distinct epi-and infauna communities occurred at different locations on the Dogger Bank. Fish assemblages were clearly linked to both the biotic and abiotic habitat characteristics.

Journal of Plankton Research, 1992

ABSTRACT Phytoplankton from Plubetasee were investigated with regard to photosynthetic activity a... more ABSTRACT Phytoplankton from Plubetasee were investigated with regard to photosynthetic activity and the simultaneously occurring release of extracellular organic compounds (EOC). rhe chemical properties, as well as the quantity of EOC, differ considerably depending on the community's seasonally varying composition and on individual physiological status. EOC constituted up to 99.9% (minimum 30.5%, mean 65.9%) of the phytoplankton's primary production. EOC quality seemed to be decisive for uptake as a carbon source utilized first by aquatic bacteria. In early summer, EOC were rapidly incorporated by microorganisms and represented an important contribution to their biomass production. In contrast, the exudates released during late summer (August and September) predominantly consisted of components slowly incorporated by bacteria. These exudates were compounds of presumably high molecular weight.

Helgoland Marine Research, 2013

Your article is protected by copyright and all rights are held exclusively by Springer-Verlag and... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag and AWI. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to selfarchive your work, please use the accepted author's version for posting to your own website or your institution's repository. You may further deposit the accepted author's version on a funder's repository at a funder's request, provided it is not made publicly available until 12 months after publication.

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 1998

Low oxygen concentrations ( B3 mg O 2 l − 1 ) in the surrounding water body usually cause a marke... more Low oxygen concentrations ( B3 mg O 2 l − 1 ) in the surrounding water body usually cause a marked decline of respiration and filtering rates in Daphnia (Crustacea, Cladocera). Typically during summer, when low-oxygen conditions develop in the metalimnion, the abundance of Daphnia in thermally stratified eutrophic lakes is restricted to the high-oxygen environment of the epilimnion. At the same time, food resources are depleted in the epilimnion and accumulate in the metalimnion due to sedimentation of phytoplankton and detritus. This study investigated the spatial distribution and possible physiological adaptation of Daphnia spp. in a eutrophic lake at Gräfenhain (Germany). The described conditions resulted in an almost complete vertical separation of the two coexisting Daphnia species (D. pulex and D. rosea). D. pulex amounted to B10% of all daphnids in the epilimnion and to \96% in the low-oxygen layer around the metalimnion. This pattern was consistent, independent of time of day. Both Daphnia spp. were able to produce haemoglobin (Hb). D. pulex intensely enhanced the Hb concentration during individual growth up to 125 mg Hb g − 1 dry weight, which is 5-fold the concentration found in the neonates. In contrast, D. rosea did not enhance Hb concentration during ontogenesis. Birth rates in the metalimnetic D. pulex were high in comparison to those of the epilimnetic D. rosea. The ability to produce Hb appears to allow D. pulex to colonize low-oxygen layers and to exploit food resources therein.

A research cruise on Dogger Bank in the central North Sea was conducted to investigate the influe... more A research cruise on Dogger Bank in the central North Sea was conducted to investigate the influence of habitat properties on the diversity of bottom fish assemblages. In April/May 2006, 35 stations across the bank were sampled for a combined analysis of the bank's topography, hydrography, epibenthic communities and fish assemblages. The composition of epifauna as well as the assemblages

Marine Ecology Progress Series, 2002

ABSTRACT: We examined and quantified the contributions of copepods and appendicularians to the ve... more ABSTRACT: We examined and quantified the contributions of copepods and appendicularians to the vertical flux of carbon during autumn and spring in Gullmar Fjord (west coast of Sweden). Faecal pellet-production rate was determined for major copepod ...

Http Dx Doi Org 10 1080 17451000500396435, Feb 18, 2007

Offshore Wind Energy, 2006

ABSTRACT The installation of wind parks could, through local alteration of habitat structures, po... more ABSTRACT The installation of wind parks could, through local alteration of habitat structures, potentially affect fish populations present in the area. To provide the most rigid analysis of this effect, the specific sites for planned wind parks should ideally be investigated through a multi-annual base line study before and another multi-annual study after installation of the turbines. However, this would be very cost-intensive, and we are not aware of any wind park where the entire fish community has been investigated to such an extend. With the following summary of ongoing independent longterm fisheries research within the two German Exclusive Economic Zones (EEZs) and the 12 nm territorial zones (German waters), we intend to provide the information currently available for predictions of the possible impact of new facilities. Our interpretation of observations from these fisheries surveys is based on a number of fundamental characteristics of the fish and their habitats in the German waters of the North and Baltic Seas: A fish species will occur in a certain maritime area either if prerequisites exist which allow the species to stay in this particular suitable habitat for an extended time period, or if the species passes through the area while migrating to another area (e.g. feeding or spawning migrations). Alternatively, adverse circumstances may displace a fish species to a region it does not otherwise inhabit. The typical fish fauna found associated with a habitat belongs to the first category. Good examples of the second category are anadromous fish species that migrate from rivers into the sea for feeding and return to the rivers for spawning. The third category includes Irrgaste, species that enter a more or less hostile area as a result of bad weather conditions and an inflow of water masses from other areas. To what habitat characteristics do fish respond? The availability of food and hydrographical parameters like water temperature and salinity are important for the survival and reproduction of most fish species. Other important habitat properties include water depth, chemical properties such as sufficiently high oxygen concentrations in the sea water (especially in the Baltic Sea, where in late summer the deep waters are often oxygendepleted) and, particularly for the near-bottom fish fauna, the type of sediment of the sea ground. The German North Sea is an area in which habitat characteristics can change not only seasonally but also over a period of days. To be successful, fish species must adapt to this variable habitat. Heavy rain expands the fresh water plume from the rivers into the German Bight, decreases the salinity of the near-shore water masses and shifts the river plume fronts further into the sea. The seasonal differences in bottom water temperature of the German North Sea (variation up to 15C) are the highest in the entire North Sea. Cold winters with ice cover in the river mouths and in the Wadden Sea cause bottom water temperatures in the inner German Bight to drop to less than 5C, which kills most stationary benthic animals down to a water depth of 35 m and leads the fish to migrate to deeper zones. On the other hand, in most parts of the EEZ the water column is, due to strong tidal currents, well-mixed even during hot summers, with bottom temperatures reaching up to nearly 20C. In the mostly shallow waters, the turbulence of the waves during heavy gales reaches the bottom and whirls up the sediment. The high turbidity affects not only the benthic infauna and epifauna, but also the vertical distribution of fishes (Ehrich and Stransky 1999) and their dominating reproductive strategy, with pelagic eggs that cannot be buried by sediment. Unlike the North Sea, the Baltic Sea lacks strong tidal currents, and its waters are also much less saline. Due to its strong fresh water inflow, predominantly in the Northeast, low evaporation rates, and its limited connection to North Sea waters, surface salinity values decrease from West to East. The German Baltic Sea areas belong to the transition zone between the North Sea and the Baltic Proper. Surface salinities range from > 17 psu in the Kiel Bight to < 8 psu in the Pomeranian Bight. In the bottom layers higher salinity values can be obtained as a consequence of highly variable intrusion of North Sea waters through the Danish straits. Consequently, the fish fauna of the Baltic is a mixture of relatively euryhaline marine and fresh water species, with a decreasing number of species towards the east (Hempel and Nellen 1974). Particularly in summer the gas exchange between waters in the bottom layers and surface waters is very restricted by a strong pycnocline. Thus, oxygen depletion in the bottom layers is a common feature of the deeper Baltic Sea areas in late summer. Long-term investigations of the fish fauna in both, the German North Sea and Baltic Sea areas have been conducted by the German Federal Research Centre for Fisheries…

A research cruise on Dogger Bank in the central North Sea was conducted to investigate the influe... more A research cruise on Dogger Bank in the central North Sea was conducted to investigate the influence of habitat properties on the diversity of bottom fish assemblages. In April/May 2006, 35 stations across the bank were sampled for a combined analysis of the bank's topography, hydrography, epibenthic communities and fish assemblages. The composition of epifauna as well as the assemblages of small demersal fish were obtained from a 2 m fine-mesh beam trawl, the assemblage of the larger groundfish through a standardized GOV bottom trawl as used during the International Bottom Trawl Survey. Using multivariate statistics, the assemblages of fish species are considered in relation to differences in the physical and biological structure of the local habitats. In addition, focal points in the utilization of specific habitats by individual species are characterized. Introductions

Marine Ecology Progress Series, 2002

ABSTRACT: We examined and quantified the contributions of copepods and appendicularians to the ve... more ABSTRACT: We examined and quantified the contributions of copepods and appendicularians to the vertical flux of carbon during autumn and spring in Gullmar Fjord (west coast of Sweden). Faecal pellet-production rate was determined for major copepod ...

Marine Biology Research, 2005

... Figure 1. Vertical profiles of temperature (8C) and salinity (PSU) at the station taken at 6 ... more ... Figure 1. Vertical profiles of temperature (8C) and salinity (PSU) at the station taken at 6 h intervals. Grazing impact of Oikopleura dioica and copepods on plankton 367 Page 4. C m(3 and dominated by Pseudo-nitzschia sp (26 mg C m(3). Bacteria were also important prey (19 ...

Journal of Applied Ichthyology, 2010

During a fisheries research cruise on the Dogger Bank in the central North Sea, we studied the ro... more During a fisheries research cruise on the Dogger Bank in the central North Sea, we studied the role of diet for the condition of grey gurnard (Eutrigla gurnardus). Seventeen stations across the Dogger Bank were sampled with the GOV otter trawl in April⁄May 2006. Each fish sampled was categorised according to three feeding types: a predator specialised on fish, on invertebrates or having a mixed diet, depending on the percentage of fish and⁄or invertebrates in the stomach. These predator-prey categories were compared by means of three condition indices: FultonÕs condition factor, a hepatosomatic index (HSI) and a gonadosomatic index (GSI). FultonÕs condition factor provided evidence that a specialisation on fish prey increases the condition of grey gurnards in terms of the length-specific individual weight. In contrast, the HSI scored highest for predators feeding on a mixed diet. The GSI showed a tendency to be highest with a diet dominated by invertebrate prey, but differences between the three predatorprey categories were not significant. Based on the topography of the Dogger Bank, stations were allocated in shallow and deep regions. At shallow stations, the brown shrimp Crangon allmani and sandeels, combining basically the taxa Ammodytidae, Ammodytes juv. and Ammodytes marinus, were typically observed in stomach contents of gurnards whereas the amphipod Hyperia galba was predominantly found in gurnards sampled in deep regions.

Global Change Biology, 2016

The Paris Conference of Parties (COP21) agreement renewed momentum for action against climate cha... more The Paris Conference of Parties (COP21) agreement renewed momentum for action against climate change, creating the space for solutions for conservation of the ocean addressing two of its largest threats: climate change and ocean acidification (CCOA). Recent arguments that ocean policies disregard a mature conservation research field, and that protected areas cannot address climate change may be over-simplistic at this time when dynamic solutions for the management of changing oceans are needed. We propose a novel approach, based on spatial meta-analysis of climate impact models, to improve the positioning of marine protected areas to limit CCOA impacts. We do this by estimating the vulnerability of ocean ecosystems to CCOA in a spatially-explicit manner, and then co-mapping human activities such as the placement of renewable energy developments and the distribution of marine protected areas. We test this approach in the NE Atlantic considering also how CCOA impacts the base of the food web which supports protected species, an aspect often neglected in conservation studies. We found that, in this case, current regional conservation plans protect areas with low ecosystem-level vulnerability to CCOA, but disregard how species may re-distribute to new, suitable and productive habitats. Under current plans, these areas remain open to commercial extraction and other uses. Here, and worldwide, ocean conservation strategies under CCOA must recognize the long-term importance of these habitat refuges, and studies such as this one are needed to identify them. Protecting these areas creates adaptive, climate-ready and ecosystem-level policy options for conservation, suitable for changing oceans. This article is protected by copyright. All rights reserved.

Estuarine, Coastal and Shelf Science, 2016