Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Introduction
- 2 Effects of fisheries on ecosystems: just another top predator?
- 3 Physical forcing in the southwest Atlantic: ecosystem control
- 4 The use of biologically meaningful oceanographic indices to separate the effects of climate and fisheries on seabird breeding success
- 5 Linking predator foraging behaviour and diet with variability in continental shelf ecosystems: grey seals of eastern Canada
- 6 Distribution and foraging interactions of seabirds and marine mammals in the North Sea: multispecies foraging assemblages and habitat-specific feeding strategies
- 7 Spatial and temporal variation in the diets of polar bears across the Canadian Arctic: indicators of changes in prey populations and environment
- 8 Biophysical influences on seabird trophic assessments
- 9 Consequences of prey distribution for the foraging behaviour of top predators
- 10 Identifying drivers of change: did fisheries play a role in the spread of North Atlantic fulmars?
- 11 Monitoring predator–prey interactions using multiple predator species: the South Georgia experience
- 12 Impacts of oceanography on the foraging dynamics of seabirds in the North Sea
- 13 Foraging energetics of North Sea birds confronted with fluctuating prey availability
- 14 How many fish should we leave in the sea for seabirds and marine mammals?
- 15 Does the prohibition of industrial fishing for sandeels have any impact on local gadoid populations?
- 16 Use of gannets to monitor prey availability in the northeast Atlantic Ocean: colony size, diet and foraging behaviour
- 17 Population dynamics of Antarctic krill Euphausia superba at South Georgia: sampling with predators provides new insights
- 18 The functional response of generalist predators and its implications for the monitoring of marine ecosystems
- 19 The method of multiple hypotheses and the decline of Steller sea lions in western Alaska
- 20 Modelling the behaviour of individuals and groups of animals foraging in heterogeneous environments
- 21 The Scenario Barents Sea study: a case of minimal realistic modelling to compare management strategies for marine ecosystems
- 22 Setting management goals using information from predators
- 23 Marine reserves and higher predators
- 24 Marine management: can objectives be set for marine top predators?
- Index
- References
17 - Population dynamics of Antarctic krill Euphausia superba at South Georgia: sampling with predators provides new insights
Published online by Cambridge University Press: 31 July 2009
Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Introduction
- 2 Effects of fisheries on ecosystems: just another top predator?
- 3 Physical forcing in the southwest Atlantic: ecosystem control
- 4 The use of biologically meaningful oceanographic indices to separate the effects of climate and fisheries on seabird breeding success
- 5 Linking predator foraging behaviour and diet with variability in continental shelf ecosystems: grey seals of eastern Canada
- 6 Distribution and foraging interactions of seabirds and marine mammals in the North Sea: multispecies foraging assemblages and habitat-specific feeding strategies
- 7 Spatial and temporal variation in the diets of polar bears across the Canadian Arctic: indicators of changes in prey populations and environment
- 8 Biophysical influences on seabird trophic assessments
- 9 Consequences of prey distribution for the foraging behaviour of top predators
- 10 Identifying drivers of change: did fisheries play a role in the spread of North Atlantic fulmars?
- 11 Monitoring predator–prey interactions using multiple predator species: the South Georgia experience
- 12 Impacts of oceanography on the foraging dynamics of seabirds in the North Sea
- 13 Foraging energetics of North Sea birds confronted with fluctuating prey availability
- 14 How many fish should we leave in the sea for seabirds and marine mammals?
- 15 Does the prohibition of industrial fishing for sandeels have any impact on local gadoid populations?
- 16 Use of gannets to monitor prey availability in the northeast Atlantic Ocean: colony size, diet and foraging behaviour
- 17 Population dynamics of Antarctic krill Euphausia superba at South Georgia: sampling with predators provides new insights
- 18 The functional response of generalist predators and its implications for the monitoring of marine ecosystems
- 19 The method of multiple hypotheses and the decline of Steller sea lions in western Alaska
- 20 Modelling the behaviour of individuals and groups of animals foraging in heterogeneous environments
- 21 The Scenario Barents Sea study: a case of minimal realistic modelling to compare management strategies for marine ecosystems
- 22 Setting management goals using information from predators
- 23 Marine reserves and higher predators
- 24 Marine management: can objectives be set for marine top predators?
- Index
- References
Summary
Variability in the Southern Ocean is often characterized by fluctuations in the distribution and abundance of a single dominant zooplankton species, Antarctic krill Euphausia superba. The ability to sample krill in the diet of predators at temporal scales not available using conventional (i.e. ship-based) sampling methods has provided the basis for a re-evaluation of the role of high rates of growth and mortality, as well as recruitment variability, in generating variability in krill abundance at South Georgia. In addition, the use of a consistent index of krill population size composition from the diet of predators at South Georgia over the past decade has provided evidence for a relationship between sea-surface temperature and the level of krill recruitment. Predators that depend on krill not only show distinct behavioural responses to changes in krill abundance but also provide dietary data that help us to understand the mechanisms underlying the population dynamics of krill. Where the diet of predators includes commercial prey species, they can provide information on the key life-history variables of these species that are fundamental to reducing uncertainty in fisheries management models.
VARIABILITY IN THE SOUTHERN OCEAN
Understanding the causes and consequences of natural variability in marine ecosystems is a prerequisite to determining the nature and extent of changes of anthropogenic origin and is a central component of ecosystem-based approaches to fisheries management.
- Type
- Chapter
- Information
- Top Predators in Marine EcosystemsTheir Role in Monitoring and Management, pp. 249 - 261Publisher: Cambridge University PressPrint publication year: 2006
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