Ecosystem Effects of Fishing: Impacts, Metrics, and

4,18
MB Management Strategies

187
stron

4894
ID International Council for the Explorations of the Sea

2005
rok

CONTENTS

CHAPTER 1

1 REFERENCE POINTS, INCLUDING ECOSYSTEM CONSIDERATIONS1

1.1 Statement of the Issue1

1.2 Specific Reference Points Considerations.2

1.2.1 What ICES already advises2

1.2.2 Additional reference points for species, from an ecosystem perspective.3

1.2.2.1 Genetic reference points for exploited stocks3

1.2.2.2 Reference points for non-target species.4

1.2.2.3 Reference points for ecologically dependent species.5

1.2.2.4 Reference points for species affected by scavengers feeding on discards and offal6

1.2.2.5 Summary of reference points at the species level6

1.2.3 Biological reference points from an ecosystem perspective6

1.3 Models that may give insight.7

1.3.1 Extensions of MSVPA/MSFOR8

1.3.2 Mass-balance models.10

1.3.3 Trophic cascade models.10

1.4 Concluding Remarks11

1.4.1 References11

2 ECOSYSTEM MANAGEMENT OBJECTIVES20

2.1 Introduction20

2.2 Population and Species Reference Points/Objectives.21

2.2.1 Populations of target and non-target species21

2.2.2 Spatial properties22

2.2.3 Dependent species22

2.2.4 Scavenger-caused effects.22

2.3 Habitat Features.22

2.4 Genetic Properties of Populations.23

2.5 Emergent Properties of Ecosystems24

2.5.1 Emergent properties: What are they?.24

2.5.1.1 Does fishing put emergent properties at risk?24

2.6 Objectives and Reference Points for Management.25

2.6.1 Populations and species.25

2.6.1.1 Direct mortality25

2.6.1.2 Range 25

2.6.1.3 Ecologically dependent species.26

2.6.1.4 Scavengers27

2.6.2 Habitats 27

2.6.2.1 Criteria for selection27

2.6.2.2 Possible objectives and reference points27

2.6.3 Genetic properties.28

2.6.4 Emergent properties28

2.7 Conclusions and Way Forward.29

2.8 References30

3 COMMUNITY-SCALE ECOQOS.32

3.1 An Introduction to Ecological Quality Objectives32

3.1.1 History of EcoQOs.32

3.1.2 Terminological issues34

3.1.3 Conceptual issues36

3.1.3.1 Interaction between EcoQ and EcoQO36

3.1.3.2 Role of science.37

3.1.3.3 Approaches to setting EcoQOs37

3.1.3.3.1 Approaches used by other Working Groups or experts37

3.1.3.3.2 Major influences on WGECO’s approach38

3.1.4 Issues regarding implementation.39

3.1.4.1 Lessons learned from past experience.39

3.1.4.2 Applications of lessons from history to the Advisory and Management System needed to

implement EcoQ-based management40 ICES Cooperative Research Report, No. 272 1

3.1.4.3 Practical considerations regarding making EcoQs work together for integrated

management41

3.2 Ecosystem Properties and EcoQ Metrics42

3.2.1 Background.42

3.2.2 Biological diversity.43

3.2.3 Ecological functionality43

3.2.4 Spatial integrity.43

3.2.5 Metrics 43

3.3 Evaluation44

3.3.1 The evaluation method44

3.3.2 Criteria for good Ecological Quality metrics.44

3.3.3 Properties and metrics considered for fish and benthic communities45

3.3.3.1 Biodiversity of species.45

3.3.3.1.1 Biomass45

3.3.3.1.2 Size structure45

3.3.3.1.3 Species identities46

3.3.3.1.4 Species diversity.46

3.3.3.1.5 Life history composition.47

3.3.3.2 Ecological functionality.48

3.3.3.2.1 Resilience48

3.3.3.2.2 Productivity.48

3.3.3.2.3 Trophic structure.49

3.3.3.2.4 Throughput.50

3.3.3.2.5 Body well-being50

3.3.3.3 Spatial integrity51

3.3.4 Results of the evaluation51

3.3.5 Metrics not considered further.51

3.3.6 Gaps 52

3.3.6.1 Metrics of biological diversity.52

3.3.6.2 Metrics of ecological functionality52

3.3.6.3 Metrics of spatial integrity.54

3.4 Framework considerations.57

References.57

4 SEABIRDS AND MARINE MAMMALS IN AN ECOQO-FRAMEWORK.61

4.1 The Approaches taken by WGSE and WGMMPH.61

4.2 Evaluation of the Preliminary Results of WGSE and WGMMPH62

5 ECOQOS FOR FISH AND BENTHIC COMMUNITIES AND THREATENED AND DECLINING

SPECIES.64

5.1 Introduction64

5.2 EcoQOs for North Sea Fish Communities64

5.2.1 Introduction64

5.2.2 Summary of Preparatory Work (information from Piet 2001).65

5.2.2.1 Biomass 65

5.2.2.2 Size-structure65

5.2.2.3 Species diversity66

5.2.2.4 Species composition based on traits66

5.2.2.5 Trophic structure66

5.2.3 Summary.67

5.3 EcoQOs for North Sea Benthic Communities.67

5.3.1 Introduction67

5.3.2 Summary of preparatory work (de Boer et al. 2001) with comments67

5.3.3 Summary.69

5.4 EcoQOs for North Sea Threatened and Declining Species.69

5.4.1 Introduction69

5.4.2 Summary of preparatory work (Gubbay 2001)69

5.4.3 Summary.70

5.5 Application of the WGECO Framework.70

5.5.1 Fish communities70

5.5.2 Benthic communities71

5.5.2.1 Introduction71 2 ICES Cooperative Research Report, No. 272

Section Page

5.5.2.2 Metrics of EcoQ.71

5.5.2.3 Metrics that might be developed further71

5.5.2.4 Adding spatial dimensions.72

5.5.2.5 Conclusion73

5.5.3 Threatened and declining species73

5.5.4 Concluding thoughts and the way forward74

References.74

6 RAPID SCREENING OF METRIC FOR USE AS ECOQS.77

6.1 Introduction77

6.1.1 Concluding remarks78

CHAPTER 2

7 THE NEED FOR LINKING ECOLOGICAL THEORY TO EVALUATING ECOSYSTEM EFFECTS

OF FISHING.80

7.1 Linking the Theoretical Frameworks for Studying Fishing Effects and Ecosystem Structure,

Function, and Dynamics.80

7.2 How to Focus on Theoretical Frameworks with Greatest Promise.80

8 THEORY AND THE PERFORMANCE OF DATA-BASED COMMUNITY METRICS FOR

EVALUATING ECOSYSTEM EFFECTS OF FISHING82

8.1 Integrating Information on North Sea Assemblages from Different Surveys.82

8.1.1 Research vessel surveys.82

8.1.2 Other sampling methods83

8.1.3 Problems with combining gear catches83

8.1.4 References84

8.2 Theory of Community Metrics – Multivariate Indices and Analyses of Communities.85

8.2.1 North Sea region.85

8.2.1.1 Review of current information.85

8.2.1.1.1 Monitoring of changes in small-scale fish assemblages in the North Sea (S. Ehrich and C.