The Net Effect? - Whale and Dolphin Conservation Society

Contents
1. Introduction 6
1.1 Bycatch worldwide 6
1.2 Cetacean bycatch in the
north-east Atlantic 7
1.3 Current state of play 8
2. Cetaceans Under Threat 10
2.1 Cetacean species of the
north-east Atlantic 10
2.2 Harbour porpoise Phocoena phocoena 10
2.2.1 Ecology, population and distribution 10
2.2.2 Bycatch of harbour porpoises 11
2.3 Common dolphin Delphinus delphis 13
2.3.1 Ecology, population and distribution 13
2.3.2 Bycatch of common dolphins 14
2.4 Striped dolphin Stenella coeruleoalba 17
2.4.1 Ecology, population and distribution 17
2.4.2 Bycatch of striped dolphins 18
2.5 Atlantic white-sided dolphin
Lagenorhyncus acutus 18
2.5.1 Ecology, population and distribution 18
2.5.2 Bycatch of Atlantic white-sided dolphins 19
2.6 Bottlenose dolphin Tursiops truncatus 20
2.6.1 Ecology, population and distribution 20
2.6.2 Bycatch of bottlenose dolphins 21
2.7 Long-finned pilot whale Globicephala melas 21
2.7.1 Ecology, population and distribution 21
2.7.2 Bycatch of long-finned pilot whales 22
3. Fisheries associated with Bycatch 23
3.1 Overview 23
3.2 Pelagic trawls 24
3.2.1 French pelagic trawl fisheries 26
3.2.2 Dutch pelagic trawl fisheries 27
3.2.3 UK pelagic trawl fisheries 29
3.2.4 Irish pelagic trawl fisheries 30
3.2.5 Danish pelagic trawl fisheries 32
3.2.6 Spanish pelagic trawl fisheries 32
3.3 Bottom-set gillnets 33
3.3.1 Danish bottom-set gillnets 32
3.3.2 UK bottom-set gillnets 34
3.3.3 French, Portuguese and Spanish
bottom-set gillnets 35
3.3.4 Baltic bottom-set gillnets 35
3.4 Driftnets 36
3.4.1 North-east Atlantic and Mediterranean 36
3.4.2 Baltic 37
4. Measures to reduce Bycatch 39
4.1 Why cetaceans get caught 39
4.2 Technical mitigation measures 40
The Net Effect?
A WDCS report for Greenpeace
4.2.1 Exclusion devices 40
4.2.2 Acoustic deterrent devices
(pingers) in set nets 42
4.2.3 Acoustic deterrent devices
(pingers) in pelagic trawls 44
4.2.4 Net modifications 45
4.3 Management mitigation measures 45
4.3.1 Effort reduction 45
4.3.2 Time and area restrictions 46
4.3.3 Alternative gear types 47
4.3.4 Emergency measures 47
4.4 Bycatch management framework 47
5. Bycatch regulation 49
5.1 Regulation of bycatch around the world 49
5.1.1 International treaties, conventions
and agreements 49
5.1.2 National legislation elsewhere 49
5.2 Existing obligations within
the north-east Atlantic 51
5.2.1 Regional conventions and agreements 51
5.2.2 ASCOBANS 51
5.3 Existing EU legislation 53
5.3.1 Common Fisheries Policy 53
5.3.2 Habitats Directive 54
5.4 Proposed EU regulation on
incidental catches of cetaceans 54
6. Conclusions and recommendations 56
6.1 Significance of cetacean bycatch 56
6.2 Assessment and monitoring of fisheries 57
6.3 Proposed new EU regulation 58
6.4 Pelagic trawl fisheries 59
Figure 1: Schematic representation
of a pair trawl operation
25
Figure 2: Schematic model of the exclusion grid 40
Table 1: Pelagic trawl fisheries known or
suspected to catch cetaceans in the
NE Atlantic 25
Table 2: Details of French pelagic trawl fisheries
sampled during the 1994-95 study 26
Table 3: Comparison of catches between
pairs with standard tows and one
fitted with a selection grid and
associated experimental equipment
Appendix 1: Map of ICES fisheries areas
41
in the north-east Atlantic
Appendix 2: Details of the French
62
pelagic fleet for 1992
Appendix 3: Table of scientific names
63
of species referred to 64
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