About the welfare of wild caught fish

The Dutch Foundation for the Protection of Fish is concerned about the welfare of wild caught (sea)fish. According to the Foundation, more than a billion fish worldwide are being exposed to serious welfare violations during fishery procedures. Public awareness and the development of a fish welfare label might contribute, according to the Foundation, to a fair possibility for consumers to choose consciously for fish products with less associated welfare violations.

For that purpose, the Foundation for the Protection of Fish has asked the Science Shop of Wageningen UR to support her with student research. The research in this project aims to support the Foundation in moving forwards towards the development of a fish welfare label.

Nineteen students (3 student teams and 2 master students) did research for the Science Shop in the field of a) welfare of (flat)fish in relation to catching procedures and stunning/killing procedures of wild caught (flat)fish and b) on agenda-setting of the subject of fish welfare and a fish welfare label. Through literature study it was concluded that scientific arguments support the notion of fish sentience and suffering. Analysing the scientific evidence in this respect, Elder (2014) concluded that “.....for those unconvinced in light of both scientific and popular consensus, the precautionary principle, where we treat fish as if they may suffer, will ultimately be advocated as an appropriate approach for fish welfare”.

When flatfish are caught at sea, they are driven together in a net, sometimes dragged and compressed for hours, taken out of their natural habitat by bringing them on board before they finally die due to oxygen insufficiency, freezing on ice or being eviscerated. Survival analyses of discards during beam trawler fisheries, indicated that only 14% of the soles (Solea solea) survive a period of 91 hrs, while only 48% of the plaice (Pleuronectes platessa) survive a period of 77 hrs when placed into a survival tank directly after being brought on board. All examined whiting (Merlangius merlangus) and pouting (Trisopterus sp.) died, while survival was higher for cod (Gadus morhua) (66% /88 hrs) and skates (Rajidae) (72% /80hrs) (Depestele, 2014). Although survival values for adult individuals are expected to be higher, the results illustrate that welfare is at risk during catching procedures.

Burying behaviour of sole (Laan, 2015)
Burying behaviour of sole (Laan, 2015)

The following fisheries related risk-factors for fish welfare can be distinguished: 1) net material and mesh size; 2) hauling duration; 3)hauling speed; 4) (speed of) bringing up the net; 5) fishing depth; 6) the amount of stones and debris in the net; 7)catch size; 8)bringing fish on board ; 9) handling of fish; 10) killing and/or stunning method; 11) the amount of discards. In the Netherlands, flatfish fisheries are traditionally the domain of the beam trawler fishing industry. At present this way of fishing is rapidly being replaced by modern and more sustainable fishing methods like pulse trawling, pulse wing, sum wing, twin rig, fly-shoot and hydro-rig. Some of these fishing methods might be expected to impose less fish welfare problems. However a systematic evaluation of ecologically sustainable fishing innovations from the perspective of fish welfare has thus far not been carried out.

There are indications that shelf life of fish products, for certain fish species, may increase with decreasing amounts of injuries. The latter implicates that measures to improve aspects of fish welfare may possibly increase profitability of fisheries business management as well. Survival chance or “vitality” is considered a welfare indicator with content validity. Survival studies on board of a fishing ship however, are technically difficult and labour-intensive. Proxy’s such as the Damage Catch Index (CDI), the RAMP-test (RAMP) and species specific behavioural indicators for flatfish (camouflage behaviour and burying behavior) as investigated in the underlying study, do have low predictive validity for survival thus far (Chapter 6.3). In addition, species-specific coping capacities for different stressors require different proxy’s for vitality for different species. Thus far, the lack of reliable welfare indicators therefore prohibits detailed predictions about the contribution of different separate fishery related risk factors to species specific violations of fish welfare.

Three factors can be distinguished that may facilitate the development and implementation of a welfare label: 1) public awareness about fish welfare issues; 2)acquaintance with innovations from within the fisheries sector (like the fishery initiated innovation of stunning methods on plaice in the Netherlands ) and 3) the development of reliable and validated certification procedures. For all three factors, collaboration between NGO’s, frontrunners of innovation from the fisheries sector and scientific community play a crucial facilitative role. Therefore, as a final step in this project, a student team will organise a dialogue meeting to officially end the underlying project and make a start with such meetings.

Recommendations:1. National and European policy, NGO’s and fisheries industry work hard to realize a more ecologically sustainable fisheries industry. In light of the increasing public awareness about fish welfare however, it seems important to incorporate considerations about fish welfare into these sustainability goals.

2. Taking the precautionary principle as a starting point, it is recommended to decrease the impact of risk factors for fish welfare in the fisheries industry. To this purpose, meetings between NGO’s, fisheries industry and scientific community are a prerequisite.

3. Factors that have a positive impact on both fish welfare and product quality and/or fisheries industry management deserve attention.

4. In order to facilitate the development and implementation of a fish welfare label, research investment in reliable, validated and easy to measure welfare indicators is required.

5. In order to implement fishing methods with more consideration for fish welfare, it is important to strive for synergism with fisheries business management.