The humane killing or slaughter of commercially harvested fish requires that fish are carefully handled and effectively stunned (causing immediate insensibility) and bled out rapidly after capture.
Most commercially-caught wild fish that are alive when landed die either from being left to suffocate in air, or by a combination of suffocation and evisceration (gutting) during processing. These methods take from minutes to hours to induce insensibility, can cause significant suffering and are not regarded as humane.
Percussive stunning and electrical stunning methods offer some potential to improve the humaneness of commercial fishing. Percussive stunning, which involves a forceful and accurate blow to the head, is most commonly used for manually killing small numbers of fish. In commercial fishing, where large numbers of fish need to be rapidly killed, there may be a place for automatic percussive stunning devices that have been developed for fish farming.
Where percussive stunning is not practical or suitable, electrical stunning methods also developed for fish farming may provide an alternative, however there is a continuing need to improve the humaneness of current methods for the capture and killing of fish. The RSPCA strongly supports further research and development in this area.
In addition to the intended harvest, commercial fishing methods can result in the capture and injury or death of many non-target species including crustaceans, fish, turtles, and marine mammals. This non-target capture is known as bycatch and is the cause of significant suffering in captured animals as well as having a serious conservation impact.
Measures to reduce bycatch include avoiding drift net or long-line fishing methods, the regulation of minimum standards for the design and use of fishing nets and the uptake of modifications such as escape mechanisms or the use of circle hooks.
More information on the welfare impacts of commercial fishing is available from the fishcount.org.uk website.
Information on activities to reduce bycatch is provided by WWF at its Threats/bycatch website.
Information on national government strategies to reduce bycatch is available at the Department of Agriculture website: http://www.agriculture.gov.au/fisheries/environment/bycatch
Sustainability of commercial fishing
Another serious problem associated with commercial fishing is overfishing, which threatens the sustainability of many wild fish populations. The Australian Marine Conservation Society has developed an online guide to sustainable seafood – Australia’s Sustainable Seafood Guide – in response to growing public concern about overfishing and its impact on our oceans.
You can also read about the work that WWF is doing to improve the sustainability of Australian fisheries here.