Discards
Encyclopedia
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
which is not retained on board during commercial fishing
Fishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
operations and is returned, often dead or dying, to the sea. The practice of discarding is driven by economic
Economics
Economics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek from + , hence "rules of the house"...
and political
Politics
Politics is a process by which groups of people make collective decisions. The term is generally applied to the art or science of running governmental or state affairs, including behavior within civil governments, but also applies to institutions, fields, and special interest groups such as the...
factors; fish which are discarded are often unmarketable species, individuals which are below minimum landing size
Minimum landing size
The minimum landing size is the smallest length at which it is legal to keep or sell a fish. What the MLS is depends on the species of fish. Sizes also vary around the world, as they are legal definitions which are defined by the local regulatory authority...
s and catches of species which fishermen are not allowed to land, for instance due to quota
Individual fishing quota
Individual fishing quotas also known as "individual transferable quotas" are one kind of catch share, a means by which many governments regulate fishing. The regulator sets a species-specific total allowable catch , typically by weight and for a given time period. A dedicated portion of the TAC,...
restrictions. Discards form part of the bycatch
Bycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
of a fishing operation, although bycatch includes marketable species caught unintentionally. Discarding can be highly variable in time and space as a consequence of changing economic, sociological, environmental and biological factors.
Discarding patterns are influenced by catch compositions, which in turn are determined by environmental factors, such as recruitment
Recruitment
Recruitment refers to the process of attracting, screening, and selecting qualified people for a job. For some components of the recruitment process, mid- and large-size organizations often retain professional recruiters or outsource some of the process to recruitment agencies.The recruitment...
of small fish into the fishery, and social factors, such as quota regulation, choice of fishing gear and fishermen's behaviour. There have been numerous studies on the scale of discarding. In the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
the total annual quantity of discards has been estimated at 800,000–950,000 tonnes, or the equivalent of one-third of the total weight landed annually and one-tenth of the estimated total biomass of fish in the North Sea.
Impacts
Discarding impacts on the environment in two ways; firstly, through increased mortality to target and non-target species, particularly at juvenile life-history stages, and secondly, through alteration of food webs by supplying increased levels of food to scavenging organisms on the sea floor, and to sea birds. The survival of discarded fish and invertebrates is variable and depends on species and fishing gear used. For example, species such as the Pacific halibutPacific halibut
The Pacific halibut is found on the continental shelf of the North Pacific Ocean and Bering sea. They are demersal, living on or near the bottom. The halibut is among the largest teleost fish in the world. Halibut are strong swimmers and are able to migrate long distances...
caught in long-line fisheries in the Bering Sea
Bering Sea
The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves....
, or lesser spotted dogfish in beam trawls in the English Channel
English Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...
have survival rates of between 88-98%. Survival rates of roundfish discards are significantly lower, and this mortality is included in most ICES
International Council for the Exploration of the Sea
The International Council for the Exploration of the Sea is the world’s oldest intergovernmental science organization. ICES is headquartered in Copenhagen, Denmark, where its multinational Secretariat staff of 51 provide scientific, administrative and secretarial support to the ICES community...
stock assessments. Crustaceans are thought to be more hardy, though survival of crustaceans is variable; for instance, a survival rate of 25% is assumed for Nephrops norvegicus, the Norway Lobster
Norway lobster
Nephrops norvegicus, known variously as the Norway lobster, Dublin Bay prawn, or scampi, is a slim, orange-pink lobster which grows up to long, and is "the most important commercial crustacean in Europe"...
, whilst survival rates of almost 100% have been demonstrated for the hermit crab, Pagurus bernhardus
Pagurus bernhardus
Pagurus bernhardus is the common marine hermit crab of Europe's Atlantic coasts. It is sometimes referred to as the common hermit crab or soldier crab. It is about long, and is found in both rocky and sandy areas, from the Arctic waters of Iceland, Svalbard and Russia as far south as southern...
.
Discard policies
Discarding is a problem in all fisheries, and nations have adopted a number of measures to deal with the issue. The idea of banning discards is that since the fish that are discarded have a negligible chance of survival it is better from a managementFisheries management
Fisheries management draws on fisheries science in order to find ways to protect fishery resources so sustainable exploitation is possible. Modern fisheries management is often referred to as a governmental system of appropriate management rules based on defined objectives and a mix of management...
perspective that they are included in the fishing induced mortality
Population dynamics
Population dynamics is the branch of life sciences that studies short-term and long-term changes in the size and age composition of populations, and the biological and environmental processes influencing those changes...
figures on which allowable catch estimates are based.
Norway
The Norwegian Government introduced a ban on the discarding of some commercial species of fish in mid 1990. The initiative in Norway has been coupled with a comprehensive programme of monitoring and surveillance and a system whereby areas can be opened and closed when bycatch rates become excessive. The Norwegian system of attempting to reduce mortality of illegal fish is based on reducing their capture rather than reducing landing of "illegal" specimens.Canada
CanadaGovernment of Canada
The Government of Canada, formally Her Majesty's Government, is the system whereby the federation of Canada is administered by a common authority; in Canadian English, the term can mean either the collective set of institutions or specifically the Queen-in-Council...
has also instituted a ban on discarding at sea in its Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
groundfish fishery
Bottom trawling
Bottom trawling is trawling along the sea floor. It is also often referred to as "dragging".The scientific community divides bottom trawling into benthic trawling and demersal trawling...
that makes it illegal to return to the water any groundfish except those specifically authorised and those caught in cod traps. Authorised release is only considered for species that are known to have high survival rates on release or where there is no practical or nutritional use for a particular species. In addition to the banning of discards larger vessels are required to carry observers which would imply that there are now no illegal discards on these vessels.
Iceland
The introduction by the Icelandic Government of an Individual Transferable QuotaIndividual fishing quota
Individual fishing quotas also known as "individual transferable quotas" are one kind of catch share, a means by which many governments regulate fishing. The regulator sets a species-specific total allowable catch , typically by weight and for a given time period. A dedicated portion of the TAC,...
(ITQ) system of fisheries management across virtually all its major fisheries was followed by the introduction of a ban of at-sea discarding of catch. The Icelandic regulations require the retention of most fish for which quotas have been set or species for which a market exists. Since it is compulsory to land smaller fish but the government does not wish to encourage their capture, there are upper limits on the percentage weight of fish that can be landed below minimum landing size.
Both Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
and the Faroe Islands
Faroe Islands
The Faroe Islands are an island group situated between the Norwegian Sea and the North Atlantic Ocean, approximately halfway between Scotland and Iceland. The Faroe Islands are a self-governing territory within the Kingdom of Denmark, along with Denmark proper and Greenland...
have introduced similar regulations.
New Zealand
The quota management system in place in New ZealandNew Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
makes the discarding of most species of fish illegal. The ITQ system in New Zealand is complex system, and where fish are landed by a fisherman without quota for a particular species, they have the option to buy quota from another fisherman, or the value of the overrun catch be surrendered to the state. In many cases the fishermen find it easier to discard the fish at sea than go through the complex system of landing the fish and then making it legal.
There was a measurable increase in discarding immediately following the introduction of the ITQ system, despite the fact that fishermen were offered 10% of the market price for fish landed outside quota. In an attempt to address this change, the New Zealand Government increased the percentage of market price paid to 50%. The balance between offering an incentive to land discarded fish and the disincentive to catch fish over or outside quota limits is clearly a fine one, and dependent on the financial reward or penalty attached.