Discards and Bycatch in fisheries: information sheet
Introduction
The Marine Conservation Society (MCS) was established in 1983 with the aim of protecting the
marine environment for wildlife and future generations. MCS is the only national environmental charity
working exclusively on the range of issues affecting the marine environment.
The MCS fisheries programme aims to promote ecologically sustainable fisheries and
mariculture to protect fish stocks, livelihoods and marine life.
Our approach involves three main strands:
 Influencing fisheries and mariculture policy, management and practice.
 Promoting individual responsibility and consumption of sustainable seafood including wildcaught and farmed fish through the Good Fish Guide, Fishonline www.fishonline.org, and the
Pocket Good Fish Guide.
 Raising public awareness of the issues surrounding fishing and mariculture.
What is the issue with discards & bycatch?
Many fisheries are non-selective –catching animals that they did not intend to. This non-taget extra
catch is known as ‘bycatch’. Of these bycatch species, some have a commercial value and are
brought back to land by fishers to be sold. However, a large proportion is unwanted and so is
discarded-thrown back over the side of the boat.
What is the difference between discards & bycatch?
In fisheries, the terms ‘bycatch’ and ‘discards’ are used interchangeably, however we can classify
catch into a number of categories:
Target catch- species which the fisher intended to catch and are brought back to land and sold.
Bycatch- Species that are caught accidentally. Bycatch can be split into two further categories:
Valuable bycatch consists of species that can legally be brought back to land (the fisher has a
quota or there is no quota) and sold because it has a market value. Fishers often just use the term
‘bycatch’ to refer to such species.
Discards are the proportion of bycatch (caught accidentally), which is thrown back overboard,
because it has no value or cannot be bought back to land for legal reasons- this can include
juveniles of the target species. Confusingly conservationists often use the term bycatch to refer to
non-fish species caught, particularly marine mammals and seabirds, and discards as fish species
caught and thrown away. But in fact most of these species are in fact discards (i.e. you can not
catch a seabird and then bring it to land to sell).
Diagram courtesy of JNCC
What are the causes?
There are a number of reasons for discarding fish:
 The fish has little or no market value- this could be because it is not a commonly eaten species, or
because it has been damaged so is worth less money.
 Due to management regulations- a number of rules designed to protect the fish can often result in
more discards. Fish may not be allowed to be brought to land because they are small juveniles, or
because there is not enough quota left for the fishery.
 A combination of both of these reasons is a practice called ‘high grading’- this is where
fishermen throw away fish, which has a market value, but the value is not as high as the same
fish of a bigger size or better quality. This occurs when fishers do not have much quota left, so to
maximize their profits they only keep the fish that fetch the highest price and throw the rest away.
Why is it a problem?
Most of the fish that are discarded back into the water do not survive, so it is an appalling waste of a
natural resource: it is a major threat to the health of fish stocks, and to the future of the fishing
industry. Discarding undermines the conservation policy, a cornerstone of the CFP (European
Common Fisheries Policy), by killing of fish without making any economic returns.
Capture and discarding juvenile individuals of target species results in lower catch opportunities for
those species in the future (hence future income is reduced) and a reduction in future spawning mass
(egg producing fish) for the future. Discards of mature fish both waste resources in the short term and
reduce the amount of adult fish, which would otherwise have been available to reproduce in the future
and maintain a health fish population.
The capture and discard of fish, crustaceans, seabird or sea mammal species which are not targeted
by fisheries, is an unnecessary negative impact on the marine ecosystem as it affects its functioning
and biodiversity negatively, without providing any benefits to society. It can also undermine the aims
of international agreements such as the Convention on Biological Diversity
Certain marine organisms, including some species of sharks and rays are very sensitive to fishing
and may as a result, be reduced to very low levels even when they are only caught as unwanted bycatch. In such cases, the killing of just a few individuals may be critical from a biodiveristy perspective
and may prevent the urgent recovery required of these populations (as required in international law
for some species under the Convention on International Trade in Endangered Species).
It is very difficult to estimate the amount of discarding as in most countries it is not mandatory to
report how much you have caught and then discarded. This exacerbates the problem not only of
discarding but also accurate stock estimates; scientists have to conduct discard sampling surveys
and extrapolate those results in order to calculate how much fish is left in the sea and thus how much
can be taken out. The lack of discarding reporting means that these estimates are very uncertain and
it is possible there is a lot less fish in the sea than estimated, which becomes an even bigger problem
when total allowable catches are set based on these estimates.
To give an idea of how much fish is discarded, in 1998 UK North Sea whitefish trawlers discarded
cod, haddock and whiting worth € 75 million, equivalent to 42% of the value of their landings.
What are the solutions?
There are two issues to be solved here- reducing overall bycatch (including valuable proportion as it
is accidentally caught) and eliminating discards. The only way to address these problems is not to
look at “what to do with the discards/bycatch” but to prevent these unwanted species being caught in
the first place.
Returning unwanted by-catches back into the sea does not reduce the problem because most
species of fish and crustaceans will be dead or have low survival in the sea after having been caught
and then discarded.
As with all fisheries issues there is no –one size fits all solution so it is important that we use a variety
of measures from our ‘toolbox’, with regards to discards and bycatch the most important element is to
take an ecosystem based approach to fisheries management and to adhere to the precautionary
principle. Specific measures to reduce bycatch and discards include:
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Use and development of species selective gear.
Technical conservation measures to improve gear selectivity.
A compulsory requirement to record all discards in EU logbooks and that priority be given
to assessing discard rates during routine inspection by fishery inspectorate officers.
The use of closed areas- such as the real time closures to protect juvenile and spawning
fish.
Alternatives to current marketing strategies to reduce waste and eliminate commercial
practice of ‘High-Grading’ including a review of the ‘withdrawals system’ and ‘intervention’
mechanisms.
Multiple-species quota arrangements for mixed demersal fisheries.
Carefully considering a future ban on discards- this puts a cost on unwanted by-catch,
thus motivating development of technologies and practices, which will catch fewer
unwanted fish. It must be ensured that the profit from selling discards does not go back to
the fishermen but instead into enforcing the discard ban and it essential that fish which are
landed but would normally be discarded because they are undersized do not enter the
market, but rather are used for fishmeal for example
Increased use of observers to help with discard monitoring
Electronic log book schemes- real time reporting of catch composition- especially where
Real Time Closures are considered
Monitoring and control of fishing gears
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Encourage consumers to diversify their seafood diet by traying more sustainable
altneratives to relieve the pressure on the traditional main species
References:
COMMUNICATION FROM THE COMMISSION TO THE COUNCIL AND THE
EUROPEAN PARLIAMENT A policy to reduce unwanted by-catches and eliminate discards in European
fisheries
http://www.jncc.gov.uk/page-1563
Discarding in fishing: making sense of a complex issue. Seafish industry authority factsheet 2009