Discards - Unwanted catch


Discards - Unwanted catch

This dossier presents Wageningen University & Research's ongoing research and its results in relation to discards (unwanted catch) of the Dutch fishing sector. This topic has become ever more important in relation to the new EU measure known as the ‘discard ban’, aiming at curtailing the practice of discarding.

What are discards?

When fishermen go out to sea, they not only catch the fish aim for (full-size, commercial ‘target fish’), but also other species of fish, undersized fish and benthos (e.g. crabs and starfish). The untargeted but commercial fish is landed but the rest is returned to the sea. The latter is commonly known as discards or unwanted catch.

Why throw them back?

There are a number of reasons for discarding. It goes without saying that if a fisherman is allowed to sell his catch and expects to get a good price, he will not throw it back into the sea. In other words, fishermen have to navigate between two determining factors: regulations and the market.

The main reasons for discarding are:

  1. The catch is of little or no value. For example: we do not eat starfish; there is only a limited market for dab, which affects the price (supply/demand), Europeans do not eat jellyfish (unlike the Japanese) – so there is no market for them here;
  2. The catch is damaged;
  3. The catch may not be landed because:
    1. The fish are too small (there are legal minimum sizes);
    2. The fisherman has reached his quota for that species;
    3. There are rules about the catch composition per 24 hours;
    4. The fish is a protected species (e.g. sturgeon or certain species of shark);
  4. Fishermen sometimes throw fish of a certain size back because other sizes are more profitable (particularly important if the quota are tight). This practice is known as high grading and is illegal.

If a fisherman is able to catch only the fish he wants to catch, he will be fishing selectively. Selectivity depends on a number of factors, including fishery technology, fishing methods, size of the mesh, target species, season, weather, fishing area and the fisherman’s own behaviour (choice of fishing area, for example). This means that selectivity within a fishery is variable.

Landing obligation

In June 2011, the European Commission put forward a proposal to introduce a landing obligation. The main reason for this was that discards were seen as a wasteful practice. Since then, the European Council of Ministers and the European Parliament have been negotiating about how best to put this proposal into practice. In February 2013, the European Parliament and the European Council voted in favour of a landing obligation (discard ban).

The EU expects that banning the discarding of commercial species regulated by quota will steer the fishing industry towards innovations enabling them to fish more selectively. The EU also hopes that fishermen will put their knowledge of discards (and how to avoid them) to better use. Changing fishing behaviour with existing vessels and gears, developing new fishing techniques, and fishing in other areas or at different times should result in less discards. The European Union therefore expects that this landing obligation will ultimately result in a more selective fishing industry, a reduced ecological impact and improved fish stocks.

The EU will introduce the landing obligation in phases: it is expected to be applicable for pelagic stocks from 2015 and to demersal stocks from 2016. The landing obligation does not mean that all discards must be brought ashore: only specific commercial species regulated by quota will have to be landed.


The details or implications of these new regulations are yet unknown. They will be worked out during the course of 2013.

Questions that have arisen are:

  • Procedures onboard will have to change. What changes will need to be made and how will these affect the fishermen?
  • The current quota limit the amount of landed fish, the new system will have to take undersized fish into account too. How will this work?
  • If fishing quotas are changed, will this affect the relative stability (agreements between EU countries about fixed distributions of total allowable catches)? After all, not all countries and fisheries have the same amount of discards.
  • How will the new measure be controlled? Will more checks be carried out and will cameras be fitted onboard?
  • The problem of unwanted catch will never be completely resolved in mixed fisheries. Landing fish that otherwise would have been returned in sea, includes fish that possibly would have survived. In the regulations there is mentioning of exceptions for fish with a high chance of survival. It is yet unknown how this will work out in practice.

It is still too early to say how the new regulations will affect the Dutch fishing industry. What we can say, however, is that it will have a particular strong impact on the Dutch demersal fishing sector. In this mixed fishery catches contain many different species in one haul.

Research into discards and the landing obligation

Wageningen Marine Research carries out ongoing research into discards on behalf of the Ministry of Economic Affairs. Discards have an effect on fish stocks and the eco system. Some stock assessments take the number of discards (plaice, flounder and cod, for example) in account. Thus research of catch compositions of the Dutch fleet is part of Wageningen Marine Research' work. The research is conducted at sea, on board of commercial fishing vessels.

Wageningen Marine Research traditionally collects its data via observers, Wageningen Marine Research' staff joining the crew of a fishing vessel taking samples of the catch and registering species, length and age compositions.. In addition to the observers, since 2009 fishermen themselves have been taking samples of discards. Every week, 3-5 vessels monitor their catch and supply samples. The samples are processed and analysed by Wageningen Marine Research. This cooperation has provided a better overall picture of the temporal and spatial variation.

In addition, in view of the forthcoming landing obligation, Wageningen Marine Research (together with Wageningen Economic Research) participates in a number of projects exploring the effects of this obligation in relation to management (setting quota), fishing practices (e.g. processing catches) and research (e.g. monitoring).

Research on discards

News about discards