Discarding occurs because most methods of fishing catch more fish than the fisherman can legally land and sell. Therefore any commercial fishing activity will result in discarding of unwanted catch. Discards can be defined as that portion of the total weight of undersized, un-saleable or otherwise undesirable whole fish discarded at the time of capture or shortly afterwards.

The Marine Institute, working closely with DCMNR and Industry, compiled information on the distribution and abundance of eggs and larvae, juvenile and adult fish in the waters around Ireland and presented these data to the EU Commission. This presentation was powerful evidence of the biological importance of this area. In 2003 the EU Commission established a “Biologically Sensitive Area (BSA)” off the south west of Ireland. In 2003, the EU also established a specific fishing effort regime inside the BSA and outside the BSA for demersal fishing vessels as well as scallop and crab fisheries.

In order to manage a stock effectively it is very important to understand the dynamics of that stock. Three critical pieces of information required to manage any fishery properly are: (1) Location of spawning areas; (2) Timing of spawning seasons; (3) Estimation of size at maturity. This information can be obtained by studying the spawning patterns of a stock. This type of data was vital in the Irish Sea cod recovery programme (the closure of the Irish Sea box from February to May of this year). This area represents a large spawning ground for the Irish Sea cod and the closure was to protect the spawning adults.

The quality of the international stock assessments carried out by scientists are directly linked to the quality of the fisheries data they use. In recent years, scientists have expressed great concern over the poor quality of catch data from most of the important fisheries in the EU area. Although scientists have been struggling with the problem for many years, the problem has become more acute in recent years. In 2005, it was not possible to carry out stock assessments for a number of key stocks in EU waters (including the waters around Ireland) because of the poor quality of the catch data. The issues of ‘misreporting and discarding’ are now a serious problem for the scientific community and need to be urgently addressed.

Ecosystems are composed of living animals, plants and non living structures that exist together and ‘interact’ with each other. Ecosystems can be very small (the area around a boulder), they can be medium sized (the area around a coral reef) or they can be very large (the Irish Sea or even the eastern Atlantic). One of the first tasks marine scientists must decide on is to define the boundaries of the ecosystem they want to look at (e.g. is it Dublin Bay? the Irish Sea? the north east Atlantic?). Once the ecosystem we are interested in is defined then we can think about how this part of the ocean should be managed. This must be agreed by consensus with all the stakeholders (users of the ecosystem).The idea here is that we are managing an ecosystem with many users not just a fish stock exploited by fishermen.

The Marine Institute monitors the levels of priority hazardous substances in a range of commercial fish species landed at Irish ports and also in shellfish from selected sites around the Irish coast.

The term deepwater refers to fishing in waters greater than 400m depth. The main species taken in these deepwater fisheries are roundnose grenadier, black scabbard, orange roughy, greenland halibut, tusk and deepwater sharks. The fisheries take place in depths between 800m and 1200m on the slopes of the Porcupine Bank and in the Rockall Trough to the West of Ireland. France was the first country to take an interest in deepwater stocks in the late 1980s. Since then Spain, UK Norway, Faroes and Ireland have developed deepwater fisheries. On the slopes west of Donegal, Norwegian long-liners fish for ling and tusk on the shelf edge. On the slopes of the Porcupine Bank Spanish longliners and gillnetters fish for shark. Further out in the Atlantic trawlers from many countries fish the Mid-Atlantic Ridge and the Hatton Bank.

The waters around Ireland contain some the most important spawning areas for north-east Atlantic fish stocks. Egg and Larval Surveys are a vital part of mapping these spawning areas and contribute to fisheries management decisions. Egg surveys can also give scientists an indication of the state of the spawning stock within a particular area by using what is called the Annual Egg Production (AEP) method. This method uses information on the number of eggs sampled in an area, and relates it to the number of eggs produced by female fish in the spawning season, to calculate the number of females spawned in the area.

Nephrops norvegicus, also know as Dublin Bay prawns and Norwegian lobster, are the second most valuable species fished by the Irish fleet. In 2002 landings were worth almost €28 million. Nephrops are also a very important species for the processing industry in Ireland that use prawns to produce the value added product 'scampi'. Marine Institute scientists have spent many years researching the biology and stock dynamics this commercially important species. Nephrops is a widely distributed species but despite its common name, the “Dublin Bay Prawn”, this species is not found in Dublin Bay. It is found, however, in the Irish Sea, the Celtic Sea and off the West Coast of Ireland. It is also found from Iceland to Morocco and into the Mediterranean as far as Egypt, occurring at depths from 15m to 800m.

The Marine Institute (MI) undertakes monitoring and research relating to contaminants and chemical residues in Irish fisheries products, and works with key agencies such as the Food Safety Authority of Ireland (FSAI) to ensure a high level of consumer protection. In 2004 the MI carried out a study of levels of brominated flame retardants, (BFRs), in Irish farmed salmon.