Acronym NA
Category
Fisheries
Title Technical solutions to mixed fishery problems Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Dick Ferro Coordinator email enquiries@marlab.ac.uk
Coordinator institution
FRS - Fisheries Research Services (United Kingdom)
Institutions involved
NA
Start year 2003 End year 2007 Funding (€) € NA Website NA Summary Scottish towed gear demersal fisheries typically catch a number of different species. Some stocks are exploited outside safe biological limits and are subject to Stock Recovery Plans formulated by the European Commission. In a mixed fishery the different species may mature at different ages and have widely different growth rates. Any increase in mesh size to improve the exploitation pattern of larger, faster growing species (such as cod) will catch fewer of the smaller species, such as haddock and whiting. There are various management strategies to overcome the problem of mixed fisheries. It may be possible, e.g. by acoustic means, to identify areas in which one species predominates and, through a by-catch ban, force fishermen to work only in these areas. However, this may be of limited application, would be restrictive and therefore unpopular with the industry. A pragmatic option is to allow fishing if particular gear designs are used which address the need for individual selection processes for individual species. This can be done by separating the species during the fishing operation. Previous research has indicated species-specific behaviours and physical capabilities of fish which make these ideas feasible. Such a strategy has been implemented e.g. in shrimp fisheries in many parts of the world. Previous research indicates that each fishery and fishing gear may require a different mechanism to optimise species separation. A summary of the state of the art is available and highlights the current options for separation within mobile gears, such as raised footrope, horizontal separator panel, square mesh panel, inclined panel, rising ropes and grid. An innovative feature of the project will be the possible application of combinations of these devices to provide effective solutions. A review will be undertaken to assess which species are to be separated and what selection mechanisms will subsequently be applied to each. Only one gear will be developed for each fishery. An EU contract (C739 starting in November 2002) considers three of the main fisheries catching cod in the North Sea and West of Scotland areas - whitefish ottertrawl, flatfish beam trawl and Nephrops trawl. The role of FRS in this project is to develop an ottertrawl which separates cod from haddock/whiting into different codends and applies different selective processes to each. Flatfish (such as lemon sole) may also need to be separated from cod in this fishery. There is also a need to develop a method to separate Nephrops from whitefish (roundfish and flatfish) and to improve the size selection of Nephrops. Preliminary studies recently carried out by FRS in the North Sea and Irish Sea have looked at grids and panels to separate these species and this work will be continued under this ROAME. Initial behavioural studies will be undertaken to assess species-specific behaviour. Developing observation technologies using a combination of underwater television and multi-beam sonar will be applied to give quantitative information on behaviour throughout the trawl which was not previously available. Prototype gears will be developed, using models in a flume tank if necessary. Further behavioural studies will be used to check the separation and selection mechanisms of a prototype gear. Sea trials will then be conducted on final designs on commercial vessels to make quantitative assessments of the separation and selection as well as practical assessments of the operation of the gear. The fishing industry (e.g. netmakers) will be invited to participate in the project. Existing forecast models for predicting the effects of gear selectivity and fishing mortality changes will be developed to incorporate spatial and seasonal effects. The gear selectivity component will be developed further to operate according to fleet/area/time subscripted length-based processes prior to age conversion. The forecast model will comprise the main element in the theoretical evaluation.
Keywords
Fish;
Sole;
Fishing technology;
Shellfish;
Gear technology;
Crustacean;
Haddock;
Cod;
Gear selectivity;
Lobster;
Flatfish;
Trawling;
Marine Region
26
Northwest Coast of Scotland and North Ireland (27.VIa)
5
Southern North Sea (27.IVc)
6
Central North Sea (27.IVb)
13
Northern North Sea (27.IVa)
4
Marine Region Map
