Fisheries Exclusion Zones – their use in Europe CEMARE, CEDEM, CNR-IRMA & SOC (SOTON) European Project VALFEZ (No. QLRT-PL ) Background to the study The use of exclusion zones as management tools in fisheries, for habitat protection and for species conservation has a long history in Europe. For fisheries management, their use is widespread and their popularity growing in the form of marine protected areas, fishing boxes and gear exclusion zones. It is clear that in some areas these zones have significant potential benefits with respect to species conservation, especially where low-migratory species are concerned, and to environmental aspects. However, with little published real analysis taking account of the links between the biology and economics, the economic benefits to fisheries are less clear. With the current levels of interest in exclusion zones, such modelling analysis is particularly pertinent to the debate being held in European fisheries management. This research project (VALFEZ), funded under EU framework 5, is examining the use and potential of exclusion zones in the management of fisheries in Europe. As part of this work, there are several case studies that we are examining which can be categorised as examples of where exclusion zones have been implemented, formally proposed or suggested. Three of the case studies discussed here which each fall into one of these categories respectively are: (i) the Gulf of Castellamare, Sicily; (ii) the Iroise Sea, Brittany; and (iii) the Sea Bass fishery in the English Channel. (i) The Gulf of Castellammare The Gulf of Castellammare is representative of a long standing fisheries exclusion zone in Europe, located in North West Sicily (Figure 1), where it has been in place for more than 10 years. In 1990 the Sicilian Regional Government imposed a year-round trawl ban in the Gulf of Castellammare, aimed at rebuilding the severely depleted demersal stocks and eliminating the conflict between the trawlers and the small-scale artisanal vessels operating in the Gulf. Currently, fishing within the trawl ban area is restricted to artisanal and recreational vessels. The artisanal fishery of the Gulf consists of some 96 small vessels operating out of 4 harbours. The main gear types and fishing methods are trammel nets, set gillnets, set longlines, FAD seine, squid jigging, and small-scale purse seining. Over 80 commercial varieties of fish are caught and sold locally, some of the more important being Red Mullet (Mullus barbatus), Picarel (Spicara flexuosa), Sea Bream (Diplodu. sargus, D. vulgaris and Pagellus spp.), Hake (Merluccius merluccius), Amberjack (Seriola dumerili) and Dolphinfish (Coryphaena hippurus) The artisanal fleet have experienced reduced gear conflict since the closure of the Gulf, but are still affected by: Recreational fishing, which since the mid 1990s has expanded rapidly and effectively filled the vacuum left by trawlers. Effort restriction in the form of a self-imposed vessel tie-up of 45 days per year. Figure 1: The Gulf of Castellammare, North West Sicily Effects of the trawl ban Biological data based on experimental trawl surveys and trammel net surveys show a large increase in demersal stocks since the ban was imposed (Figures 2 and 3). Of particular note is the increase of abundance of shallow water species, caught with trammel nets, of 77% between 1990 and 1999 (Figure 3). The biological frameworks for evaluation are well developed and results show that since the implementation of the trawling ban there has been at least a 7-fold increase in overall biomass of the Gulf. However, over the period species composition has changed, with most of the biomass increase being for varieties classed as only ‘moderately commercial’. This may therefore have attenuated the financial gains for artisanal fishermen. Experimental survey work has examined biodiversity and catches from various areas both within and outside of the reserve. This will enable a spatially explicit level of modelling to be developed. It will be possible to model the Gulf fisheries to the level ports and harbours. Biologically the model will focus on those species that are the most valuable commercially: two species that dominate in the displaced trawl catches and two that are targeted by the remaining artisanal fleet. Work is being undertaken to examine and develop length-based and age-based relationships for these four species. The final evaluation technique used in this case study will depend upon the quality and reliability of this biological data. Figure 2: Changes in demersal stocks (trawl survey results) Figure 3: Changes in demersal stocks (trammel net survey results) (ii) The Iroise Sea This case study represents an official French government project aimed at ecosystem protection in an open coastal sea where biodiversity is particularly rich. It is anticipated that any closure will have important consequences for fisheries management, recreational activities and ecotourism. The strategy is to create a national park in the Iroise coastal sea (west of Brittany) an area included in the UNESCO world network of biosphere reserves for its remarkable biodiversity. The area supports a large number of human activities, including commercial fishing (mainly using nets, pots and lines), seaweed harvesting (Laminaria digitata figure 4) (90% of French production comes from the Iroise) and various recreational activities (sport fishing, diving, sailing, ecotourism). Approximately 500 professional fishermen and seaweed harvesters work in the area (most of them on boats under 16 m.). The number of recreational boats sheltered in the marinas and small ports of the Iroise is about 2500 and, according to a recent survey by IFREMER, 40% of the owners of these boats are recreational fishermen. The area is frequented by more than 5000 underwater fishers and with regards to tourism, more than tourists visit the islands of the Iroise sea each year. Some modelling work has already been carried out within the area and a bioeconomic model adressing some of the problems associated with implementing a fishing exclusion zone in the Iroise sea has been presented by Boncoeur et al. (2000/1). This model is mainly theoretical (and based on the Hannesson model – Hannesson 2000) and while its basic assumptions are qualitatively suited to the situation in the Iroise sea and to questions raised by the creation of a marine national park, the model lacks a real quantitative basis at present. However the model is being developed to incorporate real data. Figure 4: the sea weed Laminaria digitata (iii) The English Channel Bass Fishery This case study examines a hypothetical exclusion zone in the English Channel, the aim of which is to protect the spawning aggregations of the Seabass (Dicentrachus labrax (figure 5)). The English channel winter fishery has historically been prosecuted by French fishing vessels. However, recently, with growing demand in other European countries, a multi national fishery has developed. Despite this there has been a long-standing artisanal fishery for bass in the UK along the English Channel characterised by small vessels and low intensity fishing. Over the past decade, however, there has been a dramatic increase in the fishing effort applied to Seabass in the English Channel exacerbated by the increased use of and move towards mainly pair trawl gears. The species is highly suitable for inclusion in this study, being of very high value and being prosecuted in a single species fishery with very little or no interaction with other fisheries in the Channel. In addition there have been for some years now, calls for restrictions on commercial landings. The species falls outside EU quota regulations although in the past two years both the national governments of France and the UK have implemented strict landing controls. There has been some significant bioeconomic modelling work done on the English Channel fisheries recently (Pascoe 2000). As a key species in the English Channel, Sea Bass was included and modelled in age-structured form. Modelling work within VALFEZ will use this existing work, to analyse potential management effects on bass within the English Channel fisheries as a whole. Further, a separate single species model will also be considered. This model being developed is to be an inter–temporal, spatially explicit, age-structured bioeconomic simulation / optimisation model. Through the modelling process the fishery will be examined at the level of homogeneously grouped ICES rectangles. Full data has been collected on commercial landings of the fish over a ten year period, the biology is very well known, with work being done by Picket and Pawson in the early 1990’s recording extensively the biology of the fish. Figure 5: The Sea bass (Dicentrachus labrax) For further information, contact; Carl James CEMARE Department of Economics, University of Portsmouth, Locksway Road, Portsmouth, PO4 8JF, UK References Pascoe, S. (ed.) Bioeconomic modelling of the fisheries of the English Channel, FAIR CT , Final Report. Pickett, G. & Pawson, M. Sea Bass: Biology, exploitation and conservation, Chapan and Hall Fish and Fisheries Series Boncoeur et al Costs and Benefits of implementing a marine reserve facing prey-predator interactions, Conference on the Economics of MPAs 6-7July 2000, Vancouver, Canada Hannesson (1998) 'Marine Reserves: What Would They Accomplish ?' Marine Resource Economics 13: