Analyse des petits pelagiques, sardine et anchois, dans le golfe de Gascogne

Since 1993 the yearly amounts of sardine landings for the Bay of Biscay fishing ports have experienced a constant increase (10,000 tonnes in 1993); on that account sardine is the first species landed in the fishing ports of the Bay of Biscay (15,000 tonnes in 2003). It is sold 0.54 € / kg (constant price over ten years) which means a 8,100 k€ turnover in 2003 and the 12th rank in value landed in the fishing ports of Bay of Biscay. Though anchovy landings have decreased over the last ten years, especially since 2001, this species occupies the 3rd rank of the highest landings (7,300 tonnes) of the Atlantic shoreline in 2003.The decrease of anchovy landings over the last ten years may account for the high increase of its constant sale price of 1.5 € / kg from 1993 to 2001, while it reached 3.5 € / kg in 2003. The total value of anchovy first sales price reached 25,400 k€ in 2003, which places the species at the 5th rank in value of the landings in the Bay of Biscay. Almost all of the sardine landings for 2003 were achieved by boats of South Brittany (Saint Guénolé, Douarnenez) and Loire Country (Saint Gilles Croix de Vie) accounting respectively for 80% and 17% of the species landings for all the fishing ports of the Bay of Biscay. In the past, before 1997 both these countries contributed in a same proportion (50%) to the sardine landings. Since then the production of sardines for South Brittany has doubled in weight, this accounting for the current importance of this country. It is worth mentioning that sardine greatest landings occur from June to November (85% of the landings); this concerns 77% of class 10 sardines (big size sardines). The fishing boats from Loire Country (La Turballe, Saint Gilles Croix de Vie) contribute as high as 77% in weight of the anchovies, while South Brittany (Saint Guénolé, Lorient) and Aquitaine Country (Saint Jean de Luz) each contribute to 10% of these landings. This regional sharing of anchovy landings has only slightly increased over the past 10 years. 80% of anchovy captures are achieved from June to October; they consist of 56% class 20 anchovies and 37% class 10 individuals. The French fleet fishing sardine and anchovy in the Bay of Biscay involves two métiers : Purse seiners : mostly located in the region of Pont L'Abbé and in the area of Bayonne (quartier maritime), these account for 85% of sardine landings in 2003. This results from an increase, since 1996, in sardine landings by the purse seiners to the detriment of the pelagic fleet, whereas up to that date purse seiners and pelagic trawlers each contributed for half of sardine total landings all fishing ports taken into account. Concurrently, there are more purse seiner boats fishing sardine and thus 35 boats — mostly ranging between 12 and 17 m long — contributed to the landings of the Bay of Biscay in 2003. It is to be noted that the purse seiners involved in sardine fishing have not only gained in length over the last ten years (15.38 m in 1993 against 16.25 m in 2003) but also tend to modernize. The purse seiners only weakly contribute to anchovy landings in the Bay of Biscay with 5% in weight of anchovy landings in 2003. In fact their contribution to the landings never exceeded 10% over the last ten years. The captures vary from one year to the other mainly owing to the behaviour of the schoals which can not always be reached easily by the seiners. 18 seiners fish anchovy over the third term off Saint Jean de Luz coast. The other French seiners fish when the opportunity arises, especially those from South Brittany in autumn. The midwater pair trawlers (non exclusive), mainly coming from Saint Nazaire and Sables d'Olonne, capture most of the anchovy landed in one year (95% of the landings for all the fishing ports of the Atlantic shoreline in 2003). They start fishing in January/February off Oleron (at the boundary of divisions VIII a and VIII b). During the second term they mainly fish south of the Bay of Biscay; the landings mainly concern Saint Jean de Luz. Once the fishing season over from end of March to end of May, the fishing fleet moves north off Brittany coast (at the boundary of divisions VIII a and VIII h) at the end of summer and beginning of autumn. Late fishing takes place south of the Bay of Biscay from October onwards. Some fifty midwater trawlers of 17 m and more are involved in this fishery ; they each fish over 50 tonnes a year. Since 1987 anchovy is subject of research studies and thus a minimum of information is available on the stock. The anchovy natural mortality is high, though it has decreased since 1997. The recruitment observed in 2002 and 2003 remain weak and the spawning stock biomass reached in 2003 its weakest level over the fourteen last years. The minimal size of landings has been fixed to 12 cm by the EU. The captures are limited by an annual TAC which is of 33,000 tonnes since 1995 for divisions VIII a and b, which means a quota of 3,300 tonnes for France and 29,700 tonnes for Spain according to the apportionment rule built up according to the historical captures of both these countries. Thanks to an exchange of quota the French fishing capacity is 13,000 tonnes. The recent recruitment (mainly that of last year) contribute to the major part of the exploitable biomass. The predictions are mainly based on the hypothesis regarding the future recruitment. Management in terms of an annual TAC seems most inadequate for this kind of species. From one year to the other the TAC could be adapted to the abundance of the stock if only the recruitment could be predicted in a reliable way. If technically possible, TAC adjustment along the year as a function of the availability of information on the level recruitment rises economical and political problems. Another way of management would consist in defining areas and periods of the year for sardine and anchovy fishing as a function of their way of live so as to spare as much recruit as possible before laying. Both these possibilities are subject to investigations by Ifremer and AZTI scientists as part of ecological studies on sardine and anchovy.