Aménagement des pêcheries côtières de Nord-Bretagne, algues-crustacés

Today, the seaweed industry's main products are the alginates and carraghenanes. The industrial network faces many problems. However, it remains prosperous since it ranks fifth in the world for alginate production and third for caraghenanes'. This stability which seems safe on a middle term standpoint must not conceal the crisis which previously hit Fucus' exploitation. Rightly so, being harvested until approximately 1950 for soil amendment purposes, coastal kelp (i.e. Fucus), was replaced by chemical fertilizers. Brittany's production which was reaching 180 000 cubic metre in the twenties, close to 200 000 tons of fresh kelp, would have become non existent if it had not been converted into seaweed meal for livestock feed. The market demand was then ranging between 30 and 40 000 tons of fresh kelp. When other plant proteins came on the market, especially soy flour, this activity was ruined. The instability regarding the industrial use of seaweeds is therefore obvious, and as a result is also present in the economic networks derived from it. However, if consumer attraction for nutritional seaweeds gets confirmed, we could be entering a new era characterised by better stability for the network and new technology repercussions especially for the aquaculture. Facing tothe west of the British Channel and the Iroise Sea, which typical hard and rocky coastal sea bottoms produce crabs, lobsters and crayfish, North Brittany has developed a significant pot and net fishing activity. This group of species accounts for, in value, a third of all products disembarked between Saint-Malo and Camaret and half of the national crab production comes from the activity of that fleet. This activity is marked by the general characteristics of coastal fishing and small scale fishing: strong flexibility allowing units to simultaneously or consecutively use several trades (line, long line, dredge,...), but nevertheless faces, structural problems, which up to now, have prevented the optimization of collective interests: unloading point dispersion, difficulties in evaluating production and effort developments, lack of market organisation, low level of professional and inter-professional organisation. To this context, we now need to ad increasing competition with British and Anglo-Normand fleet regarding common stocks exploitation and increasing importation from the United Kingdom and Ireland which most significant impact for the past three years has resulted in steady first sale average price reduction. When adding to this picture specific problems related to crustacean demographic structures studies or simply growth modelisation, we can see the framework in which the program conducted for this resource was developed: fleet typologies test (all trades West British Channel, 1986 file) mapping resources, their quantitative and qualitative characteristics, stock or exploitation units identification, - reconstituting production and effort statistical study charts and improving collecting tools, reconstituting abundance indexes by species and exploitation units developing cooperative work with the British in order to analyse stocks as a whole geographically, acquiring or increasing knowledge on species biology, especially regarding growth by setting up new technology, reproduction, and natural mortality factor pathology (identifying a dinoflagellata causing common crab winter seasonal deaths, since 1985) - studying spider crab net selectivity, studying stocks, through direct evaluation (spider crab batch) or horde analysis - regulation measures proposals