Data/hora: 08/06/2024 10:26:03

Provedor de dados: | 5
País: | France
Título: | Incidences des épisodes d'efflorescences de micro algues toxiques sur les écosystèmes et sur les pêcheries de coquillages en baie de Douarnenez
Autores: | Thebaud, Olivier; Veron, Gerard; Fifas, Spyros.
Data: | 2005-09
Ano: | 2005
Palavras-chave: | Temporary fishing ban; Mortality; Economic impact; Fishery; Wedge clam; Donax trunculus; Fermeture temporaire; Mortalité; Impact; Pêcherie; Telline; Donax trunculus.
Resumo: | The commercial fishery for wedge clam, or telline (Donax trunculus) in the bay of Douarnenez in France started in the early 1980ies. During twenty years, the activity has developed, from an opportunistic fishery, into a regular fishing enterprise for 36 fishermen, who derive from it most, if not all, of their revenue. The fishery is nowadays strictly regulated. It is subject to natural variations in the productivity of clam stocks, in relation with meteorological conditions which can strongly affect the stocks.  The bay of Douarnenez has been experiencing regular blooms of harmful algae, both of species leading to shellfish poisoning for human consumption, such as Dinophysis (Diarrhoeic Shellfish Poisoning) and Pseudo-nitzschia (Amnesic Shellfish Poisoning), and of species leading to mortalities of marine animals, such as Karenia mikimotoi. It has been suggested that the occurrence of these blooms can be related to hydrological phenomena, leading to limited exchanges between the bay's waters and the open sea, and to thermal stratification of the water column in summer.  The blooms can lead to slowed growth, as well as increased mortality of clams. Toxins accumulated in the clams also create risks for human consumption, which regularly lead to temporary fishing bans in the bay, in application of national and European health safety regulations.  The aim of the study is to analyse the consequences of these harmful algal blooms on the wedge clam fishery. The dynamics of the blooms having an impact on the fishery are described. The potential impacts of these blooms on clam biology, as well as their consequences on the economic status of fishermen, are analysed. In particular, the economic impacts of temporary fishing bans are discussed, taking into account their potential consequences on markets, and the adaptation strategies of fishermen  The analysis allows identification of further research needs to better evaluate the impacts of harmful algal blooms on the biology and harvesting of clams. Current hypothesis on the determinants of these environmental perturbations, in particular the amplifying role of nutrients of human origin, are also discussed.
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/2005/rapport-1262.pdf
Relação: | http://archimer.ifremer.fr/doc/00000/1262/
Formato: | application/pdf