Data/hora: 12/06/2024 07:30:29

Provedor de dados: 	5	
País: 	France	
Título: 	Summer mortality of Crassostrea gigas (Thunberg) in relation to environmental rearing conditions	
Autores: 	Soletchnik, Patrick; Lambert, Christian; Costil, Katherine.	
Data: 	2005	
Ano: 	2005	
Palavras-chave: 	Summer mortality; Hydrology; Sediment; Marine ecosystem; Marennes Oleron Bay; Crassostrea gigas.	
Resumo: 	The purpose of this study is to investigate summer mortality of the cupped oyster, Crassostrea gigas, in relation to culture practices in the traditional oyster production region of Marennes-Oleron (France). Four oyster rearing conditions, varying culture location ("on-" or "off-bottom"), and site depth (65% to 80% daily immersion termed "deep" or 45% to 65%, termed "shallow") were studied to compare biologic performance and maturation status of oysters, in relation to sediment and water column parameters. The most severe mortality occurred in June to July in "on-bottom" reared oysters (25%), as compared with 10% mortality in "off-bottom" cultured oysters. Oysters (shell and meat) grew significantly better when reared "off-bottom" than "on-bottom." Reproductive effort was almost double in "off-bottom" reared oysters, compared with those "on-bottom"; thus, reproduction cannot be directly related to mortality in this summer mortality event. Low glycogen content recorded for both "on" and "off-bottom" reared oysters in summer, confirmed the probable lack of food and/or the overstocking in the Marennes-Oleron Bay, but did not discriminated among culture conditions. Whatever the immersion depth ("deep" or "shallow" conditions), "on-bottom" cultured oysters were adversely affected in growth, reproductive effort, and survival suggesting a direct effect of the mud (the so called "mud effect") on the biologic performance of oysters cultured on the bottom. Data from monitoring of sediment redox potential, organic content, and ammonium release did not support hypotheses that these parameters were alone responsible for the observed differences in mortality events.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/2005/publication-3171.pdf	
Editor: 	The National Shellfisheries Association	
Relação: 	http://archimer.ifremer.fr/doc/00000/3171/	
Formato: 	application/pdf	
Fonte: 	Journal of Shellfish Research (0730-8000) (The National Shellfisheries Association), 2005 , Vol. 24 , N. 1 , P. 197-207	
Fonte: 	2005 National Shellfisheries Association