Skip to main content

Assessing the production and the impact of cultivated oysters in the Thau lagoon (Mediterranee, France) with a population dynamics model

Buy Article:

$50.00 plus tax (Refund Policy)

Abstract:

The Thau lagoon (France) has been studied for many years because of its ecological interest related to economic activities: shellfish cultivation, tourism, and industry. The standing stock of cultivated filter feeders is around 20 000 t and consists of two main species, the Japanese oyster Crassostrea gigas and the Mediterranean mussel Mytilus galloprovincialis. To predict changes in the standing stock and the annual production, a mathematical model of the population dynamics was defined. It was based on the continuous equation of the density as a function of the mortality rate, the individual growth rate, and the interindividual variability. The daily growth rate was derived from field surveys and depended on the phytoplankton concentration and individual weight. The model also took into account the rearing strategy of the producers defined by the timetable of seeding and harvesting, obtained by an inquiry among the producers and used to simulate real cases of standing stock changes. The model was also used to assess the potential impact on the environment through the computation of the food consumption, which was compared with the residence time and the primary production.

Ses nombreuses activités économiques (élevage conchylicole, tourisme et industrie) font de l'étang de Thau (France), un site intéressant d'un point de vue écologique. C'est pourquoi, des études y sont menées depuis plusieurs années. La biomasse de mollusques en élevage dans l'étang est de l'ordre de 20 000 tonnes. Deux espèces y sont élevées : l'huître creuse, Crassostrea gigas, et la moule de Méditerranée, Mytilus galloprovincialis. Un modèle mathématique de dynamique de population a été élaboré permettant de prédire les variations temporelles de la biomasse ainsi que la production annuelle du bassin. Ce modèle est basé sur une équation continue de la densité, fonction de la mortalité, de la croissance individuelle et de la variabilité inter individuelle. Le taux de croissance dépend de la concentration en phytoplancton et du poids total individuel. Le modèle intègre également les stratégies d'élevage, i.e., l'ensemencement et la récolte, définies à partir d'enquêtes réalisées auprès des producteurs. Il permet ainsi de simuler des cas réels de variations de biomasse. Dans un second temps, le calcul de la consommation phytoplanctonique par les bivalves permet d'estimer leur impact sur l'écosystème. La consommation est comparée au temps de résidence et à la production primaire dans l'étang.

Document Type: Research Article

Publication date: May 1, 2001

More about this publication?
  • Published continuously since 1901 (under various titles), this monthly journal is the primary publishing vehicle for the multidisciplinary field of aquatic sciences. It publishes perspectives (syntheses, critiques, and re-evaluations), discussions (comments and replies), articles, and rapid communications, relating to current research on cells, organisms, populations, ecosystems, or processes that affect aquatic systems. The journal seeks to amplify, modify, question, or redirect accumulated knowledge in the field of fisheries and aquatic science. Occasional supplements are dedicated to single topics or to proceedings of international symposia.
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Terms & Conditions
  • Sample Issue
  • Reprints & Permissions
  • ingentaconnect is not responsible for the content or availability of external websites
nrc/cjfas/2001/00000058/00000005/art00018
dcterms_title,dcterms_description,pub_keyword
6
5
20
40
5

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more