Annual Cycles and Budget of Nutrients in Berre Lagoon (Mediterranean Sea, France)

Abstract

key words: nutrients, hydrology, nutrient budget. Rerre lagoon Abstract The annual cycles of nutrients in t,he Etang de Berre were studied in 1985. From measnrement>s twice a month at the input points, daily data for the freshwater flow and from daily measurements a t the ontput point, an estimation is proposed for a nutrient budget. Seasonal variability is iniportant, and a biological contml of nutrient av;dabilit,y (lordly remineralized products) results in it Iiydrologically controlled system (nutrients carried by continental waters) which produces the very high microalgal biomass observed in the lagoon. The seasona.1 hit locline brings the euphotic layer very close to t,he reminerizlizatiol~ site: nutrients are then constantly available to the phytoplankton.

Phytoplankton biomass and species composition in a Mediterranean coastal lagoon

“…Maximal chlorophyll values which were measured in the Fusaro lagoon are in the upper range reported to date for other lagoons and, for the Mediterranean Sea, are only comparable to values recorded in proximity to the sea-mouth of the Berre Lagoon, France in 1985 (Arfi, 1989), in the Sacca del Canarin, Italy (Solazzi etal., Calycomonas cfr. wulffii and in the Mauguio lagoon, France (Vaulot & Frisoni, 1986).…”

Man-induced hydrological changes, metazooplankton communities and invasive species in the Berre Lagoon (Mediterranean Sea, France)

“…At the time, these inputs represented 3.3 Â 10 9 m 3 y À1 of freshwater (3.7 times the lagoon volume) and 520,000 t y À1 of silt. Due to no or very few controls for a long time, the release of freshwater and silt in the lagoon led to modifications of the morphology (i.e., topography of the bottom, quality and size of sediments), the hydrodynamic and the ecological functioning of the entire lagoon, causing intense eutrophication (Minas, 1974(Minas, , 1976bArfi, 1989Arfi, , 1991Caddy, 2000;Gouze et al, 2008), leading to significant anoxia events (Minas, 1974(Minas, , 1976aNerini et al, 2000).…”

Levels Of Linear Alkylbenzenesulfonates (LAS) In Sediments Of The Berre Lagoon (FRANCE)

“…The most important natural inflow of fresh water is provided by the Arc River, which established a large delta in the Berre Lagoon. Furthermore, a large freshwater volume of the Durance river is canalised and rejected in the lagoon, by the intermediary of the hydroelectric plant of St Chamas (around 3.5 Â 10 9 m 3 =year) and by the Craponne canal (3.0 m 3 =s) [26]. Consequently, the salinity of the lagoon that was initially the same as that of the Mediterranean Sea has fallen to a level of 15-20 g=L.…”

“…The St Chamas canal represents a fresh water input, which varies seasonally according to energy demand. Maximum inflows occur from November to June and minimum from July to October [26]. Because of these hydrological features, important salinity variations are observed in the Berre lagoon, which are particularly prejudicial to local marine fauna [33,34].…”