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

• Published in: Marine pollution bulletin Vol. 64; no. 9; pp. 1921 - 1932
• Main Authors: Delpy, Floriane, Pagano, Marc, Blanchot, Jean, Carlotti, François, Thibault-Botha, Delphine
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-09-2012; Elsevier
• Subjects: Acartia clausi; Acartia tonsa; Animals; Anthropogenic pressure; Aurelia aurita; Berre Lagoon; Biodiversity; Biodiversity and Ecology; Brachionus plicatilis; Brackish water; Centropages typicus; Chlorophyll - analysis; Communities; Environmental Monitoring; Environmental Sciences; France; freshwater; Humans; Hydrology; Introduced Species - statistics & numerical data; invasive species; Lagoons; Litigation; Marine; Mediterranean Sea; Mnemiopsis leidyi; Paracalanus parvus; Pollution abatement; power plants; Salinity; Scyphozoa; Seawater - chemistry; water pollution; Water Pollution - analysis; Water Pollution - statistics & numerical data; Zooplankton; Zooplankton - classification; Zooplankton - growth & development; Zooplankton community; France; Mediterranean Sea; MED, France, Languedoc-Roussillon, Berre Lagoon; MED, France; Berre Lagoon; Hydrology; Zooplankton community; Mnemiopsis leidyi; Brackish water; Anthropogenic pressure
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2012.06.020

► Hydrological conditions in Berre drastically changed after rehabilitation efforts. ► Zooplankton community became more diverse with success of marine species. ► The structuring role of salinity decreased. ► Several allochtonous species were introduced. ► Proliferation of gelatinous zooplankton (M. leidyi) was observed.
The Berre Lagoon has been under strong anthropogenic pressure since the early 1950s. The opening of the hydroelectric EDF power plant in 1966 led to large salinity drops. The zooplankton community was mainly composed of two common brackish species: Acartia tonsa and Brachionus plicatilis. Since 2006, European litigation has strongly constrained the input of freshwater, maintaining the salinity above 15. A study was performed between 2008 and 2010 to evaluate how these modifications have impacted the zooplankton community. Our results show that the community is more diverse and contains several coastal marine species (i.e., Centropages typicus, Paracalanus parvus and Acartia clausi). A. tonsa is still present but is less abundant, whereas B. plicatilis has completely disappeared. Strong predatory marine species, such as chaetognaths, the large conspicuous autochtonous jellyfish Aurelia aurita and the invasive ctenophore Mnemiopsis leidyi, are now very common as either seasonal or permanent features of the lagoon.