Benthic metabolism in shallow coastal ecosystems of the Banc d'Arguin, Mauritania
|Author(s)||Clavier Jacques1, Chauvaud Laurent1, Amice Erwan1, Lazure Pascal2, Van Der Geest Matthijs3, Labrosse Pierre4, Diagne Ahmed4, Carlier Antoine5, Chauvaud Sylvain6|
|Affiliation(s)||1 : Inst Univ Europeen de la Mer, CNRS, UMR 6539, IUEM,Lab Sci Environm Marin, F-29280 Plouzane, France.
2 : IFREMER, Lab Phys Hydrodynam Sedimentaire, Ctr Bretagne, F-29280 Plouzane, France.
3 : NIOZ, Royal Netherlands Inst Sea Res, Dept Marine Ecol, NL-1790 AB Den Burg, Texel, Netherlands.
4 : IMROP, Nouadhibou, Mauritania.
5 : IFREMER, Ctr Bretagne, Lab Ecol Benthique, F-29280 Plouzane, France.
6 : TBM, F-56400 Auray, France.
|Source||Marine Ecology Progress Series (0171-8630) (Inter-research), 2014 , Vol. 501 , P. 11-23|
|WOS© Times Cited||10|
|Keyword(s)||Seagrass, Carbon metabolism, Intertidal, Subtidal, Respiration, Primary, production, Western Africa|
|Abstract||Benthic primary production and respiration were investigated at 4 sites representative of the major coastal communities bordering the Sahara Desert in the Banc d'Arguin, Mauritania, Western Africa. These sites correspond to intertidal Zostera noltii beds (270 km(2)), intertidal bare sediments (88 km(2)), subtidal Cymodocea nodosa beds (374 km(2)), and subtidal bare sediments (311 km(2)). At each site, production-irradiance relationships were established in situ in November 2008 and January 2010, and used to calculate daily carbon fluxes for these communities. In intertidal areas, compared to emersion, the gross maximal photosynthetic rates for Z. noltii bed and bare sediment communities were on average 8-and 7-fold higher during immersion, respectively; community respiration rates were 3-and 18-fold higher during immersion, respectively. The Z. noltii bed was autotrophic during the 2 study periods, with a mean (+/- 95% probability limit) daily net community production of 71.3 +/- 58.6 mmol C m(-2) d(-1). Conversely, net community production was always negative in intertidal regions and subtidal bare sediments (average -7.3 +/- 46.7 mmol C m(-2) d(-1) and -47.0 +/- 38.9 mmol C m(-2) d(-1), respectively); the C. nodosa bed was negative in November (-96.2 +/- 85.1 mmol C m(-2) d(-1)) and positive in January (33.4 +/- 82.6 mmol C m(-2) d(-1)). Community respiration was highest in subtidal communities, indicating active mineralization of organic matter and demonstrating that Z. noltii beds are likely to increase the bio logical richness of the Banc d'Arguin by exporting energy. Our results confirm the ecological importance of seagrass beds in the net coastal carbon fluxes and justify their protection.|