@article {4396, title = {Meiofauna distribution in a mangrove forest exposed to shrimp farm effluents (New Caledonia)}, journal = {Marine Environmental Research}, volume = {119}, year = {2016}, pages = {100 - 113}, abstract = {

Abstract Meiofauna abundance, biomass and individual size were studied in mangrove sediments subjected to shrimp farm effluents in New Caledonia. Two strategies were developed: i) meiofauna examination during the active (AP) and the non-active (NAP) periods of the farm in five mangrove stands characteristics of the mangrove zonation along this coastline, ii) meiofauna examination every two months during one year in the stand the closest to the pond (i.e. Avicennia marina). Thirteen taxonomic groups of meiofauna were identified, with nematodes and copepods being the most abundant ones. Meiofauna abundance and biomass increased from the land side to the sea side of the mangrove probably as a result of the increased length of tidal immersion. Abundance of total meiofauna was not significantly different before and after the rearing period. However, the effluent-receiving mangrove presented twice the meiofauna abundance and biomass than the control one. Among rare taxa, mites appeared extremely sensitive to this perturbation.

}, keywords = {New Caledonia}, issn = {0141-1136}, doi = {http://dx.doi.org/10.1016/j.marenvres.2016.05.028}, url = {http://www.sciencedirect.com/science/article/pii/S0141113616300976}, author = {L. Della Patrona and Cyril Marchand and C{\'e}dric Hubas and Nathalie Molnar and J. Deborde and Tarik Meziane} } @article {3559, title = {Concentrations and Fractionation of Carbon, Iron, Sulfur, Nitrogen and Phosphorus in Mangrove Sediments Along an Intertidal Gradient (Semi-Arid Climate, New Caledonia)}, journal = {J. Mar. Sci. Eng.}, year = {2015}, month = {02/2015}, pages = {52-57}, type = {OPEN ACCESS}, abstract = {

In mangrove ecosystems, strong reciprocal interactions exist between plant and substrate. Under semi-arid climate, Rhizophora spp. are usually predominant, colonizing the seashore, and Avicennia marina develops at the edge of salt-flats, which is the highest zone in the intertidal range. Along this zonation, distribution and speciation of C, Fe, S, N, and P in sediments and pore-waters were investigated. From the land-side to the sea-side of the mangrove, sediments were characterized by I/ increase in: (i) water content; (ii) TOC; (iii) mangrove-derived OM; II/ and decrease in: (i) salinity; (ii) redox; (iii) pH; (iv) solid Fe and solid P. Beneath Avicennia and Rhizophora, TS accumulated at depth, probably as a result of reduction of iron oxides and sulfate. The loss of total Fe observed towards the sea-side may be related to sulfur oxidation and to more intense tidal flushing of dissolved components. Except the organic forms, dissolved N and P concentrations were very low beneath Avicennia and Rhizophora stands, probably as a result of their uptake by the root systems. However, in the unvegetated salt-flat, NH4+ can accumulate in organic rich and anoxic layers. This study shows: (i) the evolution of mangrove sediment biogeochemistry along the intertidal zone as a result of the different duration of tidal inundation and organic enrichment; and (ii) the strong links between the distribution and speciation of the different elements.

}, keywords = {biogeochemistry, Mangrove, New Caledonia, zonation}, issn = {2077-1312}, author = {Jonhatan Deborde and Cyril Marchand and Nathalie Molnar and Luc Della-Patrona and Tarik Meziane} } @article {3663, title = {Foraminiferal assemblages as bioindicators to assess potential pollution in mangroves used as a natural biofilter for shrimp farm effluents (New Caledonia)}, journal = {Marine Pollution Bulletin}, volume = {93}, year = {2015}, month = {15 April 2015}, pages = {103-120}, type = {Research}, abstract = {

In New Caledonia, semi-intensive shrimp farms release untreated effluents into the mangrove. Foraminiferal assemblages were analyzed for assessing the impact of effluent release on the benthic compartment. Comparison was made between samples collected (1) in an effluent receiving mangrove before and after the rearing cycle, and (2) for one-year monitoring an effluent receiving and a control mangrove. The distribution of foraminiferal assemblages was primarily driven by the gradient between\ Rhizophora\ stands and salt-flats, related to salinity and tidal elevation, and by seasonal cycles. The potential impact of effluent release was due to the combined effects of normal-saline effluents on surface salinity, and of nutrient input and microbial stimulation on food availability. Foraminiferal assemblages did not indicate a substantial impact of farm effluents and suggest that semi-intensive shrimp farming using mangrove for effluent discharge may appear as a sustainable solution in New Caledonia, when considering only the impact on the mangrove itself.

}, keywords = {Effluents, fatty acids, Foraminifera, Mangrove, Shrimp farming, SW Pacific}, doi = {10.1016/j.marpolbul.2015.02.009}, author = {Debenay, J-P and Cyril Marchand and Nathalie Molnar and Ad{\'e}laide Aschenbroich and Tarik Meziane} } @article {3522, title = {Spatio-temporal variations in the composition of organic matter in surface sediments of a mangrove receiving shrimp farm effluents (New Caledonia)}, journal = {Science of The Total Environment}, volume = {512{\textendash}513}, year = {2015}, pages = {296 - 307}, abstract = {

In order to investigate spatio-temporal variations in the composition and origin of the benthic organic matter (OM) at the sediment surface in mangrove receiving shrimp farm effluents, fatty acid (FA) biomarkers, natural stable isotopes (δ13C and δ15N), C:N ratios and chlorophyll-a (chl-a) concentrations were determined during the active and the non-active period of the farm. Fatty acid compositions in surface sediments within the mangrove forest indicated that organic matter inputs varied along the year as a result of farm activity. Effluents were the source of fresh particulate organic matter for the mangrove, as evidenced by the unsaturated fatty acid (UFA) distribution. The anthropogenic \{MUFA\} 18:1ω9 was not only accumulated at the sediment surface in some parts of the mangrove, but was also exported to the seafront. Direct release of bacteria and enhanced in situ production of fungi, as revealed by specific FAs, stimulated mangrove litter decomposition under effluent runoff condition. Also, microalgae released from ponds contributed to maintain high benthic chl-a concentrations in mangrove sediments in winter and to a shift in microphytobenthic community assemblage. Primary production was high whether the farm released effluent or not which questioned the temporary effect of shrimp farm effluent on benthic microalgae dynamic. This study outlined that mangrove benthic organic matter was qualitatively and quantitatively affected by shrimp farm effluent release and that responses to environmental condition changes likely depended on mangrove stand characteristics.

}, keywords = {Chlorophyll-a, fatty acids, Mangrove, Organic matter, Shrimp farming, Stable isotopes}, issn = {0048-9697}, doi = {http://dx.doi.org/10.1016/j.scitotenv.2014.12.082}, url = {http://www.sciencedirect.com/science/article/pii/S0048969714017938}, author = {Ad{\'e}laide Aschenbroich and Cyril Marchand and Nathalie Molnar and Jonhatan Deborde and C{\'e}dric Hubas and Herv{\'e} Rybarczyk and Tarik Meziane} }