The role of Holothuria tubulosa in organic matter recycling of Posidonia oceanica detritus was estimated in alaboratory feeding experiment. The individual mean ingestion rate of seagrass detritus by holothurians wasevaluated and carbon and nitrogen stable isotopes, carbon and nitrogen content and C:N ratio analyzed inH. tubulosa, P. oceanica detritus and surface sediment. Results showed that H. tubulosa is capable of ingestingfrom 30% to 100% of the detritus produced by P. oceanica meadows, depending on the holothurian density. Stableisotope analysis provided evidence for the assimilation of seagrass detritus by H. tubulosa as their signatureswerecompatible with 1 trophic level-step, and for the accumulation of organic material of seagrass origin intosediments, being their δ13Ccloser to that of P. oceanica only in aquaria with holothurians. As a result, holothuriansaffected the transfer of seagrass-derived organic matter to surface sediments, enhancing the sediment uptakeof organic carbon and total nitrogen by up to 30× and 3×, respectively. Quantitative information on the role ofH. tubulosa in seagrass meadows highlights the importance of this species in accelerating the degradation ofseagrass detritus, affecting its recycling and availability for seagrass benthic communities.
|Numero di pagine||7|
|Rivista||Journal of Experimental Marine Biology and Ecology|
|Stato di pubblicazione||Published - 2014|
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