Research Article

Assimilation of shrimp farm sediment by Holothuria scabra: a coupled fatty acid and stable isotope approach

¹ Laboratoire des Sciences de l'Environnement Marin, UMR 6539 UBO/CNRS/IRD/IFREMER, Rue Dumont d'Urville, 29280 Plouzané, France
² Université de la Nouvelle-Calédonie, UMR Entropie and LabEx Corail, BP R4, 98851 Nouméa Cedex, New Caledonia
³ Institut Français de Recherche pour l'Exploitation de la Mer. Unité Lagons, Ecosystèmes et Aquaculture Durable en Nouvelle Calédonie, BP 2059, 98846 Nouméa Cedex, New Caledonia
⁴ Agence de Développement Economique de la Nouvelle-Calédonie − ZoNéCo, BP 2384, 98846 Nouméa Cedex, New Caledonia

^* Corresponding author: Gauthier.Schaal@univ-brest.fr

Handling Editor: Verena Trenkel

Received: 22 July 2019
Accepted: 16 March 2020

Abstract

Deposit-feeding sea cucumbers are efficient nutrient recyclers and have the potential to contribute to the limitation of organic matter load in polyculture or integrated aquaculture systems. Assessing how they assimilate organic matter originating from other farmed species is therefore important for the development of such multi-species farming systems. Here, a coupled stable isotope − fatty acid approach was used to characterize the assimilation of organic matter from shrimp (Penaeus stylirostris) farming by Holothuria scabra in an experimental culture system. H. scabra were reared in mesocosms on shrimp farming-originating sediment with and without additional food sources (maize and fish meals). Although fatty acid results did indicate that shrimp-farming sediment was assimilated by holothurids, we found no evidence of maize waste and fish meal contribution to H. scabra organic carbon (no effect on δ¹³C, no accumulation of meal-specific fatty acids). However, a strong effect of fish meal on H. scabra δ¹⁵N was observed, suggesting that this additional food source could represent an alternative source of nitrogen for holothurids. Finally, this study supports the culture of H. scabra as a perspective to reduce sedimentary organic matter excess associated with shrimp farms, and suggest that the addition of selected food sources might contribute to increasing the content in some nitrogen organic compounds in holothurid tissues.