Élevage du concombre de mer dans un système d'Intégration Multi-Trophique (polyculture).

Abstract

Integrated multi-trophic aquaculture (IMTA) represents an innovative and flexible approach for developing sustainable aquatic production systems that can enhance the environmental quality of marine ecosystems. The objective of this work is to provide initial insights into the feasibility of polyculture between sea urchins and sea cucumbers. The study focused on the survival capacity of these marine invertebrates based on diets consisting mainly of algal debris of fishmeal, two available, economical, and sustainable resources. A total of 42 holothurians and 24 sea urchins were collected from Stidia-West (Mostaganem, Algeria) and monitored daily for water physiochemical parameters. Two experimental tank trials were carried out and compared: (1) a monoculture of holothurians fed with fishmeal (2% of total weight, incorporated into the sediment), and (2) a polyculture of holothurians-sea urchins fed with algal debris in cages. Biological performance was assessed through mortality rate (TM), survival rate (TS), and specific growth rate (SGR). The results show that the fishmeal diet led to total mortality of holothurians (TM = 100%, TS = 0%). In contrast, the polyculture with algal debris yielded better outcomes (TM = 11.4%, TS = 88.6%, holothurian SGR = -0.114% d-1), despite a slight weight loss in sea urchins. Water physicochemical parameters remained within aquaculture standards. These observations suggest that holothurian-sea urchin integration, combined with algal biomass, promising pathway for the sustainable development of holothuriculture in Algeria.