Developing native fish species for aquaculture: the interacting demands of biodiversity, sustainable aquaculture and livelihoods

Aquaculture continues to be the fastest growing animal production industry and this rate of expansion must continue if aquaculture is to satisfy global demand for fish products in the face of dwindling capture fisheries. The relationship between aquaculture and biodiversity is complex, with examples of positive and negative impacts having been reported. To enable this expansion while avoiding negative impacts from introductions of exotic species, the investigation of indigenous species becomes important and worthwhile.This paper establishes the background to development of new species for culture and describes the example of the Mexican silverside Menidia estor, which has for centuries been the principal species in an artesanal fishery in Lake Patzcuaro, Mexico. The species is geographically isolated and is unique but is now endangered because of a range of factors including overfishing, environmental degradation and introduction of exotic species. Considerable advances have been made recently in developing a closed reproductive cycle, understanding feeding and small-scale on-growing technology for the species. Based on this, a Darwin Initiative programme was developed focused on technology transfer to implement small-scale pilot on-growing thus helping to conserve the species and to improve livelihoods. This has allowed successful pilot scale development of aquaculture for the species while at the same time addressing the objectives of the international Convention on Biodiversity.