Aquaculture and conservation

Despite the growing importance of aquaculture over recent years, and its key role as an alternative to sea overexploitation, there are still a considerable number of challenges that must be faced by the marine aquaculture sectors, especially those regarding conservation approaches. In spite of the aquaculture impacts, such as organic and nutrient enrichment in the water column and sediments, several strategies to reduce negative impacts have emerged, such as integrated multitrophic aquaculture (IMTA), recirculating aquaculture systems (RAS), or the use of new resources (e.g., amphipod crustaceans) to minimize the impact of eutrophication associated with aquaculture facilities. In order to ensure the sustainable development of fish aquaculture, an improvement of the existing management strategies is necessary as a starting point, preventing and reducing the potential environmental impacts of escapees on coastal ecosystems, as well as their indirect socioeconomic consequences. This chapter also addresses two aspects of concern related to aquaculture expansion: the use of alien and locally absent species in aquaculture and the application of genetic improvement technologies. The impact of farmed fish viral infections on the environment and biodiversity has been scarcely studied, and this chapter provides an update on the present knowledge about viral pathogens. The relevance of ornamental species aquaculture for marine conservation, including social implications and psychological perspective, together with an adequate trade in species is mandatory for conservation aquaculture. Aquaculture opportunities to help protect endangered aquatic species, both by reducing stress on wild populations and by enhancing these populations, are also discussed in this chapter.