Mariculture Waste Management

Aquaculture has developed rapidly over the past decades and this trend will probably continue as capture fisheries are in global decline. However, aquaculture is now at a crossroad and there are many critical aspects of its sustainability that need to be addressed like the introduction of organic and inorganic waste into the environment increasing the risk of eutrophication and pollution; introduction of diseases and escapees in the ecosystem affecting biodiversity; and increased risk of overfishing by the increased demand for fishmeal and oils. Therefore, it is important to develop new approaches to achieve an environmentally balanced food supply. In this context, ecological engineering is an emerging field, which uses ecological processes within natural or constructed systems to achieve environmental goals. The most basic ecological engineering approaches are based on the capabilities of unmanipulated organisms to respond by enhancing the assimilation of the wastes produced by aquaculture practices. On the other hand, emerging technologies allow balancing the relative abundance of organisms with different ecosystem functions to avoid disruption by the introduction of massive fed aquaculture species into coastal areas. We emphasize the importance of integrated multitrophic aquaculture as a possible solution to not only treat organic particulate and inorganic dissolved nutrients but also to produce other valuable crops, which, when harvested, participate in removing the converted nutrients from the coastal seas. As environmental costs (externalities) are not presently internalized by business companies, there are no major economic drivers promoting the introduction of ecological engineering tools that would help to control, reduce, and minimize the environmental effects of aquaculture. Regulatory and financial incentives are, therefore, required to recognize the benefits of ecological engineering approaches. To achieve these goals, public acceptance through education and government actions for developing appropriate regulations taking into consideration the services provided by extractive species are needed.