Determination of propitious areas for the responsible development of Bijupirá production in networked tanks in the southern region of the state of Rio de Janeiro
Projections indicate that global demand for fish will reach up to 187 million tonnes, with aquaculture production equaling global fish production. The use of coastal ecosystems and the open sea will increase substantially, placing further environmental pressures on nature, products and services. Interventions with short-term objectives and geopolitical limits, without paying enough attention to other key criteria for the success of the activity usually result in limited development and sustainability. On the south coast of Rio de Janeiro, the cultivation of bijupirá has been emerging as an activity with great potential. Despite the good results obtained so far, there are still several fundamental issues for the sustainable development of the activity, including management techniques,the lack of regulation and opposition to the activity centered on the mistaken perception of its polluting potential, these being just some of the challenges that need to be overcome. This study sought to replace the unsustainable management practices currently used, generating bases of understanding for producers; evaluate the possible impacts of the cultivation of bijupirá in net tanks near the coast; formulate a predictive model of deposition and dispersion and present a methodology that to define areas for marine aquaculture and consequently select the most suitable areas thus contributing to the responsible development of marine fish farming on the south coast of Rio de Janeiro.There were no negative effects on productive performance and an improvement in environmental efficiency was registered in the substitution of the use of regularly used humid diets, this methodology being used capable of demonstrating to the producers the benefits of substituting humid diets. In relation to the environmental impacts of crops, the effects of nutrient discharge on water quality and its secondary complications are minimal and have remained within the normal parameters of the environment and legal limits in force in Brazil. The impacts on the sediment were also minimal, there were no accumulations of TOC and no changes in the communities. The sedimentation was more concentrated below the tanks and the maximum deposition rates of MO and TOC verified in situ and predicted in the model, were characterized as low impact.The total of areas identified as adequate and very adequate is sufficient to guarantee the implantation and expansion of the cultivation of marine fish on the southern coast of Rio de Janeiro. For a better application of sustainable guidelines, it is suggested the adoption of limited production areas, based especially on the productive support capacity.