Native or non-native? That is the question: A complementary discussion to Saint-Paul (2017)

Abstract

Saint-Paul (2017) discussed the use of native species in the Brazilian aquaculture, arguing that the selection of species to meet the national demand is concluded. However, many species used in aquaculture are not autochthonous to the basin where they are cultivated, and then should not be considered native. Here we highlight the risks of intra-country introductions in a country with continental dimensions such as Brazil, that shelters a great variety of ecoregions and Ramsar sites. Natural barriers are biologically more relevant than geopolitical divisions, so Brazilian species should be considered as non-native if they are introduced into a basin where they do not occur naturally. Concerning this, we aim to claim the attention to the issue, demonstrating that aquaculture in Brazil still have to be improved, based on sustainable strategies such as: i) to make aquaculture more environmentally-friendly, especially by avoiding leaks and pollution (i.e. biotic and abiotic - prevent escapes and eutrophication) to natural ecosystems; ii) to regionalize production promoting the use of locally native species (native in the region, basin and/or sub-basin) exploring local markets; iii) to avoid hybrids; iv) to improve technology in all phases of management; v) to improve measures, both mitigating and compensatory, or penalties and liabilities in cases of leakage (e.g. polluter pays principle) and vi) a profound change in policies and laws, adopting the Precautionary Principle and considering the effects of aquaculture on biodiversity and ecosystems services,, and in particular, with regard to treaties to which it is a signatory. For example, the 10th Conference of the Parties to the Convention on Biological Diversity (CBD, Nagoya Protocol), where Brazil and 192 other countries have established a Strategic Plan and targets to reduce biodiversity loss on a global scale - the Aichi Biodiversity Targets. Besides that, the use of native species is preferred but those species should be selected taken biological and biogeographical frontiers into consideration that will not impact in the ecosystem. The current situation demands a profound behavioral shift towards novel and better practices, or aquaculture will continue to erode the aquatic biodiversity without a positive growth.