Planning the next fishing trip: where are the gaps in knowledge about freshwater fish assemblages in Argentina?

In this study, we present a new method to compare the distribution of knowledge regarding the biodiversity of a taxa with the distribution of environments inhabited by that taxa, in order to identify the main geographical gaps in biodiversity knowledge. We compared the geographical distribution of studies describing freshwater fish assemblages in Argentina with the distribution of freshwater bodies, delimiting priority areas that require additional sampling effort in order to achieve a more balanced understanding of this taxa’s diversity throughout the country. Our results show a substantial geographical bias in the distribution of knowledge regarding freshwater fish assemblages in Argentina, with most of the studies concentrating on a few areas of the country. Many sectors appear as undersampled, and most of the country has been studied only recently, after many sites have undergone severe impact by anthropic activities. The absence of fish assemblages descriptions previous to habitat changes in these sites considerably limits our capacity to understand changes in biodiversity that anthropic habitat modifications might have generated or even the ones they are generating now. We show the areas of Argentina where freshwater fish diversity needs to be studied most urgently based on the distribution of freshwater habitats.