Damage or benefit? How future scenarios of climate change may affect the distribution of small pelagic fishes in the coastal seas of the Americas

Abstract Species occurrence and distribution have already been directly affected by climate change, a scenario that is likely to be accentuated as the temperature rise is expected to exceed 2 °C by 2100. Owing to climate change, organisms are forced to migrate or adapt to new climatic conditions, and if they fail to do so, they are at risk of declining and becoming extinct. However, some species are adapted to overcome and even benefit from these new conditions, increasing their occurrence area or even their abundance. Using Bayesian Species Distribution Models (B-SDMs), we evaluated the current distribution of two halfbeak fishes, Hyporhamphus unifasciatus and Hemiramphus brasiliensis, and the effect of climate changes predicted for 2050 and 2100 on the distribution of these populations in coastal waters of the Americas. We used species occurrence data from bibliographical sources and online databases. One biotic (net primary production - NPP) and four abiotic variables (sea surface temperature - SST), sea surface salinity - SSS), depth, and sea bottom rugosity) were used as potential predictors of species distribution. Results indicated that both species are more likely found in shallower, warmer, and saltier waters. Model prediction suggests that they will probably benefit from climate change, with potential increase in their occurrence area in coastal regions of the Americas, especially due to temperature rise and increased salinity.