Distribution modeling of dolphinfish (Coryphaena hippurus) in the Pacific Ocean off Peru, Evidence of seasonnal pattern

Abstract

Data from the dolphinfish longline artisanal fishery and oceanographic covariates for 2010 – 2017 period, were used to estimate dolphinfish relative density and characterize its spatial distribution in the Pacific Ocean off Peru from 4°S – 16°S. We identified that high relative densities were located between 9°S and 12°S in the period November – January and approximately at 190 nautical miles (nm) distance from the coast on average. On the other hand, low relative densities occur near and along the coast in the period February – March and at 115 nm distance from the coast on average, which suggested a migratory behavior of this species. Nevertheless, in this study, there is no evidence of a reverse migration to the northwest. According to the environmental variables, dolphinfish prefer to stay in sea surface temperature (SST) ranging from 21° - 24°C, lower chlorophyll-a concentration (CHL) 1 mg/3 , and surface sea height (SSH) ranged from 0.10 to 0.20. The information derived from this study such as maps, spatial indicators, and time series, could improve our knowledge of how the spatial distribution and relative density of dolphinfish is likely to vary with future conditions and give some clues to forecast fishing grounds in short or long term. Finally, these results can provide tools to develop and/or improve management and conservation plans for a sustainable harvest of this species that supports one of the most important artisanal fisheries in Peru. (slides available upon request)