CPUE standardization and spatio-temporal distribution modelling of dorado (Coryphaena hippurus) in the Pacific Ocean off Peru

Abstract

Dolphinfish, mahi mahi or dorado, is an epipelagic higly migratory species, mainly oceanic, distributed worldwide in tropical and subtropical waters. In Peru, the fishery of perico is carried out by the longline artisanal fleet and currently their landings represents more than 50% (~ 50 000 tons) of the total landing of perico around the world. The aim of this study are modelling abundance/availability trends and the spatio-temporal distribution of perico in the Pacific Ocean off Peru during the 2009 – 2017 period as a function of spatial (longitud, latitude), temporal (year, month) and environmental variables (sea surface temperatura, salinity and chorophyll). For model building we considered the spatial/temporal autocorrelation and used two approaches, the delta Generalized Additive Models (delta - GAM) and the spatial-temporal zero inflated Bayeasian model (ZIB). A detailed discussion is made using the main variables that trigger spatial and temporal changes in distribution and abundance/availability trend. Spatio-temporal analysis gives us clues about habitat preferences of perico (hotspots) in the transitional areas of Peru (coastal and oceanic), likewise abundance/availability trend would help to develop conservation management.