The influence of environmental variation on trophic ecology of Dosidicus gigas along Peruvian coast

Abstract Environmental variation changes abundance and diversity in pelagic communities and consequently can influence the diet of marine predators by diversity of available prey. The feeding habits of the jumbo squid Dosidicus gigas from the Peruvian coast were studied by analyzing the gastric content of 1020 stomachs in the period 2015–2019. The diet was analyzed in terms of frequency of occurrence (% FO), number (% N) and weight of prey (% P). In addition, to evaluate the trophic spectrum several diversity indices were calculated and compared with body size of squids, sea surface temperature (SST), southern oscillation index (SOI) and geographic location. Fish represented 96% of full stomachs, and Vinciguerria lucetia was the most frequent and abundant species, followed by myctophid fishes. The principal variables analyzed influencing the diet of D. gigas were SST and SOI, followed by latitude. The trophic level was estimated between 3.6 and 4.4 being the lowest value during 2016. The occurrence of coastal El Niño event during 2016 influence the available prey and consequently the prey composition and diversity of jumbo squids and in consequence the trophic level at population scale.