Spatial and Temporal Distribution of a Multiple Gear Fishing Fleet Exploiting the Caribbean Sea and North Brazil Shelf Large Marine Ecosystems

Abstract

An industrial multigear fishing fleet from Venezuela emerged in 2009 as a governmental strategy to reduce the impact of industrial trawling on the Venezuelan coast of the North Brazil Shelf Large Marine Ecosystem. The current study aimed to examine the spatial–temporal distribution of fishing effort and the catch levels obtained by the Venezuelan industrial multigear fishing fleet during the period 2015–2018. Fishing gear types employed by this fleet in order of preference were as follows: bottom longline (target sea catfishes [family Ariidae]), trap (target snappers [family Lutjanidae]), pelagic longline (target tunas [family Scombridae]), hand line (target mackerels [family Scombridae]), and shark longline (target sea catfishes and sharks [families Carcharhinidae, Squalidae, Sphyrnidae, Ginglymostomatidae, Alopiidae, and Triakidae]). The kernel intensity estimator determined that the main fishing area was the North Brazil Shelf (comprising 95% of the total fishing sets). Fishing effort (fishing sets per trip) distribution may be associated with oceanic fronts present in the region. A change in the dynamics of the fleet were recorded, with an increase in the use of bottom longlines, along with a decrease in the use of traps, possibly due to overfishing of resources caught by traps. The analyses of covariance showed a linear and positive relationship between the catch and fishing effort but with significant changes over the study period for traps and bottom longlines, since in the years where the fishing effort of traps was lower there were greater catches by unit of effort, and vice versa for bottom longlines, where lower catches by unit effort were obtained in years with greater effort.