ISSF Bycatch Reduction Research Cruise on the F/V Mar de Sergio in 2016

A research cruise in support of the International Seafood Sustainability Foundation (ISSF) bycatch reduction project was conducted on the tuna purse seine vessel MAR DE SERGIO, during March-April 2016 in the eastern tropical Atlantic Ocean. During a 4-week period a group of three scientists joined the fishing trip with the following objectives: (1) Improving pre-set estimation of species composition, sizes, and quantities of tunas associated with FADs using acoustics: Attaching fishers´ echo-sounder buoys from four different brands to the FADs to compare signals; (2) Use of three scientific echo-sounders with frequencies of 38, 120 and 200 kHz and an EK80 wideband echo-sounder for the frequency band from 85 kHz to 170 kHz onboard a work boat, followed by intensive spill sampling to compare acoustic data and species composition; (3) Study of fish behavior inside the net; (4) shark fish and release from the net; (5) Making other observations that could lead to further tests of mitigation techniques. Preliminary results of these studies are presented.