Relationship between change of bigeye tuna catches by Chinese tuna purse seine fleets and FAD closure

We analyzed the relationship between the change of bigeye tuna (Thunnus obesus) catches by Chinese tuna purse seine fleets and fish aggregation devices (FADs) closure during the Conservation and Management Measures in the Western and Central Pacific Ocean from 2012 to 2015.The Chinese tuna purse seine fishery data were collected to compare the difference between fishing efforts (sets) of associated school and catches of small and large bigeye tuna.The results show that:1) The proportion of associated school sets among total sets had declined since 2013, which was under 50%.2) The result of K-S testing shows that the average associated school sets were different before and after FAD closure significantly.3) The average catch of total bigeye tuna from 2013 to 2015 was lower than that in 2012 significantly.4) The catch of bigeye tuna had increased since 2012 in the first month at the end of the FAD closure rapidly.5) The fishing effort and catches of both small bigeye tuna and all bigeye tuna had significant positive correlation in 2013 and 2014 (P < 0.05).The results show that the bycatch of juvenile bigeye tuna by Chinese tuna purse seine fleets had decreased since 2012, which might result from the FAD closure measure adopted in 2013 which had extended additional one-month FAD closure.