Resource structure of an artisanal gillnet fishery in the coastal waters of Tamsui, Taiwan

Abstract

This study investigated the resource structure of an artisanal gillnet fishery in the coastal waters of Tamsui, Taiwan from June 2015 to May 2016. The catch rate (CR) varied by month. The highest CR (126.4 kg/1000 m^2) was observed in December, and the lowest, approximately 13 kg/1000 m^2, in March. The Shannon diversity index (H') and diversity threshold value (Dv) exhibited similar trends, peaking in May and reaching their lowest points in November. The evenness index remained relatively stable. A total of 17 species commonly appeared in this area. The dominant species, Mugil cephalus, which is affected by climatic factors, was the crucial species influencing the resource structure (i.e., relative importance index) of the artisanal gillnet fishery. The monthly resource structure of the artisanal gillnet fishery was therefore unstable and is believed to be influenced by the marine environment. The association of the resource structure of the artisanal gillnet fishery with environmental changes in the coastal waters of western Taiwan will be further investigated in future.