Using Standardized CPUE to Estimate the Effect of Artificial Reefs on Fish Abundance

Catch per unit effort (CPUE), calculated from data obtained from commercial fisheries, is widely used for resource assessment. However, the untransformed nominal CPUE data are affected by many factors (e.g., natural annual and seasonal fluctuations, differences in fishing areas and fishing gear). Consequently, using the nominal CPUE data does not allow an accurate evaluation of the effect that an artificial reef may have on fish stocks. Standardized CPUE, which is considered as a stock abundance index, is a fundamental component of fishery stock assessment. In this study, we apply the standardized CPUE method for removing the same factors’ impact, except for that of the artificial reef, from the nominal CPUE to estimate the effect of artificial reefs on fish abundance for Japanese butterfish (Hyperoglyphe japonica).