Calculating of the potential biological removal of cetacean and its implications for management

Accurate predictions of the population of cetacean and anthropogenic disturbances are essential to their conversation, but are limited by the characteristics of the long-lived and low reproductive rates of cetaceans. Potential Biological Removal (PBR) is a mortality limit to maintain population sustainability, and is used to compute conservation reference points for human-caused mortality of marine mammals. This study used simulation methods to identify acceptable levels of human-caused mortality for cetaceans. PBR is calculated as a product of the minimum population estimate (N_MIN), one-half of the maximum net productivity rate (R_MAX), and the recovery factor (F_R). Setting of the three-parameter values will lead to deviations or errors in the estimation of the mortality limit. The PBR was evaluated the basis of the assumption that at least 95% of simulated populations met the proposed management objectives (populations beginning at 30% of the transport capacity (K) recovered to at least MNPL after 80 years). In a variety of scenarios, the PBR that used approximately the 5th percentile of the abundance estimate for N_MIN and a value of 0.5 for F_R met the criteria in bias trials. According to different management objectives, develop alternative parameters of PBR that determine marine mammal conservation reference points for human-caused mortality. This approach may be useful in supporting the establishment of new bycatch management programs.