Caswell H, Fujiwara M, Brault S
Biology Department MS 34, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
Proc Natl Acad Sci U S A. 1999 Mar 16;96(6):3308-13. doi: 10.1073/pnas.96.6.3308.
The North Atlantic northern right whale (Eubalaena glacialis) is considered the most endangered large whale species. Its population has recovered only slowly since the cessation of commercial whaling and numbers about 300 individuals. We applied mark-recapture statistics to a catalog of photographically identified individuals to obtain the first statistically rigorous estimates of survival probability for this population. Crude survival decreased from about 0.99 per year in 1980 to about 0.94 in 1994. We combined this survival trend with a reported decrease in reproductive rate into a branching process model to compute population growth rate and extinction probability. Population growth rate declined from about 1. 053 in 1980 to about 0.976 in 1994. Under current conditions the population is doomed to extinction; an upper bound on the expected time to extinction is 191 years. The most effective way to improve the prospects of the population is to reduce mortality. The right whale is at risk from entanglement in fishing gear and from collisions with ships. Reducing this human-caused mortality is essential to the viability of this population.
北大西洋露脊鲸（Eubalaena glacialis）被认为是最濒危的大型鲸类物种。自商业捕鲸停止以来，其种群数量恢复缓慢，目前约有300头。我们将标记重捕统计方法应用于一个通过照片识别个体的目录，以获得该种群生存概率的首个严格统计估计值。粗略的生存率从1980年的每年约0.99降至1994年的约0.94。我们将这种生存趋势与报告的繁殖率下降结合到一个分支过程模型中，以计算种群增长率和灭绝概率。种群增长率从1980年的约1.053降至1994年的约0.976。在当前条件下，该种群注定会灭绝；预计灭绝时间的上限为191年。改善该种群前景的最有效方法是降低死亡率。露脊鲸面临渔具缠绕和与船只碰撞的风险。减少这种人为造成的死亡率对该种群的生存能力至关重要。
