Survey data summary.

Number of beaked whale groups detected, and total km of survey effort (Lt) in each year of cetacean line-transect surveys. Only whale groups *Effort in these years are from three survey strata only (i.e., Oregon-Washington stratum not surveyed in these years).本数据集收录了鲸类线样调查（cetacean line-transect surveys）各年度的喙鲸（beaked whale）群检出数量，以及调查总航程（记为Lt，单位：千米）。对应年份中，仅喙鲸群相关的调查工作量（*Effort）来源于三个调查层（survey strata），即该年度未开展俄勒冈-华盛顿调查层（Oregon-Washington stratum）的调查工作。