Aerial surveys of pinniped populations at the Channel Islands National Park and National Marine Sanctuary, 1983

We documented the seasonal distribution and relative abundance of pinnipeds at the islands of the Channel Islands National Park (CINP, San Miguel, Santa Rosa, Santa Cruz, Anacapa, and Santa Barbara Islands) by conducting seasonal aerial surveys (Table I). These surveys were conducted at times that are, biologically, of greatest importance in detecting long-term changes in distribution and relative abundance. The primary use of these data for northern fur seals, California sea lions, and northern elephant seals is in examining distribution of these species at each island and not in providing estimates of natality or pup production. Data on pup production, pregnancy rates, survival, etc. are more reliably obtained by other methods and we have collaborated in summarizing those methods elsewhere (DeMaster et al. 1984). Aerial surveys of harbor seals appear to be the best (and most cost-effective) method for documenting relative population size on each island and for examining long-term trends in population abundance and distribution. 1984 Contract no. NOAA/83-ABC-00136 NMFS (National Marine Fisheries Service) SWFSC (Southwest Fisheries Science Center) Library Public Domain 1930