Updated population viability analysis, population trends and PBRs for Hector's and Maui dolphin

Abstract

EXECUTIVE SUMMARYUpdated population viability analyses, incorporating the latest abundance and bycatch data indicate that: O_LIThe estimated population decline for Maui dolphin is 2% per year C_LIO_LIThere is a 68% probability that the population is continuing to decline C_LIO_LIAfter 30 years (6 more surveys) statistical power of detecting this rate of decline would be < 15% C_LIO_LIOnly very large declines (37%) and recovery (45%) would be detectable with 80% statistical power after 30 years (6 more surveys) C_LIO_LIThe level of conservation threat for Hectors dolphin remains high despite a recent, larger population estimate off the east coast of the South Island C_LIO_LIIncreased overlap between dolphins and fisheries, due to more extensive offshore distribution of dolphins off the South Island east coast, more than offsets the apparently higher population size C_LIO_LIThe Hectors dolphin population has declined 70% over the last 3 generations, exceeding the 50% threshold for Endangered C_LIO_LIPopulation declines are predicted to continue under current protection levels C_LIO_LIThe results of this research are consistent with: {bigcirc}NOAA proposal to list Hectors and Maui dolphins under the US Endangered Species Act {bigcirc}IWC recommendation to ban gillnets and trawling throughout Maui dolphin habitat {bigcirc}IUCN recommendation to ban gillnets and trawling throughout Hectors and Maui dolphin habitat C_LI