Data from: Evaluating anthropogenic threats to endangered killer whales to inform effective recovery plans

Understanding cumulative effects of multiple threats is key to guiding
effective management to conserve endangered species. The critically
endangered, Southern Resident killer whale population of the northeastern
Pacific Ocean provides a data-rich case to explore anthropogenic threats
on population viability. Primary threats include: limitation of preferred
prey, Chinook salmon; anthropogenic noise and disturbance, which reduce
foraging efficiency; and high levels of stored contaminants, including
PCBs. We constructed a population viability analysis to explore possible
demographic trajectories and the relative importance of anthropogenic
stressors. The population is fragile, with no growth projected under
current conditions, and decline expected if new or increased threats are
imposed. Improvements in fecundity and calf survival are needed to reach a
conservation objective of 2.3% annual population growth. Prey limitation
is the most important factor affecting population growth. However, to meet
recovery targets through prey management alone, Chinook abundance would
have to be sustained near the highest levels since the 1970s. The most
optimistic mitigation of noise and contaminants would make the difference
between a declining and increasing population, but would be insufficient
to reach recovery targets. Reducing acoustic disturbance by 50% combined
with increasing Chinook by 15% would allow the population to reach 2.3%
growth.