Summary
A state-space model, using the Jolly-Seber assumption about population entry, was used to characterize the changing abundance of North Atlantic right whales (Eubalaena glacialis) between 1990 and 2015. Estimates from this modeling approach were only slightly higher than published values, except for the most recent years (capture rates substantially declined). North Atlantic right whale abundance increased about 2.8%/annually from the median estimate of 270 individuals in 1990 to 483 in 2010, followed by a decline to 458 in 2015. There is evidence of diverging abundance trends between sexes, a result of reduced survival of females.