Infection with Brucella spp., long known as a cause of abortion, infertility, and reproductive loss in domestic livestock, has increasingly been documented in marine mammals over the past two decades. We report molecular evidence of Brucella infection in Asian sea otters (Enhydra lutris lutris). Brucella DNA was detected in 3 of 78 (4%) rectal swab samples collected between 2004 and 2006 on Bering Island, Russia. These 78 animals had previously been documented to have a Brucella seroprevalence of 28%, markedly higher than the prevalence documented in sea otters (Enhydra lutris) in North America. All of the DNA sequences amplified were identical to one or more previously isolated Brucella spp. including strains from both terrestrial and marine hosts. Phylogenetic analysis of this sequence suggested that one animal was shedding Brucella spp. DNA with a sequence matching a Brucella abortus strain, whereas two animals yielded a sequence matching a group of strains including isolates classified as Brucella pinnipedialis and Brucella melitensis. Our results highlight the diversity of Brucella spp. within a single sea otter population.
Despite the growth in knowledge about the effects of a warming Arctic on its cold-adapted species, the mechanisms by which these changes affect animal populations remain poorly understood. Increasing temperatures, declining sea ice and altered wind and precipitation patterns all may affect the fitness and abundance of species through multiple direct and indirect pathways. Here we demonstrate previously unknown effects of rain-on-snow (ROS) events, winter precipitation, and ice tidal surges on the Arctic's largest land mammal. Using novel field data across seven years and three Alaskan and Russian sites, we show arrested skeletal growth in juvenile muskoxen resulting from unusually dry winter conditions and gestational ROS events, with the inhibitory effects on growth from ROS events lasting up to three years post-partum. Further, we describe the simultaneous entombment of 52 muskoxen in ice during a Chukchi Sea winter tsunami (ivuniq in Iñupiat), and link rapid freezing to entrapment of Arctic whales and otters. Our results illustrate how once unusual, but increasingly frequent Arctic weather events affect some cold-adapted mammals, and suggest that an understanding of species responses to a changing Arctic can be enhanced by coalescing groundwork, rare events, and insights from local people.