A 10-year-old female sea otter exhibited convulsions, arrhythmia, hyperthermia, forced breathing and anorexia and died after a week. Histopathological examination revealed neoplastic proliferation of small round cells with scant cytoplasm and round or oval nuclei distributed mainly in the thalamus. The proliferation of neoplastic cells was observed in the cerebral parenchyma and perivascular ar...

The presence and strength of trophic cascades can be a function the local abiotic environment relative abundance key species. reintroduction expansion sea otters Enhydra lutris , known keystone species in kelp ecosystems, southeast Alaska provides rare natural experiment to test generality apex‐predator – seagrass across broad spatial scale. We conducted an in‐depth community survey at 21 sites...

Shifts between the alternate stable states of sea urchin barren grounds and kelp forests correspond to density. In Aleutian Archipelago, green urchins Strongylocentrotus polyacanthus are dominant herbivores that graze forests. Sea recruitment is an important driver influences density, particularly in absence top-down control from a keystone predator such as otter Enhydra lutris . To understand ...

Sea otter (Enhydra lutris) populations in southwest Alaska declined substantially between about 1990 and the most recent set of surveys 2015. Here we report changes distribution abundance sea otters, covarying patterns reproduction, mortality, body size condition, diet foraging behavior, food availability, health profiles, exposure to environmental contaminants over this 25-yr period. The popul...