Sakhalin monitoring shows long‑term visitors but suggests industrial disturbance may depress local counts

A pre‑recorded presentation from Alexander (Sasha) Berdine summarized monitoring of western grey whale feeding grounds off Sakhalin and Kamchatka. Berdine reported multi‑decadal photo‑ID catalogs (hundreds of unique individuals and thousands of encounters) and described a core group of long‑term visitors that return for decades.

Berdine noted downward trends in local counts and shorter durations of stay for females in some feeding areas. He identified anthropogenic factors — notably seismic surveys and oil‑production activity — as likely contributors to local declines in the Sakhalin study area and urged continued monitoring of offshore and northern areas. "Two oil drilling platform was mounted in close proximity of grey whale feeding area in 1998 and 2007," the presentation stated, and presenters cautioned that offshore data gaps limit inference about regional population change.