Seasonal movements of western gray whales Eschrichtius robustus between the feeding areas on the northeast coast of Sakhalin Island (Russia) in 2002 - 2006

The study area covered the northeastern part of Sakhalin Island, Russia. Photo-identification of the Korean-Okhotsk gray whale Eschrichtius robustus was conducted in summer-fall 2002-2006. The feeding areas included the nearshore area seaward of Piltun spit (Piltun area) and an area offshore of Chayvo Bay (Offshore area). The photo-identification study was mostly concentrated in these two areas but took advantage of opportunistic sightings outside these regions. In 2005 gray whales were observed in two new areas: an area adjacent to Levenshtern Cape (Northern Area) and Elizabeth area in Severny Bay. No sightings were recorded in these areas in the following years. In 2006 more focus was placed on the nearshore region seaward of Chayvo spit where whales were sighted for the first time at depths 12-15m. During the 5 years of observation in Offshore area, utilization by gray whales varied. Significant numbers of whales were observed in the Offshore area in 2002 and 2003. Abundance of gray whale was recorded much lower in 2004 and 2005. From 2002-2006, 63 whales were identified in both the Offshore and Piltun areas both in the same year and in different years.