Observations on belugas in Ulbansky Bay, the Okhotsk Sea

Observations on belugas in Ulbansky Bay, the Okhotsk Sea

24 December 2013

The research was conducted in the summer of 2011.


Ulbansky Bay composes the western shallow arm of Academy Bay in the Shantar region, Western part of The Okhotsk Sea. Aerial surveys demonstrated that in summer beluga whales (Delphinapterus leucas) concentrate here in numbers, sometimes exceeding a thousand of individuals.

 

In summer 2011, an expedition to study the beluga aggregation in the south-western part of Ulbansky Bay was organized. Incidentally, the sightings of other cetacean species in the study region were recorded. The work was conducted from a motorized inflatable boat, mostly, within 30 km radius from the apex of the bay; alternatively, visual observations were conducted from the territory of the fishing plant.

 

Beluga whales were present in the study area during the entire period of work. Belugas come to the bay in spring as soon as ice is dragged by current off the coast, and stay in the area at least till September. During our work period, belugas concentrated mainly within 10 km from the Ulban, Elgo, Syran river mouths. However, we regularly observed medium-sized groups of whales (up to 30 individuals) moving along the coast by the fishing plant in both directions. It is possible to conclude that, in spite of the high concentration near the river mouths, belugas also move over the entire study area. The number of observed whales varied; the highest number of individuals was recorded in the last week of July, when increase in number of the newborns was also noticed.

 

In the first days of August, upon the end of pink salmon run, thenumber of whales in the river mouths has decreased: most of belugas spread along the coast in active search of fish. Major observed types of behavior were feeding, movement, socializing, play. Once, escape from the killer whales was observed: belugas were moving fast along the coast in the swell zone. Also, a badly injured – probably, be a killer whale – beluga was photographed. Unlike in Sakhalinsky and Nikolaya Bays, where belugas are very shy, in Ulbansky Bay the whales expressed a keen interest to humans and vessel by approaching and touching the boat, engine propeller, human arm. The comparison of beluga photographs from three bays has shown the higher frequency of skin lesions in Ulbansky Bay. The differences in behavior and the state of skin suggest that in Ulbansky Bay we deal with a separate aggregation.

 

Shpak O. (1), Paramonov A. (2)

 

1. A.N. Severtsov Institute of Ecology and Evolution RAS, Moscow, Russia


2. Dolphin and I‖, Ltd., Moscow, Russia

 

References:


Vladimirov V.L. 1994. Present distribution and abundance of whales in the Far Eastern seas. Marine biology, 20(1): 3-13


Tomilin A.G. 1962. Ceta-ceans of the USSR matine fauna. Moscow, 211 p.


Shulezhko T.S. 2008. Ecological types of killer whales of Russian part of the Pacific Ocean: photoidentification and acoustic analysis. PhD diss., Moscow, MSU. 197 pp.


Brownell R.L. jr, Clapham P.J., Miyashita T., Kasuya T.2001. Conservation status of North Pacific right whales. JCRM (spec. iss.) 2, pp. 269-286.


Burdin A.M., Hoyt E., Sato H, Tarasyan K.K., Filatova O.A. 2005. Resident and Transient-type Killer Whales, Or-cinus orca, in Southeast Kamchatka, Russia. IWC Report SC/56/SM15.


Shpak O., Meschersky I., Hobbs R., Andrews R., Glazov D., Chelintsev N., Kuznetsova D., Solovyev B., Nazarenko E., Michaud R., Mukhametov L. 2011. Current status of the Sakhalin-Amur beluga aggregation (The Okhotsk Sea, Russia): sustainability assessment. Report for 2007-2010 stages: Results of 4 years of study and preliminary conclusions. Report submitted to IUCN Independent Scientific Review Panel, Chicago, 6-7 March, 2011. 68 pp. (excl. att.).