Monitoring of beluga whales in Khairuzova, Belogolovaya, Moroshechnaya rivers

Monitoring of beluga whales in Khairuzova, Belogolovaya, Moroshechnaya rivers

8 July 2013

Monitoring the distribution characteristics of beluga whales in the Khairuzova, Belogolovaya and Moroshechnaya rivers, western Kamchatka, in summer 2010-2011.

In June-July, 2010 within the framework of the White Whale Programme directed on the study of the abundance and distribution of beluga whales in the Russian coastal waters a pilot research of the Western Kamchatka coast was carried out, which showed that in summer the estuary of Khairuzova and Belogolovaya rivers is the best place to organize stationary observations on the species. In August, 2010 the first research in the given area was conducted and in summer 2011 the data on beluga whales summering in the Moroshechnaya river, located 40 km to the south from the estuary of the Khairuzova and Belogolovaya rivers, were also obtained. Here we discuss some features of the beluga whale distribution in the waters of the above-mentioned rivers. 

The research was carried out in the period of 30 July – 31 August, 2010 in the estuary of the Khairuzova and Belogolovaya rivers and in the period of 17 August – 13 September, 2011 in the downstream of the Moroshechnaya river. The estuaries of all rivers are formed by a few channels and a littoral drying up during low tides. The average depth of the main channels varies from 2 to 6 meters. The tides are irregular, semidiurnal, a tidal rise reaches up to 5 meters. The observations were carried out from several onshore points, as well as from a boat, using a standard for cetacean re-search methods.


According to the obtained data the main part of the activity of beluga whales in the rivers consists of the behavior directed on foraging and feeding on salmon. Social behavior is quite rare. Most of the beluga whales enter the river during high tides. A considerable num-ber of animals stay for hunt in the widest part of the river – estuary, where we observed up to 250 animals in the Khairuzova and Belogolovaya rivers and about 111 animals in the Moroshechnaya river. In the estuaries beluga whales spread over a vast water area, prefer-ring its deepest parts accessible both during high and low tides. During a low tide most of the animals return back to the sea. Sometimes beluga whales fail to leave the shallow waters on time: in 2010 three whales were found stranded on the dried-up part of the Khairuzova river by fishermen. During a high tide they managed to return back to the sea.


Having entered the river, some animals don't stay in the estuary but move upstream, where they stay in some particular but not numerous places. The ― "Barzha" area in the Khairuzova river and ―"Bukhta" in the Moroshechnaya river can serve as an example of such places. We regularly observed up to 23 whales in the ― "Barzha" area and up to 33 individuals in the ―"Bukhta" area. In both places beluga whales were constantly found irrespective of the water level and flow direction: here we observed animals during high tide as well as during low water.


Most of the animals were young individuals and females with calves: 17.5% of belugas from the ―Barzha‖ area were presented by young grey animals 3-4 years old, while 5.9% were presented by dark-grey calves less than 1 year old. In the ―"Bukhta" area 12.2% of belugas were presented by young individuals and 4.6% – by calves. Active hunt on fish dominated over all other types of behavior (travelling, resting and socialization) and occupied 51.3% of the animal time budget in the ― "Barzha" area and 56.5% - in the ―"Bukhta" area. According to photoidentification some animals visited these areas regularly: 88% of belugas identified in the ― "Barzha" area and 28% of belugas from the ― "Bukhta" area were encountered more than once. Besides, in these areas during hunting on salmon beluga whales were characterized by relatively high vocal activity.


The obtained data raised the following question: what features do the river areas preferred by belugas possess? It is known that a big number of anadromous and semi-anadromous fish species spawn in the basin of the Khairuzova, Belogolovaya and Moroshechnaya rivers: smelt, coho salmon, pink salmon, sock-eye salmon, chinook salmon, mikizha, malma trout, kundscha and others. Most anadromous fish species are characterized by similar migration dynamics. Having approached the river, the fish gather in the freshening zone at the entrance to the estuary. When their number reaches some critical value, the fish enters with the tide the estuary and moves along the river shores upstream in dense schools. The current, carrying chemical mark-ers which help salmon to recognize their spawning grounds, is one of the key factors determining the trajectory of the moving school. Thus, the river parts where the river channel carrying the main water masses narrows, serve as gates slowing down the fish going upstream. As a result, the number of fish in such places is higher than in other parts of the river. Therefore, the parts of the river preferred by belugas may be connected with the river bends where the channel narrows and approaches the shores. The area of the Khairuzova river, named ― "Barzha", as well as ―"Bukhta" in the Moroshechnaya river, present such river bends located a few kilometers up the estuary. Here the channel of the river narrows and is located close to one of the shores. The rest of the river range is presented by a vast sandbank, drying up during the low tide. According to our observations in the above-mentioned areas during the mass migration salmon gather close to the shore attracting beluga whales.


We suppose that some beluga whales can explore such suitable and abundant with fish places like ― "Barzha" and ― "Bukhta" and stay there for the whole period of the salmon mass migration for feeding and, probably, for teaching young animals to hunt, while other whales don't stay in any particular places and leave the rivers with the low tide. In this connection the research directed on the study of the hydrological characteristics of such areas, their number in the rivers of the Western Kamchatka, the constancy and duration of their usage by belugas during summer period, as well as the role of these areas in successful feeding of females with calves and young animals is of a great interest.


It is important to notice that beluga whales summering in the Khairuzova, Belogolovaya and Moroshechnaya rivers are extremely careful and don't let boats approach nearer than 10-30 meters. It might be connected with the presence of a considerable number of fisher-men in the area. It is also possible that fishermen use guns to frighten off beluga whales from nets in the places abundant with fish – scars found on some animals prove this idea. Nevertheless, all places preferred by beluga whales are located in the navigable parts of the rivers.


The research is being conducted as a part of the Russian Academy of Sciences Permanent Expedition's work to study the animals of the Russian Federation included in the Red List and other particularly important species of the Russian fauna and is supported by the Russian Geographical Society. The authors ex-press their sincere gratitude to the participants of the White Whale Programme: Dolgov D.B., Dorofeev D.S., Ivanov D.I., Koshel V.E., Mamaeva I.V., Maistrenko P.A., Udovik D.A., Chaschina E.K. and Shevelev A.I. for their help in the organization of the research, gathering and processing of the data.


1. Kamchatka Branch of the Pacific Geographical Institute, RAS, Petropavlovsk-Kamchatsky, Russia


2. Severtsov Institute of Ecology and Evolution, RAS, Moscow, Russia


3. Kronotsky State Biosphere Reserve, Elizovo, Russia


Shulezhko T.S.(1), Tarasyan K.K.(2), Kazansky F.V.(3), Glazov D.M.(2), Rozhnov V.V.(2)