Lilia Dmitrieva, Caspian seal ecology and conservation
The Caspian seal (Pusa caspica) is a small-bodied, ice-breeding phocid, endemic to the landlocked Caspian Sea in Central Asia. The species is listed as ‘Endangered’ by the International Union for the Conservation of Nature (IUCN), having declined by around 90% from a population exceeding 1 million individuals at the start of the 20th century, primarily due to unsustainable hunting. It is now subject to a range of threats including high levels of mortality from fishing by-catch and other anthropogenic sources, and habitat loss and disturbance caused by industrial and urban development. Little was known about its’ movement and dive patterns, until a group of scientists from Estonia, Kazakhstan, Russia and the UK deployed 75 Argos satellite tags on Caspian seals from 2009 to 2012. Their results, originally published in the Marine Ecology Progress Series, “Individual variation in seasonal movements and foraging strategies of a land-locked, ice-breeding pinniped,” provide valuable data to support conservation efforts in the region, as this adaptation of their article points out.
A Caspian seal about to be released after tagging with a Wildlife Computers SPOT tag.
This work was conducted by an international team of European, Russian and Kazakh researchers, (Caspian International Seal Survey (CISS)), who have been interested in Caspian seal ecology and conservation since 2004. The lead author of the paper is Dr. Lilia Dmitrieva, a post-doctoral research fellow in marine mammal ecology at the University of Leeds, UK, working with the programme leader Dr. Simon Goodman. Dr. Goodman’s research spans marine mammal ecology, conservation biology, and population genetics, and he is a member of IUCN Pinniped Specialist Group. The team would like to thank Agip KCO and NCOC for financial support under the North Caspian Sea Production Sharing Agreement
(NCSPSA) Venture, which made the work possible.
From left to right, Kobey Karamendin, Mart Jussi, Lilia Dmitrieva, Simon Goodman, Timur Baimukanov, Yermukhammet Kassymbekov.
Example tracks for Caspian seals tagged in April 2011 showing some of the variation in migration patterns observed. Left seals which made long distance movements into the mid and southern Caspian, right seals which remained in the northern Caspian for the whole deployment period April 2011-April 2012
Crucial data for conservation
Intensive human activity throughout the Caspian, including fishing, oil and gas extraction, shipping and coastal development overlap with the seal movements identified here. A seal ‘migration corridor’ along the Kazakh coast connecting the north-east and mid-Caspian overlaps with intensive shipping and fishing activity. Areas used by seals along the western coast also overlap with commercial fishing grounds. The north Caspian, which is an important year round habitat used for moulting, transit, foraging, resting and breeding, is an area of intensive oil and gas development and also has high levels of sturgeon poaching activity which generates substantial bycatch of seals (Dmitrieva et al. 2013). In view of these environmental pressures, Argos telemetry data can help assess impacts from human activities and contribute to conservation measures such as defining protected area which encompass critical habitats for Caspian seals.