Caspian Seal Breeding Area IMMA

Criterion A – Species or Population Vulnerability

The Caspian seal is endemic to the Caspian Sea and is listed as Endangered by IUCN (Goodman & Dmitrieva 2016), and in the Red lists of all 5 littoral states (Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan). Since it is landlocked within the Caspian Sea it has no possibility to migrate to alternate areas, and therefore is entirely dependent on the Caspian environment.

The IMMA encompasses the habitat (the winter ice field of the north-east Caspian) used by the entire breeding population of Caspian seals to give birth, raise pups to weaning and to mate. The winter ice-field is therefore crucial to the survival of the species. Unsustainable hunting of adults (mainly females) and pups on the ice field from the 19th century to the 1990s resulted in collapse of the species population (Badamnshin 1961), estimated at 1–1.6 million in the mid-19th century, to around 100,000 individuals by 2005 (Härkönen et al. 2012). This decline, 90% since the mid-19th century, demonstrates the extreme vulnerability of the species. The species’ long-term viability depends on the physical characteristics of the northern ice field and on the breeding seals being free from hunting, shipping, or other forms of anthropogenic disturbance.

Criterion B: Distribution and Abundance

Sub-criterion B2: Aggregations

The Caspian Seal breeding population on the ice was surveyed annually from 2005 to 2012 (Härkönen et al. 2008; Dmitrieva et al., 2015).  The minimum estimate for the number of pups born on the ice has ranged from ~8,000–9,000 in years 2007–2008 and 2010 and between ~22,000 and 34,000 in years 2005–2006, 2009 and 2011–2012. These figures may be compared with estimates of pup production from the 1980s of 50,000–90,000 (Krylov, 1990), although the methodology for these earlier estimates is not clear (see Härkönen et al., 2012).  The minimum estimate for the number of adults on the ice has ranged from ~14,000 in 2010, ~32,000 in 2008, ~40,000 in 2005–2006, 53,000 in 2011 to ~63,000–67,500 in 2005, 2009 and 2012 (Dmitrieva et al. 2015).

The boundaries of the IMMA were defined primarily on the maximum geographic extent of the distribution of breeding seals observed in transect based aerial surveys conducted between 2005 and 2012 (Dmitrieva et al. 2015). The ice coverage in these survey years ranged from above average to very poor and so the extent can be taken as representative of the current ice regime. The southern boundary was extended beyond the distributions observed by Dmitirieva et al. (2015) to allow for ice extent greater than occurred in the 2005-2012 period, but which is known to occur occasionally from remote sensing data. The north eastern boundary was extended to the coast to allow years with minimal sea ice cover, during which seals are forced to pup on remnants of land-fast ice. Such years are likely to be more frequent under projected climate heating.

Criterion C: Key Life Cycle Attributes

Sub-criterion C1: Reproductive Areas

The main area for reproduction is the north Caspian winter ice-field (Härkönen et al. 2008; Dmitrieva et al. 2015). A core area in the general location known as “the Saddle” (Figure 1) has been most often frequented by mother-pup pairs in years when stable ice has covered this sea area. In other years, females have given birth close to the ice edge or on ice floes (Wilson et al. 2017b). 

Mating also takes place in the winter ice field from late lactation to the post-pupping period. Individual males have been observed approaching females accompanied on the ice by their well-grown young. Male-female pairs have also been observed on the edge of large polynias during the immediate post-pupping period (late February to early March). Mating appears to take place in the water, either beneath the ice or in polynias (Wilson et al. 2017b).