Sea of Azov IMMA
Size in Square Kilometres
36 851 km2
Qualifying Species and Criteria
Black Sea harbour porpoise – Phocoena phocoena relicta
Criterion A, B(2), C(2), D(1)
Marine Mammal Diversity
Phocoena phocoena relicta
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The IMMA occupies the whole Sea of Azov (except the Sivash lagoons) and includes waters between 0 and 14 m deep. The Sea of Azov is an important habitat area for marine life, including various fish species as well as a distinct population of the harbour porpoise (Phocoena phocoena relicta), which migrate into the sea during the summer reproductive season. The Azov porpoises in the Sea of Azov are distinct in their morphology, a larger body size and distinct skull shape and skull proportions, including a wider rostrum which can be better used for foraging near the sea floor. Therefore, they show a stable distinct morphological and ecological type. Fisheries strongly affect the Azov population. Numerous porpoise bycatch and stranding cases (including neonates) are recorded from this area, and the population size is estimated to have decreased by 60% between 2001 and 2013.
Description of Qualifying Criteria
Criterion A – Species or Population Vulnerability
The Sea of Azov is an important habitat for the endangered Black Sea harbour porpoise (Phocoena phocoena relicta) (Birkun, 2003; Gol’din, 2004; Birkun and Frantzis, 2008; Birkun and Krivokhizhin, 2011; Gol’din and Vishnyakova, 2015, 2016). Fisheries strongly affect the population status of the Azov Sea population of the Black Sea harbour porpoises. Numerous porpoise bycatch and stranding cases are recorded from this area (652 cases in 1999-2013 only from the southern coast strip 80 km long), and the population size is estimated to have decreased by 60% during 2001-13 (Vishnyakova and Gol’din, 2015a,b; Vishnyakova, 2017).
Criterion B: Distribution and Abundance
Sub-criterion B2: Aggregations
The Azov population of the Black Sea harbour porpoise inhabits the IMMA area during the warm season, usually from April to November (Savenko et al., 2013). The entire Azov harbour porpoise population was estimated by a single aerial survey in 2001 as 2,922 (1,333–6,403; 95% CI) individuals, uncorrected for g(0) (Birkun and Frantzis, 2008): after correction, this estimate could be 13,500 individuals (Vishnyakova, 2017). During 2001-2013 harbour porpoise abundance, as estimated by modelling of population demography based on age structure, decreased by 60% and was estimated as at least 5,500 individuals (Vishnyakova, 2017). During the summer the porpoises form two major aggregations in the western and the eastern parts of the Azov sea, each of several thousand individuals (Birkun, 2003; Vishnyakova, 2017). The Sea of Azov is an important area for fisheries with high aggregations of anchovy, sand smelts, gobies and other fish species either permanently present or migrating to the productive feeding ground during summer (Zalkin, 1940; Drozdov, 2011). Once the Sea of Azov was considered as a particularly productive area within the Mediterranean realm, although its productivity declined during the 20th century (Drozdov, 2011).
Criterion C: Key Life Cycle Activities
Sub-criterion C1: Reproductive Areas
The Sea of Azov is the important reproductive area for the harbour porpoises because the porpoises are permanently present in the area during the mating and calving season (Gol’din, 2004; Savenko et al., 2013). Numerous neonate porpoises were recorded alive and dead in the southern Sea of Azov from April to September (Gol’din, 2004), and neonates were the most numerous age group in strandings, comprising more than 20% of the overall stranding record (Vishnyakova, 2017).
Criterion D: Special Attributes
Sub-criterion D1: Distinctiveness
The porpoises in the Sea of Azov are distinct in their morphology: they have larger body size than the Black Sea porpoises (Gol’din, 2004), and they are significantly different from Black Sea porpoises in their skull shape and skull proportions. This may be due to seasonal differences in feeding: Azov porpoises have a wider rostrum which shows clinorhynchy and thus can be better used for foraging near the sea floor (Gol’din and Vishnyakova, 2015, 2016). Therefore, they show a stable distinct morphological and ecological type within a certain isolated geographical area. In addition, the Azov porpoises differ in population demography from their Black Sea counterparts: they have a shorter life span (on average, 7 vs 10 years) which has been gradually decreasing since 1999 to 6.5 years in 2013 (Vishnyakova, 2017).
Birkun, Jr, A. 2003. Assessment of the state of the Red Book marine mammals populations of the Azov and Black Seas. In Final report on research work MS-2003. BREMA Laboratory, Ukraine. 222 pp. [In Russian]
Birkun, Jr., A.A. and Frantzis, A. 2008. ‘Phocoena phocoena ssp. relicta. The IUCN Red List of Threatened Species 2008: e.T17030A6737111’. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T17030A6737111.en.
Borovskaya, R.V. and Leksikova, L.A. 2008. ‘About the satellite information possibility using in the study of the Azov-Black Sea basin’. Proceedings of the Southern Scientific Research Institute of Fisheries and Oceanography, 46:138-144.
Drozdov, V.V. 2011. ‘Long-term variability of fishery resources of the Black Sea, tendencies, the reasons and prospects’. Uchenye zapiski RGGMU V 21:137-154.
Gol’din, P. 2004. ‘Growth and body size of the harbour porpoise, Phocoena phocoena (Cetacea, Phocoenidae), in the Sea of Azov and the Black Sea’.Vestinik zoologii 38(4):59-73.
Goldin, P.E. and Vishnyakova, K.A. 2015. ‘Differences in skull size of harbour porpoises, Phocoena phocoena (Cetacea), in the Sea of Azov and the Black Sea: evidence for different morphotypes and populations’. Vestnik zoologii 49(2):171–180.
Gol’din, P. and Vishnyakova, K. 2016. ‘Habitat shapes skull profile of small cetaceans: evidence from geographical variation in Black Sea harbour porpoises (Phocoena phocoena relicta)’. Zoomorphology 135(3):387–393.
Savenko, O., Vishnyakova, K., Gladilina, E. and Goldin, P. 2013. ‘Fish, temperature, visual and acoustic monitoring: discovering seasonal migration patterns of harbour porpoises in the Sea of Azov’. In Abstracts of the 20th Biennial Conference on the Biology of Marine Mammals. Dunedin, New Zealand, 9–13 December 2013, p.188.
Vishnyakova, K.O. 2017. The harbor porpoise (Phocoena phocoena) in the Sea of Azov and the north-eastern Black Sea: population morphology and demography. Dissertation submitted for the completion of the degree of Candidate of Sciences in Biology, qualification 03.00.08, zoology. Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine. Kiev. State Of Biological Resources Of The Black And Azov Seas (Reference Book). 1995. pp.1-64. Kerch: YugNIRO.
Vishnyakova, K. and Gol’din, P. 2015a. ‘Seasonality of strandings and bycatch of harbour porpoises in the Sea of Azov: the effects of fisheries, weather conditions and life history’. ICES Journal of Marine Science 72(3):981–991.
Vishnyakova, K. and Gol’din, P. 2015b. ‘Cetacean stranding rate correlates with fish stock dynamics: Research of harbour porpoises in the Sea of Azov’. Marine Biology 162:359–366.
Vishnyakova, K.A., Savenko, O.V., Oleinikov, E.P., Gladilina, E.V., Gorohova, V.R. and Gol’din, P.E. 2013. ‘Shift of terms of spring migration of harbor porpoises in the Kerch Strait and north-eastern Black Sea in 2011-2012’. Trudy YugNIRO 51:32-35.
Vishnyakova, K. and Gol’din, P. 2016. Data on cetacean strandings (1999 – 2013) on the Ukrainian coast of the Black Sea and the Sea of Azov and adjoining areas. v1.3. Ukrainian Scientific Centre of Ecology of the Sea (UkrSCES). Dataset/Occurrence. http://gp.sea.gov.ua:8082/ipt/resource?r=cetacean_strandings_data_bs_as&v=1.3 https://doi.org/10.15468/idrmoa accessed via GBIF.org on 2021-02-25.
Vishnyakova, K., Savenko, O., Gladilina, E., Gol’din, P. and Neprokin, O. 2017. Data on cetacean strandings on the Ukrainian coast of the Black Sea (2017). v1.6. Ukrainian Scientific Centre of Ecology of the Sea (UkrSCES). Dataset/Occurrence. http://gp.sea.gov.ua:8082/ipt/resource?r=strandings2017&v=1.6
Zalkin, V.I. 1940. ‘Some observations on the biology of dolphins in the Azov and Black Seas’. Bul. Moscow society testing nature. Dept. Biol., 49(1):61-70 [In Russian].