Editing Sea of Azov (section)

===Migrating and invading species===
[[File:Rapana Black Sea 2008 G1.jpg|thumb|''[[Veined rapa whelk|Rapana venosa]]'' from the Black Sea.]]
Some ichthyofauna species, such as [[anchovy]], [[garfish]], Black Sea [[merlangius merlangus|whiting]] and [[Esox|pickerel]], visit the Sea of Azov from the Black Sea for spawning. This was especially frequent in 1975–77 when the salinity of the southern Sea of Azov was unusually high, and additional species were seen such as [[bluefish]], [[turbot]], chuco, [[spurdog]], [[Salmo labrax|Black Sea salmon]], [[mackerel]] and even [[corkwing wrasse]], rock hopper, [[European bullhead|bullhead]] and [[eelpout]]. Unlike the Black Sea plankton which does not adapt well to the low salinity of the Sea of Azov and concentrates near the Kerch Strait, fishes and invertebrates of the Black Sea adjust well. They are often stronger than the native species, are used to the relatively low temperatures of the Black Sea and survive winter in the Sea of Azov well.<ref name=k84>Kostianoy, pp. 83–85</ref>

''[[Balanus improvisus]]'' is the first benthos species which spread from the Black Sea in the early 20th century and settled in the Sea of Azov. Its current density{{clarify|date=November 2024}} is 7&nbsp;kg/m<sup>2</sup>. From 1956, ''[[Veined rapa whelk|Rapana venosa]]'' is observed in the Sea of Azov, but it could not adjust to low salinity and therefore is limited to the neighborhood of the Kerch Strait. Several Sea of Azov mollusks, such as [[shipworm]] (''Teredo navalis''), [[soft-shell clam]] (''Mya arernaria''), [[Mediterranean mussel]] (''Mytilus galloprovincialis'') and ''Anadara inaequivalvis'', originate from the Black Sea. Another example of invading species is the Dutch crab ''[[Rhithropanopeus harrisii]]'' which is observed both in saline and freshwater parts.<ref name=k84/>

Formerly three types of dolphins, [[short-beaked common dolphin]], [[common bottlenose dolphin]] and [[harbour porpoise]], regularly visited the Sea of Azov from the Black Sea although the common dolphin usually avoided the basin and Kerch Strait due to low salinity.<ref>{{Cite iucn|url=https://www.iucnredlist.org/species/133729/3875256|title=The IUCN Red List of Threatened Species|access-date=2018-10-25}}</ref> One sub-species of harbour porpoise, ''Phocoena phocoena relicta'', used to live in the Sea of Azov and was therefore called "Azov dolphin" ({{lang|ru|азовка}}, azovka) in the Soviet Union. Nowadays, dolphins are rarely observed in the Sea of Azov. This is attributed to shallowing of the sea, increasing navigation activities, pollution, and reduction in the fish population.<ref>{{cite news|url=http://novosti.dn.ua/details/114488/|language=ru|date=19 February 2010|publisher=Novosti.dn.ua|title=Dolphins are leaving the polluted Sea of Azov}}</ref><ref>{{cite book |last=Klinowska |first=M. |url=https://books.google.com/books?id=QynOriR1MxEC&pg=PA89 |page=89 |title=Dolphins, porpoises and whales of the world: the IUCN red data book |publisher=IUCN |year=1991 |isbn=978-2-88032-936-5}}</ref>

Various species of [[pinniped]]s and [[beluga whale|belugas]]<ref>Anderson R.. 1992. [https://www.chicagotribune.com/1992/03/12/black-sea-whale-aided-by-activists/ Black Sea Whale Aided By Activists]. [[Chicago Tribune]]. Retrieved on April 21. 2016</ref> were introduced into Black Sea by mankind and later escaped either by accidental or purported causes. Of these, [[grey seal]] has been recorded within Kerch Strait and Sea of Azov.<ref>{{Cite web|url=https://www.researchgate.net/publication/235948607|title=Grey seal Halichoerus grypus in the Black Sea: The first case of long-term survival of an exotic pinniped|website=www.researchgate.net|accessdate=Jul 29, 2022}}</ref> [[Mediterranean monk seal]]s became extinct in the [[Black Sea]] in 1997,<ref name=iucn>{{cite iucn |author=Karamanlidis, A.|author2=Dendrinos, P.| title = ''Monachus monachus'' | volume=2015 | page = e.T13653A45227543 | year =2015 | doi = 10.2305/IUCN.UK.2015-4.RLTS.T13653A45227543.en }}</ref> and the historic presence of large whales such as [[minke whale]]s in the Black Sea is recorded,<ref name=GreekCetacea>{{cite web|year=2003|title=Current knowledge of the cetacean fauna of the Greek Seas|url=http://cetaceanalliance.org/download/literature/Frantzis_etal_2003.pdf|pages=219–232|access-date=2016-04-21|website=cetaceanalliance.org|archive-date=2008-09-07|archive-url=https://web.archive.org/web/20080907032339/http://www.cetaceanalliance.org/download/literature/Frantzis_etal_2003.pdf|url-status=dead}}</ref><ref name=BlackSeaWhales>{{Cite web |url=http://smena-online.ru/stories/kity-v-chernom-more |title=Киты в Черном море (cached) |access-date=2021-12-24 |archive-date=2019-02-03 |archive-url=https://web.archive.org/web/20190203170118/http://webcache.googleusercontent.com/search?q=cache%3ALvWTpr2qpQgJ%3Asmena-online.ru%2Fstories%2Fkity-v-chernom-more&num=1&hl=en&gl=nz&strip=0&vwsrc=0 |url-status=live }}</ref> although it is unclear whether these mammals historically occurred in the Azov basin.