Cetaceans of the Mediterranean and Black Seas: State of Knowledge and Conservation Strategies SECTION 14 Disturbance to Cetaceans in the Black Sea Alexei Birkun, Jr. Laboratory of Ecology and Experimental Pathology, S.I. Georgievsky Crimean State Medical University, Lenin Boulevard 5/7, Simferopol, Crimea 95006, Ukraine - [email protected] To be cited as: Birkun A., Jr. 2002. Disturbance to cetaceans in the Black Sea. In: G. Notarbartolo di Sciara (Ed.), Cetaceans of the Mediterranean and Black Seas: state of knowledge and conservation strategies. A report to the ACCOBAMS Secretariat, Monaco, February 2002. Section 14, 7 p. A Report to the ACCOBAMS Interim Secretariat Monaco, February 2002 With the financial support of Coopération Internationale pour l’Environnement et le Développement, Principauté de Monaco Introduction The Strait of Bosphorus (about 30 kilometres long, 750-3700 metres wide and 37-124 metres The disturbance is mentioned as a limiting deep in the midstream), along with the Marmara factor for Black Sea cetacean populations in few Sea and Dardanelles, is a single marine path in- publications (Birkun et al. 1992, Birkun and terconnecting the Mediterranean and Black Seas. Krivokhizhin 1996 c 2001, Öztürk 1999) based The strait and adjacent areas are abundant in har- on a general, quite approximate understanding of bours, piers, ferry stations and anchorages asso- the problem. Until now no special research pro- ciated to the Istanbul megalopolis. Intensive ject has investigated human activities (other than lengthwise and transverse traffic and swift cur- direct killing, fishery, pollution and maintenance rents make navigation difficult here and cause in captivity) likely to disturb marine mammals in continual threat of collisions. Some 40,000 ships this maritime area. There are no systematic data passing through the Bosphorus annually, and in- on effects of man-made noise and vessel colli- numerable local smaller craft, can put obstacles sions on cetaceans. At the same time it is clear in the way of migratory animals (Zaitsev 1998). that potential sources of disturbance exist. Harbour porpoises, bottlenose and common dol- phins are known to visit this narrow strait (Öz- türk and Öztürk 1997) moving between neigh- Maritime traffic bour ing seas. It is supposed that a number of ce- taceans passing through the Bosphorus has a It is evident that the shipping lanes crossing trend to decrease from year to year due to heavy the Black and Azov Seas in various directions maritime traffic forming a barrier to the migra- (Fig. 14.1) coincide with cetacean habitats and tion (Öztürk 1999). migration pathways. Traffic is more concen- Another marine biological corridor and at the trated in coastal waters over the continental shelf; same time an important shipping junction is the thus, shipping impact on both inshore species – Strait of Kerch (41 kilometres long, 4-15 kilome- harbour porpoise (P. phocoena) and common tres wide and up to 15 metres deep in the fair- bottlenose dolphin (T. truncatus) – seems to be way), which links the Sea of Azov and the Black having a more pronounced influence than on off- Sea. Two port complexes are situated along the shore short-beaked common dolphin (D. delphis). Ukrainian and Russian shores of the strait. They Traffic density has a strong tendency to increase are connected by ferry line and operate the whole in the areas close to harbours; therefore, the le v- year. About 10,000 vessels sailing through the els of operational activity of the existent ports strait each year are considered as a source of dis- may be adopted as a major criterion for the esti- turbance for migrating fishes (Zaitsev 1998). All mation of their disturbing capability. three species of Black Sea cetaceans were de- Among the numerous ports located in the scribed here in the past as well; also, a yearly Black Sea and adjacent waters, four harbour ag- movement is known of harbour porpoise herds glomerations and shipping lane crossings play from the Black Sea to the Sea of Azov in spring obviously the most important role in cetaceans and backwards before winter (Zalkin 1940, disturbance and could be denoted as the hot-spots Kleinenberg 1956). The presence of P. phocoena affecting cetacean distribution and migrations and T. truncatus in the strait has been confirmed (Fig. 14.1): in 1997 and 2001, whereas no D. delphis indi- viduals were sighted those years (Birkun and · The Bosphorus shipping junction with the Krivokhizhin 1998, Birkun et al. 2002). adjacent areas in the Black and Marmara In accordance with its transportation capac- Seas (Turkey); ity, the north-western harbour agglomeration is · The Kerch Strait shipping junction with the the second shipping centre in the Black Sea adjacent areas in the Black and Azov Seas subregion after Bosphorus junction. It includes a (Russia and Ukraine); series of ports in the Odessa province of Ukraine · The North-western harbour agglomeration and also marine and river transport facilities in including ports in Odessa Bay and estuaries the estuaries of Dnieper, Dniester and South of Dnieper, Dniester and South Boug rivers Boug which are navigable rivers. In the late (Ukraine); 1990s the Odessa port complex handled almost · The North-eastern harbour agglomeration in- 30 million tons of cargo annually, and about 10 cluding ports in Taganrog Gulf, lower Don million tons of oil were exported each year and its delta (Russia and Ukraine). through its oil terminal (Bilyavsky et al. 1998). Cetaceans of the Mediterranean and Black Seas – 14.2 Cetaceans are well known in Odessa Bay and ad- Channel dredging and marine dumping of jacent waters (Bushuev et al. 2001), and some- removed sediments times occur inside the harbours with a risk for animals safety (B.G. Alexandrov, pers. comm.). An obvious source of disturbance for Black Harbour porpoises are not rare in the Dnieper and Sea harbour porpoises and bottlenose dolphins is South Boug estuaries, as well as in the Dnieper the dumping of bottom sediments removed due to itself and its lower tributaries (Selyunina 2001). the dredging of navigation canals and the recon- In 2000 a group of four common bottlenose dol- struction of ports. Dredging and dumping works phins was observed in the Dnieper above Kher- cause noise pollution and lead to the decline in son (S.M. Chorny, pers. comm.). water transparency, destruction and silting of The fourth hot spot – the north-eastern har- benthic biocoenoses, and, thereby, to the reduc- bour agglomeration – consists of Ukrainian and tion of cetacean foraging capabilities. These dis- Russian ports located in Taganrog Gulf of the turbing activities are more intense in the shallow Azov Sea and in the lower Don. Two main direc- waters of the north-western shelf of the Black tions of ship traffic converge here: one from the Sea, and also in the Azov Sea, estuaries of big Black Sea through the Kerch Strait and a second rivers (Danube, Dnieper, Dniester, South Boug, from the Russian large rivers and canal system Don, Kuban) and Kerch Strait. According to linking the Sea of Azov with the centre of Euro- Bilyavsky et al. (1998), there are more than 30 pean Russia, the Caspian and Baltic Seas. Local dumping sites in the Black Sea coastal zone, and ports operate mainly during the warm season be- ten of them are in the north-western area, where cause of unfavourable ice conditions in winter. five million cubic metres of soil have been The harbour porpoise is the only cetacean species dumped annually by the USSR (since 1963) and known in these almost fresh waters; occasionally Ukraine (since 1991). In the Kerch Strait 21 mil- it was observed in the Don river (Geptner et al. lion cubic metres of soil were dumped from 1991 1976). to 1997. In Romania from the mid 1980s to mid In addition to the clusters of harbours men- 1990s up to 6-7 million cubic metres of sedi- tioned above, other shipping facilities can be a ments have been removed each year in order to source of heightened disturbance of the cetace- enlarge the port of Constantza, and about one ans. These include especially the multi-activity million cubic metres were dredged annually from ports located in Varna (Bulgaria), Constantza the entry of the Sulina channel connected with (Romania), Danube Delta (Romania and the Danube (Petranu 1997). The rate of sediment Ukraine), Sevastopol (Ukraine, with the base of accumulation at Black Sea dumping sites exceeds Russian Black Sea Navy), Novorossiysk (Rus- the natural sedimentation rate by more than 1000 sia), Batumi (Georgia), Trabzon, Samsun and times (Bilyavsky et al. 1998). Zonguldak (Turkey) (Fig. 14.1). The shipping in the Black Sea has an annual tendency to increase from spring to autumn with Sand extraction a summer maximum due to the sharp enhance- ment of small scale cabotage traffic and marine Sand extraction from the sea bottom for the tourism. Most domestic and international pas- building industry is widespread in the north- senger lines operate in the warm season only. western Black Sea shelf, the Sea of Azov and in Peaks of fishing fleet navigation occur in spring- some other sites (e.g., entrance to Donuzlav Lake early summer (gill net fishery) and autumn (pe- in the Crimea). As a disturbing factor this activ- lagic trawling). According to economic indices ity is similar to the dredging mentioned above, (Bilyavsky et al. 1998, Kerestecioglu et al. but it does not result in marine dumping. Mil- 1998), the highest level of Black Sea marine traf- lions tons of the sand are extracted in Dzharyl- fic intensity has been achieved in 1985-1992, gachsky, Karkinitsky and Tendrovsky bays and subsequently decreasing till the mid 1990s. from Odessa, Dniester and Shagany sandy banks However, further development of shipping facili- located in Ukrainian waters (Zaitsev 1998).