The Black Sea mammal fauna has three species of cetaceans, which are endemic subspecies – the harbour purpoise, the short-beaked common dolphin and the bottlenose dolphin. The undermining of the forage base, poaching, accidental deaths in fishing nets, invasions of alien species, epizootics, pollution of the sea led to the threat of extinction of the Black Sea cetaceans in the 21st century. To overcome these factors, it is necessary to ban the use of three-wall trammel nets, to increase the fishing of introduced species, to test acoustic devices on nets to deter cetaceans, to award marine areas with protective status.
Causes and threats of decline in the number of cetaceans in the Black and Azov Seas
The Black Sea mammal fauna has three species of cetaceans, which are endemic subspecies:
• Black Sea short-beaked common dolphin (Delphinus delphis ponticus Barabash-Nikiforov, 1935),
• Black Sea bottlenose dolphin (Tursiops truncatus ponticus Barabash-Nikiforov, 1940),
• Black Sea harbour porpoise or phocene (Phocoena phocoena relicta Abel, 1905).
In addition, the harbour porpoise migrates during the warm part of the year to the Azov Sea, where bottlenose dolphins regularly occur. Marine mammals, as terminal predators, maintain the overall equilibrium of the marine ecosystems.
During the twentieth century, the number of cetaceans in the Black and Azov Seas has declined by at least five times due to the large scale commercial fishing conducted by the Black Sea countries until 1983. Cetaceans were caught for the sake of raw materials used for the manufacture of oils, paints, adhesives, varnishes, food, medicines, soaps, cosmetics, leather, and fertilizers. In addition, dolphins were caught for captivity. The dolphinarium on the Black Sea coast has been functioning since 1966.
Besides industrial catching, the undermining of the food base, poaching, accidental deaths in fishing nets, invasions of alien species, epizootics, pollution of the sea led to the threat of extinction of the Black Sea cetaceans. Thus, for harbour porpoises, the main contributors to the decline in numbers are the increase in fishing gear, especially bottom gill nets, including phantom fishing; reduction of fodder resources due to invasions of alien species, in particular the Mnemiopsis leidyi and the mollusc Rapana venosa, as well as the overexploitation of marine living resources in the 1980s; change of migratory routes of fish – forage objects due to construction of artificial structures; epizootics of different origins; marine pollution, including agricultural runoff, marine debris and underwater noise. The sources of underwater noise, in particular, may be construction (including bridges, tunnels, port facilities, wind power plants), seismic exploration for oil and gas production, drilling, and underwater explosions during military operations. For bottlenose dolphins, additional factors are illegal dolphin catches and collisions with ships. There are cases of accidental death of short-beaked common dolphins in trawl nets.
The cetaceans of Ukraine are under special legal protection because of their significant decline and threat of extinction. They are included in the Red Book of Ukraine, and according to the Law of Ukraine “On the Red Book of Ukraine”, the special use of cetaceans for profit, removal from the natural environment is prohibited. The special order of the Ministry of Environment (https://zakon.rada.gov.ua/laws/show/z1142-11) “On the temporary prohibition of the special use of the cetaceans of the Black and Azov Seas” prohibits their removal from the natural habitat) for any purpose, except for the collection of remains of fallen dolphins for research purposes.
The Animal Law of Ukraine establishes the basic requirements and principles, which are mandatory in the course of any activity that may affect the habitat of wild animals and the state of the animal world, in particular, these are preserving the conditions of species and population the diversity of the animal world in a state of natural will; inadmissibility of degradation of habitat, migration routes and breeding conditions of wild animals; preservation of the integrity of natural groups of wild animals, etc.
Moreover, the cetaceans that are listed in the Red List of the International Union for Conservation of Nature, Black Sea Red Data Book, are protected by the Bern Convention on the Conservation of Wild Flora and Fauna and the Natural Convention and the Bonn Convention on the Conservation of Migratory Species of Wild Animals, the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS).
According to the ACCOBAMS Agreement on the Conservation of the Cetaceans of the Black Sea, the Mediterranean Sea and the Contiguous Atlantic Ocean, all cetaceans of the Black Sea are species in need of protection in Ukraine. According to this international agreement, it is prohibited to remove cetaceans from the environment of the Black and Azov seas for subsequent maintenance in captivity.
Despite the norms of legal protection, in practice, there are problems with ensuring the implementation and enforcement of the above requirements and rules. Thus, although the removal of cetaceans from the natural environment is officially prohibited, there are cases of illegal catching to transfer them to dolphinariums and oceanariums. In addition, cetaceans suffer from the effects of industrial and anthropogenic pollution and die accidentally in fishing nets.
In view of the existing problems with the decline of cetaceans, in 2019 specialists of International charitable organization “Environment-People-Law” together with the public organization “BioEcoLinks” and experts from the Institute of Zoology I.I. Schmalhausen of the NAS of Ukraine and the Ukrainian Center for Marine Ecology held seminars in Kherson and Odessa on the conservation of the cetaceans of the Black and Azov Seas. The seminars were attended by scientists, students, environmental officials, representatives of local authorities, professional fishing associations, maritime carriers.
During the meetings, there were considered the problems that affect health and reproduction of cetaceans in the Black and Azov seas, including water pollution, artificial regulation of the Dnieper runoff through the functioning of the reservoir cascade, settlement of introduced species and destruction of ecosystems of the Black and Azov seas (mnemiopsis, rapana), violation of the set limits for the use of three-wall trammel net, poaching, military equipment testing and military training.
Other issues that were also addressed are:
– creation of new marine protected areas,
– modification of fishing and shipping regimes and rules,
– informing relevant state bodies about by-catches of cetaceans;
– marking of fishing gears to identify these gears and prevent cetaceans from entering the nets that are at sea and are abandoned;
– Amendments to Article 90 of the Code of Administrative Offenses and Article.249 of the Criminal Code: by-catches of dolphins and other objects of the Red Book, notified to the relevant control authorities, shall not be considered a violation of fisheries rules (illegal fishing, violation of requirements for the protection of species of animals and plants if a dead animal is transferred to a specialized scientific institution for scientific research.
Based on results of the meetings and analysis of cetacean conservation issues, proposals were made to the Ministry of Energy and the Environment of Ukraine to amend the fisheries regimes. These include the following suggestions:
Black Sea turbot fish and rays must be accompanied by a scientific observer. Scientific support and observations are required for all fisheries where there is a high risk of accidental by-catch of cetaceans, to respond promptly to such cases and to release live animals.
Allow experimental mounting on nets of acoustic instruments to deter cetaceans. Installation on acoustic mesh of cetacean deterrents is a must for EU countries. Their introduction into Ukrainian practice requires additional research and justification, so it is advisable to establish them experimentally within the framework of scientific and practical work.
Restrictions on the use of frames and three-wall trammel net in the extraction of herring and mullet reduce the likelihood of accidental by-catch of cetaceans. It is proposed to introduce for the herring in the Dniester estuary the same rules that are already in place at the mouth of the Danube. For the mullet fishing at the mouth of the Danube it is proposed to introduce the same tools that are used in other areas.
Catching invasive species such as rapana and silverfish contributes to the restoration of natural marine and estuarine ecosystems and is an important biotechnological measure. In addition, catching rapana can effectively replace fishing for other species of fish, which is dangerous for cetacean fishing gear. Therefore, rapana fishing should be stimulated by abolishing limits and restrictions on it. It is also proposed not to limit the by-catches of silverfish, but also to increase the maximum number of authorized dredges of Khizhnyak to a level that is consistent with the estimates of experts in the scientific basis of fisheries.
The number of nets used for fishing the hull in the Black Sea area west of the meridian 32°13’E.e., should be limited to 280 units. The length of the nets should not exceed 100 m. It is forbidden to connect such nets with each other. The use of pores and frames in nets is prohibited. Redlip mullet fishing should be accompanied by a scientific observer. Restricting the use of frames and cuts significantly reduces the likelihood of accidental by-catches of cetaceans. Scientific support and observations are necessary for all fisheries where there is a high risk of accidental by-catch of cetaceans to respond promptly to such cases and to release live animals.
The cetacean by-catch should be reported to the National Red Data Commission and the Ukrainian Marine Ecology Science Center. All species of cetaceans are listed in the Red Data Book of Ukraine. Therefore, catch records and information on the status of these species are issues of concern to the National Red Book Commission. This information should also be submitted to the Ministry of Energy’s main scientific institution responsible for environmental monitoring of the Black Sea, Ukrainian Scientific Center of Ecology of the Sea.
Dead cetaceans if found at sea or on land, must be provided free of charge for scientific research. Detected dead cetaceans are an important source of scientific information on the causes of death, life expectancy, diseases, and other data required for conservation measures, and should therefore be provided to scientists at no charge, in accordance with the applicable law.
Katheryna Polyanska, environmentalist ICO “Environment-People-Law” email@example.com
Pavel Goldin, Leading Researcher, Institute of Zoology, NAS of Ukraine firstname.lastname@example.org
Olga Melen-Zabramna, Head of Legal Department ICO “Environment-People-Law”, email@example.com
Natalia Kuts, Counsel ICO “Environment-People-Law” firstname.lastname@example.org
Karina Vishnyakova, researcher Ukrainian Scientific Center of Ecology of the Sea, the head of NGO “BioEkoLInks”, email@example.com
The study was supported by the Goldman Foundation.