black sea red data book - Department of Biology

from Cape Lookout to Labrador. Threats: pollution of the Bosphorus and presence of
predators such as tuna, dolphins and shark.
Biology. The species spends winter in the Marmara Sea, in front of the Bosphorus;
entering the Black Sea in spring, it moves northward, reaching the Romanian coasts in
April-May when water temperature is 8 °C. In October-November it moves south and
in December it leaves the Black Sea. Spawning takes place in late winter - early
spring in the Marmara and Aegean Seas. Individuals staying in the Black Sea in
winter do not reproduce, because juveniles need to move to great depths, which are
predator-free. Feeds chiefly on pelagic invertebrates (Acartia, amphipods, mysids,
pilchard, sprat and eel).
Population trends. The stocks considerably decreased due to adverse conditions for
feeding and breeding. In Romania separate statistics were kept for this species until
after the 1960s, when it disappeared as a commercial species. On the Turkish coast,
the catches recorded by FAO were 39 t (1989), 561 (1990), and 780 t (1991).
Threats. Overfishing, pollution, predation (bonito, shark and dolphins).
Conservation measures taken. In the last 25 years, no gill nets have been allowed
for catching mackerel.
Conservation measures proposed. Ensure migration into the Black Sea by
mitigation of eutrophication/pollution.
References
FAO, 1973. Species identification sheets for fishery purposes. Mediterranean and
Black Sea, fishing area 37. Rome.
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