Atlantic Mackerel
Scomber scombrus Linnaeus, 1758
Order Perciformes
Family Scombridae
Conservation status: in Bulgaria: Critically endangered CR [A1abc; E].
General distribution. The northern part of the Atlantic Ocean and the adjacent seas: the Black Sea, the Sea of Marmara and the Mediterranean Sea. Along the Atlantic coast of Europe – from the Canary Islands northward to the North Sea, the Baltic Sea, the Norwegian Sea and the Barents Sea; along the Atlantic coast of North America – from Cape Hatteras to Labrador.
Distribution and abundance in Bulgaria. In the past (until 1970), the Atlantic mackerel was one of the most valuable commercially Black Sea fish species in Bulgaria [1, 2, 3]. It overwintered in the Sea of Marmara, and in the spring, it entered the Black Sea and moved northward for feeding. When passing along the Bulgarian coast, it was caught in large quantities. In the autumn, on its way back to the Sea of Marmara, already well-fed, the species was again an object of commercial fishing. During the last 46 years, however, the entering of the species into the Black Sea stopped abruptly, and at present, single specimens are caught very rarely [4].
Habitats. It is found only in the open sea.
Biology. In the period February–May, the species overwinters and spawns in the Sea of Marmara at a depth of 50–70 m, water temperature of 14°C and salinity over 38‰. Sexual maturity is attained in the first year. The fecundity of females varies from 164 000 to 335 000 eggs. They spawn repeatedly. The eggs are pelagic. It has a mixed type of feeding. In the spring and autumn, it preys predominantly on fish – Mediterranean sand eel, anchovy, small horse mackerel, sprat and sand smelt, while in the summer, it feeds mostly on zooplankton [2, 5].
Similar species. In the Black Sea and the Sea of Marmara, another species belonging to the family Scombridae is found - the chub mackerel (Scomber japonicus). The Atlantic mackerel differs by the absence of a swim bladder and by having a white, unmarked belly.
Negative factors. Degradation of habitats, associated with the intensive traffic of sea vessels through the Bosphorus; water pollution; overfishing.
Conservation measures taken. The species was listed in the Red Data Book of Bulgaria (1985) and the Red Book of the Black Sea (1999).
Conservation measures needed. Introduction of a ban on Atlantic mackerel fishing in the Black Sea and implementation of a permanent monitoring of its population.
References. 1. Drensky, 1951; 2. Stojanov et al., 1963; 3. Konstantinov, 1964; 4. Karapetkova, Zivkov, 1995; 5. Svetovidov, 1964.
Authors: Yanaki Sivkov, Tihomir Stefanov, Teodora Trichkova
