The spatial and temporal distribution of the shads in Black Sea marine zone of Danube Delta Biosphere Reserve
Journal Title: Scientific Annals of the Danube Delta Institute - Year 2014, Vol 20, Issue
Abstract
Three species of the shads (Alosa genus) are known to live in the north-western Black Sea including Pontic shad (Alosa immaculata - Bennett, 1835), Black Sea shad (Alosa maeotica - Grimm, 1901) and Azov shad (Alosa tanaica - Grimm, 1901). The paper presents actual occurrence and distribution of shad species in Black Sea, Natura 2000 site ROSCI0066 (Danube Delta - the marine zone). Fishing sampling was conducted in 2012, using fix gillnets during the night and trawl fishing throughout the day. Survey showed that in 2012 were present only two species of shads, respectively A. immaculata and A. tanaica. In the last 50 years, A. maeotica, that lives in Sea of Azov and occasionally reach Romanian coast, was not cited as present in Romanian marine water. The two species of shads are present in RSCI0066 all over the year. The space distribution increases from south-west to north-east and from deep sea of the 20 m isobaths to the shore, with a maximum aggregation close to the Danube River mouth. In time the presence of shads decrease from spring to autumn. The conservation status of shads appears to be in suitable condition but under the pressure of fishing and habitat loosing and degradation. Close fishing and area, sustainable fishing, monitoring and research is require for preserving shads from Black Sea - Danube river system area.
Authors and Affiliations
NĂVODARU Ion, MAXIMOV Valodea
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