INVESTIGATING PELAGIC FISH LARVAL DISPERSAL AND ECOLOGIC CONNECTIVITY IN THE BLACK SEA USING LAGRANGIAN DRIFTER MODELING

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2019-9-24

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Çağdaş, Bulut

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In order to understand fish population dynamics, understanding the physical interaction of the current systems with pelagic fish larvae is necessary. Using a Black Sea circulation model output to undertake Lagrangian drifter studies embedded with a Lagrangian Flow Network the connectivity metrics; onshore transport, offshore transport, local retention and self recruitment are calculated for six different commercially important fish species in the Black Sea: anchovy (Engraulis encrasicolus ponticus), sprat (Sprattus sprattus), red mullet (Mullus barbatus), horse mackerel (Trachurus mediterraneus ponticus), bluefish (Pomatomus saltatrix) and turbot (Scophthalmus maeoticus). Simulations are taking interannual and seasonal variations as well as pelagic larval durations and spawning times of the target fish species into account. Results show that offshore transport is inversely proportional to local retention and self recruitment and that longer pelagic larval duration times effected local retention negatively. Winter season shows the lowest retention values and highest offshore transport followed closely by autumn while spring shows the highest local retention followed closely by summer with both seasons exhibiting the lowest offshore transport values. The northern part of the north western shelf, the south eastern coast of Turkey and the entrance of the Azov Sea show retention in all seasons. The eastern and western gyres show potential retention sites for spring and summer while the remaining areas were susceptible to strong transport facilitated by the rim current that is dependent on seasonal and interannual variations of the Black Sea circulation.

Subject Keywords

Black Sea, Pelagic Larval Duration, Local Retention, Offshore Transport

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https://hdl.handle.net/11511/95083

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Graduate School of Marine Sciences, Thesis

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Citation Formats

B. Çağdaş, “INVESTIGATING PELAGIC FISH LARVAL DISPERSAL AND ECOLOGIC CONNECTIVITY IN THE BLACK SEA USING LAGRANGIAN DRIFTER MODELING,” M.S. - Master of Science, Middle East Technical University, 2019.