MODELING THE IMPACT OF CLIMATE VARIABILITY ON ANCHOVY OVERWINTERING MIGRATION IN THE BLACK SEA

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2016-10-21

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Güraslan, Ceren

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Black Sea anchovy (Engraulis encrasicolus ponticus) undertake extensive (~1000km long) overwintering migration in autumn from northern spawning grounds to the overwintering areas located at the south-eastern coasts of the Black Sea. When arriving at the Anatolian coast, they support important fisheries in Turkey. Black Sea anchovy is known to experience stock variability quite frequently including stock collapses, which are believed to be closely linked with environmental conditions. Therefore, it is of importance to understand the mechanisms that set the scene for a successful migration and explore routes feasible for migration. To investigate anchovy overwintering migration, a fish behavior model embedded into a 2D Lagrangian particle tracking model is used. Particles are released into the surface circulation field calculated from AVISO sea level anomaly data. Model simulations are performed during years of very different physical conditions from 2001 to 2003. The results show that while advection by currents influences transport pathways, temperature used as a guide for migration is of more importance for high migration success. Simulations reveal highly variable migration pathways driven by the onset and course of winter cooling processes, cross-shelf transport, and variability in eddy formation and persistence.

Subject Keywords

Black Sea, Lagrangian particle tracking model, anchovy, migration behavior, climate variability

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https://hdl.handle.net/11511/95100

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Graduate School of Marine Sciences, Thesis

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Citation Formats

C. Güraslan, “MODELING THE IMPACT OF CLIMATE VARIABILITY ON ANCHOVY OVERWINTERING MIGRATION IN THE BLACK SEA,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.