| Abstract |
Mediterranean
Sea fish stocks are experiencing dramatic changes due to the invasion of
Lessepsian species. While stocks of many indigenous species are decreasing
due to overfishing and habitat destruction, assessments of benthic fisheries
found that the percentages of Lessepsian fishes in the total catch have
increased significantly since 1980’s. Threadfin bream (Nemipterus randalli)
is one of these Lessepsian species, that, although first detected in 2005 in
the Mediterranean, has already established important commercial fisheries
along the Turkish Eastern Mediterranean coast and in Israel.
The motivation of this study is to investigate how the distribution of
Threadfin bream is related to the coastal bathymetry, bottom substrate and
physical oceanographic conditions in the Mediterranean Sea, which create
suitable habitats. In addition, investigating how these habitats may change
in the future due to changes in physical oceanographic condition caused by
climate variability and an increasing trend in water temperatures is of great
importance.
This study will conduct trawl surveys onboard Research Vessel Lamas of the
Institute of Marine Sciences, Middle East Technical University at the Turkish
coast of the Eastern Mediterranean. There will be monthly surveys in Mersin
Bay as well as three basin-wide surveys in the Cilician Basin, from the
Syrian border to Anamur, to assess the current distribution and biomass of
Nemipterus randalli. In addition, research cruises on R/V Lamas investigating
seabed sediment substrate will be undertaken. The findings of these surveys,
together with existing data from previous trawl surveys available at the
Institute of Marine Sciences, will be incorporated into a sophistical
biophysical model of Nemipterus randalli that will be developed in this
study. Therefore, on the basis of computer modelling and field work, this
project aims to estimate larval dispersal patterns, settling locations of
Nemipterus randalli, and regional invasion pressure in different regions
along the Turkish coast of the Mediterranean Sea.
Since Threadfin bream is a valuable species for the Turkish fishing
industry the overarching aim of the project will be to detect important
fishing grounds of Threadfin bream today and forecast possible new fishing
grounds. |
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