Unit:
Department of PhysicsLibrary of the School of Science
Author:
Gkanasos Athanasios
Dissertation committee:
Sofianos Sarantis (Supervisor), Associate Professor, National and Kapodistrian University of Athens Department of Physics
Triantafyllou George, Research Director, Hellenic Centre for Marine Research (HCMR), Institute of Oceanography
Petihakis George, Research Director, Hellenic Centre for Marine Research (HCMR), Institute of Oceanography
Somarakis Stylianos, Research Director, Hellenic Centre for Marine Research (HCMR), Institute of Marine Biological Resources
Flocas Helena, Professor, National and Kapodistrian University of Athens Department of Physics
Tombrou-Tzella Maria, Professor, National and Kapodistrian University of Athens Department of Physics
Raitsos Dionysios E., Assistant Professor, National and Kapodistrian University of Athens Department of Biology
Original Title:
Study of the climatic changes in the North Aegean Sea and their effects on the ecosystem dynamics
Translated title:
Study of the climatic changes in the North Aegean Sea and their effects on the ecosystem dynamics
Summary:
Climate change is more than ever observed and is affecting the marine ecosystem in global scale. For the study of changing climate conditions, we focused in the North Aegean Sea and the most common species of small pelagic fish, anchovy and sardine. We studied the effects on species from changes in temperature, salinity, Black Sea Water input and nutrients load from the surrounding rivers. For the needs of the study, a multispecies anchovy and sardine, full-life-cycle model was developed for the North Aegean Sea and was two-way coupled to the hydrodynamic/biogeochemical model. The initial one-dimensional version of the model successfully simulated both species growth, biomasses and spawning periods. A clear dependence between species exploitation and zooplanktonic concentration was derived.
The next step in the model development yielded a three dimensional version. The species main attributes and the spatial distribution of biomasses, was once again in agreement with data. Additional simulations showed that locally, species compete for resources. Sensitivity experiments presented a negative reaction of both species to a temperature increase, especially that of anchovy. Simulations using IPCC climatic scenarios showed that a future temperature increase will result to an ecosystem degradation through a reduction in planktonic concentrations, negatively affecting anchovy and resulting to a prevalence of sardine. Last, variations of river nutrient inputs, as well as Black Sea Water inflow, also significantly downgrade species populations.
Main subject category:
Science
Keywords:
NORTH AEGEAN SEA, BIOENERGETICS MODEL, GENETIC ALGORITHM, CLIMATE CHANGE
Number of references:
155
