Advances in Marine Ecosystem Modelling Research (AMEMR) International Symposium , Plymouth, England, 12 - 15 July 2021
The Mediterranean Sea is home to numerous invasive species that migrated through the Suez Canal, some of which have already established thriving populations. These Lessepsian species account for 2/3 of all alien species recorded in the sea today and impact native species and the equilibrium of the marine ecosystem. One example is Threadfin bream (Nemipterus randalli), a benthic fish with a pelagic larval stage, which was first detected in 2005 off the coast of Israel and has been a particular successful invader. Several important commercial fisheries of N. randalli along the Eastern Mediterranean coast were established within only 5 years of its first record. Interestingly, this fish is well established in the Eastern Mediterranean Sea but not yet in the Aegean Sea. This study focuses on explaining the invasion success of this particular species, reproduce its pathway through the Eastern Mediterranean and predict possible future invasion dynamics of N. randalli depending on identifying suitable habitats and pathways to reach them. This can be done with Lagrangian drifter simulations or as done in this study with a cellular automaton (CA) modeling technique, that integrates environmental conditions such as surface current speed and direction, temperature, salinity, water depth and bottom substrate in 4 x 4 km model cells. Here we present a CA model that is able to reproduce the invasion path so far, even though in the current version only physical parameters are taken into account. First results show that both water depth and bottom substrate is a strong limitation to the successful invasion of the Aegean Sea. Benefits and caveats of using a cellular automaton are discussed in this study.