Modelling of possible tanker accident oil spills in the Istanbul Strait in order to demonstrate the dispersion and toxic effects of oil pollution

Countries located on the Black Sea coast perform most of their sea trade through the Istanbul Strait (IS). Approximately 50,000 ships pass through the IS each year, with crude oil tankers making up the majority. Thus, the aim of the study is to determine the acute toxic effect of oil pollution that may occur as a result of crude oil tanker accidents in the IS. By utilising data related to accidents that have occurred in the IS, locations of concentrated tanker accidents, or "hot spots," were determined by Kernel Density Analysis. Subsequently, the distribution of potential leaks following an oil tanker accident, within these hot spots, is modelled with GNOME software. Finally, acute toxicity caused by oil pollution in the marine ecosystem is determined by Aliivibrio fischeri luminescent bacteria toxicity test. In this research, 5 hot spots are identified, where the maximum calculated amount of oil that can reach the coastline after 72 h is 3096 metric tons. Similarly, oil pollution can affect a total coastline of 30-35 km. Furthermore, it was determined that after the oil was diluted in seawater, at a ratio of 1:200,000, the toxic effects decrease (EC₅₀ above 100 mg/L), yet the chronic effects may still continue. The results of this study may serve as a reference for coastal state authorities to develop emergency response plans. Having this valuable knowledge of where high-risk accidents are most concentrated, where the accidents occur intensely, which areas can be affected by the pollution, the duration of the pollution effects, and the distance between the areas, will help determine the number of intervention stations to be installed, their locations, and equipment to be installed to the stations.