The Hellenic Trench is core habitat for the eastern Mediterranean sperm whale sub-population, which is believed to number no more than two to three hundred individuals. The Mediterranean sperm whale population is listed as “Endangered” by the IUCN and is at risk mainly from driftnet entanglement and ship strikes. Major shipping routes running on or very close to the 1000 m depth contour along the Hellenic Trench are causing an unsustainable number of ship-strikes with sperm whales.
This study combined ship-strike information, together with whale sighting and density data and information on the vessel traffic in the area, to estimate the risk of whale/ship interaction.
According to this information, this study considered routing options that would most effectively reduce collision risk for sperm whales while minimising the inconvenience for the shipping industry. Among all possible options, only those that also provide a net improvement in overall marine safety were considered.
The authors highlight that the small routing changes proposed in the region would make a significant contribution to the overall conservation status of the Eastern Mediterranean sperm whale population and Natura2000 sites in the area. Moreover, it is stated that there would also be additional environmental benefits if shipping avoided the suggested areas, including reduced impacts from shipping noise and reduced risk of any oil spills reaching the coasts, which include sensitive Natura2000 areas as well as important touristic destinations in Greece.
Frantzis et al. (2019) Shipping routes through core habitat of endangered sperm whales along the Hellenic Trench, Greece: Can we reduce collision risks? PlOS ONE 14:e0212016.