Collision Risk: Slowing Down to Protect Endangered Whales!

A High-Risk Area for Collisions with Endangered Whales

Following the adoption of a Resolution at the 7^th Meeting of the Parties to the Agreement for the Conservation of Cetaceans of the Black Sea, the Mediterranean and contiguous Atlantic area (ACCOBAMS) in 2019, France, Italy, Monaco and Spain jointly proposed the establishment of this PSSA by the IMO, which was finally adopted in July 2023 and came into force on January 1^st 2024.

The main measure identified to reduce the risk of such collisions in this region with fin whales and sperm whales, both classified as endangered, is to reduce vessel speed. As the habitat use of the Northwestern Mediterranean Sea by the two species can hardly be predicted, routing measures aren’t suitable given the status of knowledge at current stage.

Why vessels need to slow down

A speed of 10 knots has been identified by scientific analysis to be the kind of threshold for vessel speed which, once exceeded, increase the risk of lethal collisions significantly. In the measures to be applied within the PSSA, the reduction of vessel speed to between 10 and 13 knots once a whale is observed has been identified. However, this measure is by voluntary nature, which makes its effectiveness very low.

On the one hand, it is widely accepted that spotting a whale is not easy. Even in the event that a whale is spotted in the vicinity from a vessel travelling at its usual average operational speed, it is in most cases virtually impossible to reduce speed to 10-13 knots in time to avoid collision with the whale. It is most often also too late to change course, should the skipper decide to do so. This kind of voluntary measure is also ineffective for whales that approach the surface but go unnoticed.

Vessel Speed Performance within the PSSA

To better understand the current vessel-speed performance of individual ships, as well as vessels of certain categories, OceanCare has commissioned Quiet Oceans, a French institution, to undertake an analysis for vessel traffic during the entire year 2023 for the entire region of the PSSA in the NW-Mediterranean Sea. This analysis allows to better understand the current practises, those vessels and vessel categories posing a risk to these whales and working closer with the shipping industry in identifying ways forward to reduce vessel speed to protect these ocean giants.

Merely 15% of the distance travelled by the 6 main merchant vessel categories would be considered as “safe speeds” for marine biodiversity in terms of collision risks. As the speed range increases, roll-on roll-off vessels are revealed as the type of ship that presents a significant increase in the distance travelled in the highest speed sections, being clearly the predominant one in the section speed of more than 20 knots.

Agreeing and imposing mandatory measures to reduce vessel speed is one of the six main asks towards governments around the world within OceanCare’s initiative “Because our Planet is Blue”. Such measure would reduce the ecological impact of shipping significantly by reducing GHG emissions, air pollutants, ocean noise as well as the risk to collide with endangered whales. Sign the petition here.

Additional Information

Infographs: Core findings of the vessel traffic analysis for the Northwestern Mediterranean Sea

Press Release: Data of vessel traffic analysis

Factsheet: Ships and whales: A fatal relationship?

Conference: Ship speed reduction to protect large whales in the Mediterranean Cetacean Migration Corridor