A comparative analysis of maritime traffic data from 2023 and 2024 has revealed that voluntary speed reduction measures for vessels in the northwestern Mediterranean are failing to protect endangered whale species such as fin whales and sperm whales.
Conducted by Quiet Oceans for OceanCare and its partner organisations, the study shows that more than 80% of merchant vessel travel in the region occurred at speeds exceeding 10 knots levels proven to be fatal in the event of a collision. Environmental groups are now urging for mandatory speed limits to safeguard marine life within the Cetacean Migration Corridor, a key whale habitat recognised by both Spain and the United Nations.
Persistent Speed Risks in the Whale Migration Corridor
Despite being designated as a Particularly Sensitive Sea Area (PSSA) by the International Maritime Organization (IMO) and a Marine Protected Area (MPA) by Spain, ships continue to travel at dangerously high speeds.
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Over 48 million kilometres were sailed through the PSSA in 2023–2024, with 57% of the distance covered at speeds above 10 knots.
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Ferries, the fastest vessels in the region, travelled more than 11 million kilometres in 2024, with over 90% of this distance at speeds above 10 knots and nearly 30% exceeding 20 knots.
These figures confirm that voluntary speed limits between 10–13 knots, introduced by the IMO, have not been adopted widely. OceanCare’s Carlos Bravo emphasised that only mandatory measures could ensure compliance and meaningful protection for marine mammals.
Environmental and Policy Implications
Experts argue that reducing vessel speeds would deliver multiple environmental benefits beyond whale protection including cutting underwater noise, CO₂ emissions, and other pollutants such as SOx, NOx, and black carbon.
However, despite scientific consensus, regulatory action has been slow.
The Spanish Ministry for Ecological Transition and Demographic Challenge (MITECO), in partnership with the Ministry of Transport and Sustainable Mobility (MITMS), is developing a management plan for the MPA, expected by June 2026 several years behind schedule.
A coalition of environmental organisations including WWF, Greenpeace, Oceana, and ClientEarth has called for:
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A general 10-knot speed limit for all vessels, including recreational boats.
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A Traffic Separation Scheme (TSS) to channel ships through safer routes.
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Mandatory speed reductions for ferries operating on fixed public service routes.
The coalition also delivered a petition signed by 60 experts to Vice-President Sara Aagesen, who reaffirmed the government’s commitment to enforcing vessel speed reductions.
The findings underscore a pressing need for stronger maritime regulations in the northwestern Mediterranean, where ship strikes remain the leading cause of whale deaths. While voluntary efforts have failed to reduce vessel speeds, making speed limits mandatory could become a turning point for marine conservation.
By enforcing scientifically guided speed reductions, Spain and the IMO have the opportunity to make the Cetacean Migration Corridor a model for sustainable coexistence between marine biodiversity and maritime commerce ensuring that endangered whales continue to thrive for generations to come.
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Source: Ocean Care
