Maritime activity uses huge ships that transport more than 80% of traded goods across the oceans. These large vessels put thousands of whales at risk each year, resulting in injuries or deaths when they are struck by these ships, increasing their mortality rate.
These collisions are the main cause of cetacean deaths. Although it is difficult to know the exact numbers of victims, it is known that the risk posed by these ship-whale collisions affects all cetacean species worldwide.
Commercial routes in the Chilean Pacific
The greater the overlap between the areas inhabited by whales and commercial routes, the higher the risk of these events occurring.
Whales are the largest known animals in the world, reaching between 25 and 31 meters in length and weighing between 100 and 135 tons. Despite their enormous size, ship collisions are one of their main threats. In many cases, the injuries they suffer are fatal.
Recent studies on the impact of whale collisions in Chile
According to the Cetacean Conservation Center of Chile, there are around 87 species of cetaceans in the world and approximately half of them have been recorded in Chilean waters. Whales arrive during the southern hemisphere summer to feed.
Although these species are threatened with extinction, the causes of their deaths have been poorly studied on the Pacific coasts of South America. Most research has focused on Australia and New Zealand.
To understand the causes of whale mortality in this region, over 20 marine mammal specialists gathered to conduct a study, recently published in the Marine Policy journal.
The study concluded that, in the last five decades, vessel collisions have been the main cause of death and injuries in the cetaceans swimming off the coasts of Chile.
Between January 1972 and September 2023, 226 large whale strandings were recorded, of which 141 had an unknown cause of death and 63 were associated with ship collisions.
Proposals to mitigate the impact
Historically, the annual average was five deaths, mainly due to vessel collisions. However, in 2022, three deaths due to this cause occurred in just one week. This worrisome scenario led to the creation of a team of 22 experts to investigate and propose solutions.
Researchers collected data on whale strandings provided by the National Fisheries and Aquaculture Service (SERNAPESCA), universities, NGOs, and expert groups. This data was cross-referenced with databases on maritime traffic patterns in each region and compared with figures from other countries.
The results obtained alarmed the scientific community, as vessel collisions are by far the main cause of non-natural deaths in whales in Chile. They are followed by entanglements (7%) and natural predation (3%).
The figures presented in the study represent a minimum estimate of cetacean mortality, since in many cases the corpses sink or are swept out to sea, never reaching the beaches.
Critical areas for whale mortality
One of the study’s conclusions is that the fin whale (Balaenoptera physalus) is the most affected species by collisions, representing 37% of recorded deaths. This species has been classified as Critically Endangered by the Chilean Ministry of the Environment and as Vulnerable by the International Union for Conservation of Nature (IUCN).
Collisions are concentrated in the country’s port areas. Susannah Buchan, from the Center for Oceanographic Research of the Southeastern Pacific (COPAS Coastal), explains that this is because whale-important areas, such as feeding and transit locations, overlap with port areas and maritime traffic routes.
So far in 2025, two cetaceans have died due to ship collisions in Chile: a humpback whale in Nehuentúe and a sperm whale in Tocopilla. Researchers suggest vessels reduce speed along the entire Chilean coast and particularly in port areas to no more than 10 knots (18.52 km/h). Furthermore, they propose that the regions of Antofagasta, Valparaíso, Biobío, Los Lagos, and Magallanes be designated as Critical High-Risk Areas, where speed restrictions and redesign of maritime routes are implemented in consultation with local stakeholders.
Preliminary voluntary agreements could serve as a basis for future mandatory national regulations on maritime traffic. It is also necessary to strengthen and properly fund SERNAPESCA’s marine mammal stranding unit, establish cooperation agreements with research institutions, and create a national task force to address collisions, coordinated by the General Directorate of Maritime Territory and Merchant Marine (DIRECTEMAR).
Cover photo: @Panthalassa.
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