Collaboration and precautionary measures needed to figure out why Iberian orcas attack vessels
In May, Spain’s maritime rescue service reported the sinking of a yacht after orcas rammed the hull and rudder of the boat in the latest in a series of such incidents around the Strait of Gibraltar.
Orcas, also known as killer whale; are the largest member of the marine dolphin or toothed cetacean family, Delphinidae.
Interactions between a small and critically endangered population of 35-40 Iberian orcas and vessels were first reported in the summer of 2020. These interactions have occurred persistently since then, mostly off the Iberian Peninsula, in the Gulf of Cádiz and the Strait of Gibraltar, but also as far north as France and as far south as Morocco.
Orca swimming alongside a fishing boat in the Strait of Gibraltar
More than 650 encounters have been recorded in which the orcas push or ram the rudders of the vessels, sometimes damaging and breaking them. Reports suggest seven vessels (five sail boats and two fishing boats) have sunk as a result since 2021, with the most recent incident occurring last month.
These interactions have involved 15 individually recognisable orcas, often seen in smaller groups. Most interactions occur during the day and with sailboats and have led to aggressive responses by some mariners. Concerns have been raised about the use of harmful measures, including the use of firecrackers, explosives or electrocution, employed by mariners to deter the whales. Such measures have been shown to be ineffective and are illegal.
Aggressive responses by mariners adds a new and important threat to this critically endangered Iberian orca population. In addition to the very low abundance, the population suffers high newborn mortality rates and a declining adult female survival rate. These factors are very concerning and have negative implications for the future of this small and vulnerable population.
(c) WeWhale for save-the-iberian-orca.org/
Orcas are smart. They demonstrate complex social behaviours, sophisticated and distinctive dialects and regional feeding specialisations that are maintained by cultural transmission, such as stranding to hunt basking seals off beaches in Peninsula Valdés, Argentina.
The reason for the behaviour towards boats in the north-east Atlantic is unknown. One theory is that the whales were previously preoccupied searching for prey when bluefin tuna, their main prey, were scarce; now that the tuna population has increased, the whales have more time for ‘playful’ behaviour and may be ramming the rudders for fun — juvenile whales are often involved.
Spanish and Portuguese authorities have responded to the interactions by undertaking a number of independent actions, such as increased monitoring, issuing navigational warnings when the whales are in the area and proposing mitigation measures, including a response protocol involving stopping the engine and turning off all equipment.
In response to the ongoing concerns and the serious nature of some of the incidents, the Spanish and Portuguese governments organised an international workshop to assess existing and review additional mitigation measures and to develop practical solutions, as well as research recommendations.
The workshop’s participants agreed that the most effective form of mitigation is to keep the whales and vessels apart, which involves providing real-time information about the presence of the whales and influencing mariner behaviour to avoid orca hotspots and move quickly several kilometres away when members of the population are encountered.
EIA agrees with the approach, although we urge a non-invasive approach to monitoring the endangered population — given the risks associated with satellite tagging and the availability of alternative monitoring methodologies, we believe tagging is inappropriate for this small endangered population.
(c) WeWhale for save-the-iberian-orca.org/
The Scientific Committee of the International Whaling Commission (IWC) discussed the workshop report at its meeting in Slovenia in April 2024, endorsing the primary recommendations and continued international efforts to resolve the issue. Clearly, collaborative research and effective management of human activities are required if this small and critically endangered orca population is to survive and recover.
Founder of WeWhale, Janek Andre, who runs the Save the Iberian Orca campaign with Sea Shepherd France, also emphasises the importance of collaborative efforts:
“The situation with the Iberian orcas is a complex interplay of animal behaviour and human activities,” he said. “These majestic animals have called the Strait of Gibraltar their home for over 3,000 years. To ensure the survival of this critically endangered population, it’s crucial that we adopt a multifaceted approach that includes robust and non-invasive monitoring, effective vessel management, and continued research into the orcas’ behaviour.
“Only through international cooperation and evidence-based strategies can we hope to mitigate these interactions and support the recovery of these remarkable beings.”
