A scientist studying orca interactions with small sailing yachts off the Iberian Peninsula believes their behaviour will stop once the marine mammals mature
Orca interactions with small boats off the coasts of Spain and Portugal are expected to stop as the marine mammals mature, according to one of the marine scientists studying the cetaceans’ behaviour.
Alfredo Lopez says the orca are displaying learnt behaviour but ‘it is a behaviour that should tend to become extinct as orcas assume different roles than they currently do, given that most of them are juveniles.’
According to the Center for Whale Research, male orcas reach sexual maturity at around 25 years of age; females attain sexual maturity in their early teens.
Lopez is part of Groupo Trabajo Orca Atlantica (GTOA), a group of Portuguese and Spanish marine scientists who have been studying the orca interactions since they began in 2020.
He said there are at least 16 orcas belonging to various groups of the same subpopulation which are interacting with boats, many of them young, and it was ‘unlikely’ that their behaviour could spread to other groups of orca, although not ‘impossible’.
The reasons for the orcas’ interest in small boats is still unknown, although Lopez believes it is ‘self-induced behaviour’: either the mammals have suddenly become interested in yachts, or it is ‘ a response to an aversive situation experienced in the presence of a sailboat’.
Since 2020, over 350 boats have suffered an interaction with this subpopulation of orca while sailing along the Iberian Peninsula, with around 70% being damaged; mostly the cetaceans bump or ram the hull and target the rudder.
In 2022, almost 70% of reported interactions resulted in damage and 24% resulted in the boat’s steering being disabled and requiring a tow from the emergency services to port.
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On 1 November, a second yacht was sunk after an orca damaged the boat’s rudder which resulted in a hole in the stern.
The four crew of the Beneteau Oceanis 393, Smousse managed to abandon ship for their liferaft, 14 miles west of the port of Viana de Castle, Portugal. They were eventually rescued by the crew of a passing Swedish boat.
Lopez said there is ‘no single or definitive solution’ for mitigating against an orca interaction with boats, although if sea conditions and location allows, stopping the vessel or reversing slowly may deter the mammals, reducing the interaction intensity.
The use of Anti Depredation Devices (ADD), known as pingers, and underwater firecrackers to deter orcas approaching boats is illegal in Spanish waters, due to the impact they have on the orca’s hearing and their ability to hunt and communicate.
Firecrackers have been used by organisations like the National Oceanic and Atmospheric Administration (NOAA) in the US to prevent orca and other marine mammals from swimming into oil spills.
However, these are detonated well away from the animals to prevent physical damage to them.
The largest member of the dolphin family, Orca are also a protected species, with the sub-group of orca in the Strait of Gibraltar declared critically endangered by the International Union for Conservation of Nature).
The Spanish Government has asked the Spanish technology centre, CIRCE to undertake an orca tagging project, but it is not known whether this will enable real time understanding of the location of orcas.
The Cruising Association (CA) is now working with GTOA to gather data on all orca interactions, as well as safe “uneventful passages” through the worst affected areas of the Iberian Peninsula.
It is hoped the information will help sailors with passage planning through the area and in publishing the data alongside skippers’ comments it is hoped that effective mitigation measures can be found.
Paul Lingard is a member of the CA Orca Project Group.
He said that while it was too early to draw any definitive conclusions, the data may suggest that boats with black antifouling appear to be more likely to suffer an interaction.
The CA data confirms suspicions aired by sailors on social media that staying in shallower water, where conditions allow, reduces the risk of an interaction.
However, the data suggests that the perceived wisdom of turning off the autopilot and depth sounder may not be effective.
Lingard said more data was needed and encouraged all skippers sailing the Iberian Peninsula to submit reports, whether they had an orca interaction or not.
The CA will also continue to lobby the Spanish and Portuguese authorities, and work with sailing organisations in the affected countries to try and find a solution.