The Canary Islands are a privileged area for cetacean watching worldwide, about twenty species reside or visit the archipelago every year and on the islands you can see 30% of the types of cetaceans that exist on the planet. However, these marine animals suffer the consequences of sharing the oceans with millions of tourists and 2.2 million residents, with trawling, noise and collisions due to the traffic of boats through their habitat.
Alicia Rodríguez Juncá is a predoctoral student at the University of La Laguna, and investigates the ecology of pelagic megafauna, that is, those large marine animals that inhabit deep waters, and how the relationships between these animals and human activities are. This biologist, expert in Biodiversity and Conservation, has coordinated several observation campaigns of pilot whales and beaked whales and also directs the Interspecies Project, an investigation on the interactions between artisanal fishing and cetaceans, elasmobranchs, turtles and birds.
In this Interspecies investigation, from 2023, Rodríguez and a group of experts pointed out that the accidental capture in the archipelago was "high" and that the techniques to release the animals could be "causing injuries". In this analysis they verified that sharks and rays were more affected by accidental catches than cetaceans and that this fishing by mistake was more frequent in Lanzarote and Fuerteventura.
In the case of cetaceans, this researcher points out that the greatest risks they face are caused by humans. "Depending on the group we are talking about, they could be more impacted by some activities or others," she says during an interview with La Voz. For example, in the case of the sperm whale (Physeter macrocephalus Linnaeus), an endangered species in the islands, the main cause of risk to its life is collisions with boats.
Last week two sperm whales appeared dead on the coast of Tenerife, with signs of having been run over by large boats. A study from the University of La Laguna, published in the journal Plos One, warned in 2016 that sperm whales killed by ships could exceed "the natural growth capacity" of the species. Nine years later, researchers from the Canary Islands Oceanographic Center (IEO/CSIC) and the University of La Laguna (ULL) stated that collisions against sperm whales are "leading" the species to "local extinction".
Along with collisions, Alicia Rodríguez explains that noise "is a very important impact that must begin to be regulated." Along these lines, researchers from various countries and also in the Canary Islands have been monitoring how excessive noise in the sea, caused by recreational boats, cetacean watching boats, sports boats and high-speed boats, generate stress in resident populations of tropical pilot whales (Globicephala macrorhynchus). "The noise of the boats can alter the behavior of this species, reducing the resting rate of mothers and lactation of the young," the University of La Laguna said in a statement in 2022.
"In very touristy areas, the number of recreational boats that we have here in the Canary Islands are producing a lot of noise and that can be seen in the stress they generate to the animals," says the expert in Conservation, who also exposes the stress generated by the approach of cetacean watching boats.
Currently, the public university is working on the detection of areas sensitive to collisions, crossing data of sperm whale populations with maritime traffic figures. "First we need to know the cetacean populations well, because it is not the same where sperm whales are distributed as where beaked whales are distributed and all species may have this risk of collision." At the same time, the University of Las Palmas is studying stranding data to see where the collisions may have occurred.
Thus, "any type of boat can have a collision, but a larger boat will have more impact." In this sense, she points out the difficulties in being able to record all the collisions that occur in the Canary Islands, since when animals are run over in the high seas it is likely that their body will not end up stranding on the coast. "The number of collisions we believe is an underestimation, there are really more collisions than are recorded in the strandings and this falls within the little information we have," she adds.
Along with shocks and noise, the Canary marine species face pollution that affects the entire planet. "Garbage that can be very large, such as drifting nets or plastics that can trap animals, but also microplastics cause impacts on marine fauna and can end up in our body," she adds.
Faced with this reality "that has been going on for a long time without measures being taken to avoid it", Rodríguez Juncá indicates the need to protect ecosystems, since the loss of a link could trigger an imbalance in the entire food chain.
In this way, she proposes reducing the speed of boats and jet skis, but also of boats that transport passengers and controlling the transit of boats in certain areas. "The fact of reducing the speed will make it easier to detect these animals and that they have more time to react. In addition, it would not only be the collisions, but we would also be reducing the noise that is harmful to these animals."
The islands have already tested thermal cameras to see if cetaceans can be detected when sailing at high speed, while considering cutting-edge technology. "That someone is watching in case there may be animals, makes the difference," she concludes.