The Atlantic white-sided dolphin (Lagenorhynchus acutus) is endemic to the North Atlantic where it lives in cold-temperate and sup-polar waters. It is not only one of the most heavily exploited cetacean species in the North Atlantic, it is also one of the most poorly understood, according to Susannah Calderan, a Scottish Association for Marine Science (SAMS) fellow and marine mammal expert. She explains: “In common with most small cetaceans, Atlantic white-sided dolphins are subject to a range of anthropogenic impacts including fisheries bycatch, accumulation of contaminants, underwater noise, and prey depletion. They are also thought to be particularly vulnerable to climate change.”

Currently classified as a species of Least Concern by the IUCN Red List of Threatened Species, researchers argue that this is due to insufficient research into the species. As these dolphins tend to primarily inhabit offshore areas that are out of sight of humans, impacts on the species are not well-documented. Furthermore, the species is so poorly understood in science that there are no accurate estimates on population size.

“The primary conservation concern is the drive hunt for Atlantic white-sided dolphins in the Faroe Islands. Between 1992 to 2021, 7603 Atlantic white-sided dolphins were caught and killed. In 2021, 1428 were killed in a single drive hunt,” says Calderan who recently compiled a report on the species that concluded there were no reliable population estimates available for the species, leaving them potentially vulnerable. Because Atlantic white sided dolphins are primarily an offshore species, they don’t fall under the various protections of individual countries – another reason no major research studies have been undertaken.

Calderan explains: “For Atlantic white sided dolphins it can be a case of ‘out of sight, out of mind’. It is more straightforward to study bottlenose dolphins because they are a coastal species; we have more of an idea where they are going to be. White sided dolphins are usually on the continental shelf or further out in the ocean. When we do find them, they don’t often ‘play’ with the boats and, because of their speed, are very hard to photograph. We have recordings of white-sided dolphins – they have an unusual whistle that sounds like a space alien – but no-one has documented the acoustic repertoire in detail before.”