12.09.2020 – Bittersweet alliances

Our work is truly rewarding. Not only do we have the absolute luxury of enjoying days out on the beautiful Atlantic, we also get to spend that valuable time with our guests and share all our knowledge with them. This morning the Atlantic offered us spectacular sightings with a large group of Atlantic spotted dolphins (Stenella frontalis), some peaceful Short-finned pilot whales (Globicephala macrorhynchus) and a curious pod of Bottlenose dolphins (Tursiops truncatus). The sighting of the Bottlenose dolphins aboard the Ribeira Brava happened as they were swimming alongside the pilot whales, giving off dark excrements that seemed to contain ink as they drifted by us. Studies looking into these interactions suggest that the Bottlenose are the ones seeking the company of the pilot whales and that they probably do so to gain hunting advantages for squid.

While such encounters are largely peaceful and the possible reasons for them merely based on theories, the motivation to gain hunting advantages for squid may have more sinister ecological implications. Apart from plastic pollution and climate change, overfishing has had dreadful effects on our oceans. Over-harvesting certain fish stocks has caused massive declines in their populations, leaving top predators such as toothed whales to resort to faster-growing prey such as squid. Squid proliferate in the deep and do so much quicker than most fish species and such decimations in fish populations gives these intelligent cephalopods ample room to multiply. While squid are the targeted prey of pilot whales and represent a hydrating prey for the Bottlenose as well as other dolphins, they are harder to catch and not as nutritious for the animals as most schooling fish of commercial interest, such as Atlantic mackerel (Scomber scombrus).

Are the Bottlenose merely interacting with the pilot whales to ease their deep dives for squid out of desperation? It’s hard to say since the changes our exploitation has caused send extremely complex shock waves through the food web. What’s for sure is that cetaceans are able to adapt but we must make it our duty to not force them to do so.

Since yesterday, our team can proudly call themselves partners of the World Cetacean Alliance (WCA), a large organisation and network dedicated to protecting cetaceans worldwide and promoting a sustainable attitude towards them. The organisation also aims to set up whale sanctuaries worldwide, protected areas where marine life can recover and where top-predators face less struggles in pursuing their natural prey.

If we see ourselves as allies of cetaceans we must begin to behave that way. The animals aren’t only important ambassadors for the protection of our oceans, they are their shepherds.

By Paula Thake

Sightings of the day

Ribeira Brava

10:00 Atlantic spotted dolphins, Bottlenose dolphins, Short-finned pilot whales

Stenella

10:00 Atlantic spotted dolphins, Short-finned pilot whales