27.01.2022 – Understanding interactions

Whale-watching is all about observing cetaceans in their natural habitat while disturbing them as little as we can. The idea is to leave a minimal impact on the populations of these magnificent animals here in Madeira while using our time out at sea as efficiently as possible by raising awareness on important environmental issues affecting our oceans. Very often, the encounters speak for themselves and demonstrate how human beings impact the dynamics in our oceans.

Our guests aboard the Ribeira Brava were witnesses to such encounters this morning. First, our spotter called to inform us of a juvenile Mediterranean monk seal (Monachus monachus) near the aquaculture in front of Calheta. The animal was foraging between the cages of the fish farms so we didn’t manage a sighting but the animals interaction with these enclosures is one of many we had encountered in the last months. Fish farms can change the coastal ecology of a region dramatically by luring in predators who then gather in the area to feed, which is something that can turn out to be quite problematic. The Mediterranean monk seal is the most endangered seal species in the world and Madeira hosts one of the worlds most important communities which mainly resides in the protected area around the Desertas islands in the Southeast.

Monk seals aren’t the only marine mammals that interact with fishing gear. We’ve had several sightings of Bottlenose dolphins (Tursiops truncatus) in the vicinity of Black scabbard fishing boats reeling in their long lines and have even heard reports from fisherman where the dolphins snatch their catch and damage the lines. We saw three separate groups of bottlenose dolphins engaged in this activity today and all but one individual, paid little attention to our boat as they repeatedly dove to steal more fish. The black scabbard fish inhabits waters deeper than 800m, making it an unlikely prey of Bottlenose dolphins under natural circumstances. In their attempts to snatch the catch, dolphins may also get injured and the fishermen lose their catch; so the fact that such interactions are problematic almost goes without saying.

These sobering sightings left room for more hopeful encounters aboard the Stenella in the afternoon. However, after a long hard search that took us all the way to Funchal, we unfortunately returned to Calheta without a sighting. Despite the fact that it was a challenging day at sea, our team appreciates these days as much as all the others. Another important part of what we do is acknowledging that nothing is to be taken for granted and to understand humanity impact on our oceans and its consequences.

By Paula Thake

Sightings of the day

Ribeira Brava

10:00 Bottlenose dolphins

Stenella

15:00 No sighting