22.04.2019 – A question of method

Both our boats had to venture far east, to the waters outside Ribeira Brava, to encounter a group of Bottlenose dolphins (Tursiops truncatus). I was aboard our traditional boat with a lovely group of guests who all showed so much interest in the animals and the variety of marine life around Madeira.

A frequently asked question during many of our tours is the effect of fishing on the marine mammals around Madeira. Generally the relationship of a specific human action to the environment is divided into two categories; direct and indirect effects. Fishing affects marine mammals indirectly by reducing the availability of their prey and, considering that we are further exploring an extremely overfished ocean, this can have dramatic consequences. This, for example is the case with the Short-beaked common dolphins (Delphinus delphis) in the Mediterranean, that are critically threatened due to extreme prey depletion. Often marine mammals are so desperate for prey that they resort to stealing catch from fishermen, which in some places (thankfully excluding Madeira) has lead to fishermen killing dolphins.

Of course there are also the direct effects caused by specific fishing methods, some of which are also practiced here in Madeira, that cause a substantial amount of injuries and deaths in cetaceans. Long-lining, for instance, is a questionable fishing method that is used to catch the Black Scabbard fish (A.carbo) a deep-sea fish that is a known delicacy on the island. These lines extend up to 2000m into the depths and, apart from causing a large amount of by catch, also injure cetaceans that swiftly swim by. Big-game fishing boats can also injure cetaceans and abandoned fishing gear causes entanglement, primarily in younger cetaceans.

At the end of the day you could say that it is the method that determines the effect. People often make the mistake of demonising fishermen but not all fishermen act irresponsibly… just as not all ecotourism institutions act responsibly. Not all whale-watching in the world is properly regulated and not all companies have the animals well-being as their top priority. Madeira is full of people that practice self-sustainable fishing methods such as spearfishing or spinning, which, if practiced carefully, have less of an impact on marine life.

In my opinion it isn’t always about what you do, how you do it, can play an even bigger and more vital role when it comes to our relationship With the natural environment.

By Paula Thake

Sightings of the day

Ribeira Brava

10:00 Bottlenose dolphins

Stenella

10:00 Bottlenose dolphins