Incidental catches in fishing gear

Who hasn’t already heard of whales that die after getting caught in fishing gear? But did you know that in certain cases, this problem is so serious as to endanger entire populations? Here are a few examples of this type of incident around the world, a vast problem with no one-size-fits-all solution.

Vaquita

The vaquita, a species of porpoise endemic to the Gulf of California, numbers no more than a few hundred individuals. However, 30 or 40 vaquitas are estimated to perish every year in the gillnets and shrimp trawlers of Mexican fishermen. Even if the vaquita’s fate is alarming, imposing drastic solutions to the fishing-related mortality issue is difficult. Indeed, it would be unthinkable for Mexico to forbid fishermen struggling to provide for themselves and their families from fishing, which is the only social and economic motor in this desert region. Three countries are involved in porpoise conservation: Mexico, the United States and Canada. The conservation measures implemented; the sanctuary zone off limits to fishing with its financial compensations deemed by fishermen to be insufficient; attempts to employ new fishing methods; permitting; and illegal practices: for the time being, nothing seems to ensure the vaquita’s future. Its survival is tied to that of local communities and to the economic diversification of their region. A vision and new, creative actions common to all stakeholders must be structured around this twofold challenge.

Great whales also at risk

Generally speaking, small coastal cetaceans like the vaquita are more sensitive to incidental catches, either because they are drawn to captured fish or because they don’t recognize the danger that fishing gear represents. Even the great whales are not safe from incidental catches, as evidenced by the North Atlantic right whale. This species was nearly driven to extinction by whaling at the end of the 1800s. Today, far from having rebounded following several decades of protection, the right whale is endangered. A mere 490 were counted in 2011, and bycatch in fishing gear represents the second most important cause of mortality. Despite numerous measures put into place (modifications to fishing gear, educational material for fishermen, etc.) in an attempt to reduce the risks of collisions and incidental catches, mortalities continue to this day. In addition to being dangerous if not deadly for whales, these entanglements are costly for fishermen, who must replace lost or damaged ropes and traps.

In the St. Lawrence

The magnitude of this problem in the St. Lawrence is not well known. Off the coasts of Newfoundland, when cod fishing was at its peak, humpback whale bycatch was a major issue. The situation led Jon Lien to assemble a team of specialists that, in collaboration with fishermen, has been freeing trapped whales since 1978. The real impact of bycatch on other species inhabiting the St. Lawrence is poorly understood, but every year, minke, humpback and even blue whales are reported entangled in nets or ropes.

The story of Tryphon

In June 2009, the best known sperm whale of the St. Lawrence, Tryphon, was spotted trapped in crab trap ropes off the coast of Sept-Îles. Despite the fact that some of the ropes had been removed and the close monitoring of the response teams, his carcass – still wrapped up in the ropes – was found floating in the Estuary a few days later.


© GREMM

The story of Capitaine Crochet

© GREMM

  • Crédit photo : © Gremm

Capitaine Crochet is that well known fin whale in the Tadoussac region that had gotten herself ensnared in fishing gear in the spring of 2013. This female had returned every spring since 1994 and had even escorted a few calves over the years. The incident had mobilized numerous experts to attempt to free her, stirred up strong emotions amongst those who had known her for years and created a bit of a media buzz. Despite all these efforts, the animal could not be freed; she left the Marine Park one week later and has never been seen since. It is assumed that she died given the seriousness of her entanglement.

Solutions… ?

Of course, ideally we could prevent bycatch. But that’s easier said than done… For example, in the Gulf of Maine, every year harbour porpoises die by the thousands in fishing gear, and to date none of the solutions tested has led to a significant reduction in these mortalities. To keep the porpoises away, sorts of “acoustic scarecrows” are placed on the nets. The results of this technique are inconclusive, as it seems to work in some cases and remains ineffective in others. The same can be said for fishing zones and seasons established with the objective of minimizing conflicts between fishing activities and harbour porpoises. The problem is all the more worrying in that we have here one of the best contexts to tackle the problem: American law is strict in terms of protecting marine mammals, and teams comprising scientists, fishermen and other concerned stakeholders have been working for a number of years to reduce incidental catches. It must therefore be concluded that the problem is a complex one, and hope that the creativity and perseverance demonstrated in the case of porpoises in the Gulf of Maine will also serve as an example for addressing bycatch issues elsewhere in the world.