Fish traps sold in Finland endanger Saimaa ringed seals

Thirteen Saimaa ringed seals have died in fishing gear this year, more than twice the average for the past decade, Yle reports. Some fish traps sold in shops are dangerous to the seals because their entrances can stretch wider than 15 centimetres.

Loose entrances are typically found in light, inexpensive traps that fold into a small space. They must be modified to make them safe for Saimaa ringed seals. Other traps are already safe.

Ismo Marttinen, a conservation coordinator at WWF, said fishermen are responsible for checking whether their gear is suitable for the location. He noted that loose-entrance traps are permitted in some Finnish lakes.

Miina Auttila, a senior conservation specialist at Metsähallitus, said three seals are known to have died this year in traps with loose entrances. Metsähallitus has been notified of 13 seal deaths in fishing gear in total.

That figure is high compared with the average of six seals killed in fishing gear each year during the past decade. Metsähallitus estimates that it learns about roughly one in three such deaths.

Most deaths occur in nets

The most common cause of death in fishing gear is entanglement in a fishing net, Auttila said. Seals typically drown after becoming caught in a net that is legal under a government decree.

“If a seal gets slightly caught in a net, it starts spinning like a drill bit. Eventually, all the net’s upper and lower ropes are wrapped around the seal as well,” Auttila said.

Although nets account for most deaths, Auttila said deaths in fish traps would be the easiest to prevent. Following the regulations would be enough, as traps and other fishing gear with entrances that can stretch beyond 15 centimetres are prohibited year-round in key Saimaa ringed seal areas.

Marttinen demonstrates how to reduce the width of a trap’s entrance to make it safe.

Winter conditions may play a role

Metsähallitus has no clear explanation for the unusually high number of deaths in different types of fishing gear this year.

Auttila said one possible explanation could be the two recent winters, which had little snow. Poor breeding conditions may have left some young seals starting independent life in weaker condition than usual.

“Thinner and hungrier young seals may face a greater risk of ending up in fishing gear,” Auttila said.

At the same time, she stressed that a fishing gear death always requires dangerous gear to be present.

“If there were no fishing gear dangerous to seals in Lake Saimaa, seals starting from weaker conditions because of climate change would have fewer hazards to face,” Auttila said.