Spanish fishers in Galicia are reporting a “catastrophic” collapse in shellfish populations, with some stocks plummeting by up to 90% in just a few years.

As Europe’s leading shellfish producer and the world’s second-largest mussel supplier after China, Galicia has long relied on its rich marine resources. However, new figures from a fishing website highlight a sharp decline in key species. Cockles and clams, gathered by hand at low tide, have suffered devastating losses, while mussels, traditionally farmed on ropes suspended from wooden rafts called bateas, are at their lowest production levels in 25 years.

In 2023, cockle harvests dropped by 80% compared to the previous year, while some clam varieties declined by 78%. Mussel production, which stood at 250,000 tonnes in 2021, fell to just 178,000 tonnes last year.

María del Carmen Besada Meis, head of the San Martiño fishers association in the Ría de Arousa—one of Galicia’s main shellfish-producing areas—attributes this crisis to climate change. She points to recent torrential rains that have significantly reduced the salinity of the rías, or coastal inlets. Rainfall in the region has been well above average for the past two years, disrupting the delicate marine balance.

“But we don’t have enough concrete evidence and what we’d like is for someone to come and do some proper research so that we know what’s behind this and what we can do about it,” she says.

“We’re marisqueros (shell fishers) and we don’t know what the solution is, which is why need scientists to help us with this,” says Besada Meis. “The government needs to put some money on the table for this research.”

Pollution is another major threat. Marta Martín-Borregón, oceans campaigner for Greenpeace Spain, describes the latest figures as “catastrophic” and warns of worsening conditions if pollution continues unchecked.

“The biggest cause is pollution from waste discharged into the estuary, from agriculture and from factories, such as the fish canneries,” she says.

The Galician water company reports over 2,000 instances of waste being dumped into the sea annually, with 10% exceeding legal toxicity levels.

Further concerns arise from industrial projects that could intensify environmental damage. Plans to reopen the nearby Touro-Pino copper mine pose a risk of increased waste contamination. Additionally, Greenpeace strongly opposes a proposed cellulose plant, which would consume 46,000 cubic meters of water daily—equivalent to the entire surrounding province of Lugo.

“The waters of the rías are normally cold and the currents bring a lot of nutrients. With warming seas there are species of shellfish that can’t thrive in warm water,” she says. “This is especially the case with mussels and as the temperatures rise the shellfish industry is moving closer towards collapse.”

Beyond pollution and excessive rainfall, other factors are exacerbating the crisis. Dams releasing fresh water into the rías at low tide further dilute salinity, leading to mass mortality in bivalves, especially cockles.

Meanwhile, rising sea temperatures have attracted invasive species, such as the aggressive blue crab, originally from the western Atlantic and Gulf of Mexico. This predator is decimating local species like spider crabs and velvet crabs, both of which are highly valuable in the seafood market.

The only positive development is a slight increase in oyster production. However, with shellfish stocks at historic lows, pollution unchecked, and climate change intensifying, the overall outlook for Galicia’s fishing industry remains dire.

“We can’t make a living like this,” says Besada Meis. “We carry on working but we’re living on social security.”