Alert in Galicia for the lack of shellfish: "The sea is stopping producing"

Galician shellfish workers are restless.

Rita Míguez has been planting and collecting delicacies in the Vigo estuary for 16 years and her opinion is clear: “The sea is ceasing to produce.

You reserve an area without working for a year and, when you go and expect to find commercial-sized clams, there is nothing.

We are very worried about our future.”

200 kilometers away, in the wild Rías Altas, "the descent is tremendous", agrees Cristina Fernández, spokesperson for the shellfish workers of Cariño (A Coruña).

In the laboratories of the University of Vigo they have found at least part of the answer and it has to do with the meteorological phenomena of climate change.

Míguez, president of the Arcade (Soutomaior-Pontevedra) shellfisher association, explains that every year she and her colleagues invest their money and effort in planting certain areas, but the bivalves no longer grow or directly die: “Years ago, the 80%, today it does not reach half”.

The problems began to be noticed eight years ago with the fine clam.

They stopped taking her so she could recover, but they couldn't, "everything dies" without remedy.

Now the same thing is happening with the theoretically most resistant variety, the japonica.

And the cockle, decimated by a parasite for a decade, is not raising its head either.

From Cariño, Fernández says that in March 2021 they stopped extracting clams because there are no more.

And with the longueirón, another species that is unearthed from the sand, they are on the same path.

Pollution, invasive species and climate change are some of the factors that are handled in the shellfish sector as the cause of this decrease in catches.

The shellfish workers urge measures.

“The Xunta, the brotherhoods and the universities have to sit down.

Scientists have to find out why and if something needs to be changed, we change it.

The shellfish women pamper our environment because it is what feeds us.

We will do what the technicians tell us,” says Míguez.

From the richest estuary in Galicia, the spokesperson for the shellfish gatherers of A Illa de Arousa, Carmen Dios Castro, believes that there is still "time to do something before things get worse": "We shellfish gatherers do our job because it is our survival, but there are problems that we do not know what causes them or how to deal with them;

We don't have a college degree

Elsa Vázquez Otero, professor of Zoology at the Faculty of Marine Sciences of the University of Vigo, has some of the answers to the questions raised by shellfish gatherers, who has spent years investigating some of the factors that can explain these changes.

Since 2014, her team has investigated the effects that the low salinity of the sea and the heating of the sand have on the bivalves, caused by the increasingly frequent episodes of torrential rains and heat waves in Galicia.

These researchers reproduce real conditions in the laboratory that have already occurred on the Galician coast and then observe what happens with two of the most demanded species in the markets: clams (both the fine one and the slug and the japonica) and the cockles.

A shellfisher, in the Vilanova de Arousa area.ÓSCAR CORRAL

The unusual torrential rains that have hit Galicia in recent years have come to lower the salinity of the sea, abruptly and for days, up to 60%.

If the normal parameters inside the estuaries are around 30 grams of salt per liter of water (a little less in winter), Vázquez and his team have obtained measurements of between 5 and 10 grams per liter after extreme downpours. .

The zoologist explains that, in such hostile conditions, clams and cockles close up tight to protect themselves, waiting for the tide to rise and increase salinity.

But as the situation persists, finally they have no choice but to open their shells and the "shock" with such a little salty sea "gets their physiology out of control."

"If that happens for several days, the bivalve can't take it anymore, it's not able to resist and it dies," she warns.

Yes,

Something similar happens with extreme temperatures.

In heat waves like this summer, low tide is an oven for bivalves.

Vázquez explains that clams and cockles bury themselves as much as they can in the sand looking for freshness, but they can only do so up to the top: the length of the tubes called siphons through which they breathe and which have to reach the surface.

The effects of this stressful situation are repeated: death and decline in growth and reproduction.

"In June we simulated a four-day heat wave and we just had a six-day heat wave," says the scientist.

In the Arousa estuary, brotherhoods of fishermen and environmentalists, united in a platform that for years has denounced the deterioration of the area, focus on the official data of the Xunta.

According to these records, clam production has fallen by less than half since 2000, and cockle production has been falling since 2008, reaching only 23% of extractions last season.

The shellfish workers of A Illa de Arousa agree that the change in the number and size of bivalves "is a palpable reality throughout the estuary" that has worsened even in the last two years.

"For years we have noticed the gradual decline of the cockle, which was an economic mainstay for the sector, and a slowdown in the growth of the clam, but the last two years have been fateful and we are facing a decline in production," laments Carmen Dios. .

In this estuary, 75% of the bivalve production is already obtained by providing seed because, otherwise, there would be practically no specimens to sell.

“When I was a girl, on the beach, to get a handful of sand to make a castle, you had to separate the shellfish, but today that abundance is part of the past and we are stuck in a vicious circle that has not been clarified.

And the proliferation of algae due to the use of fertilizers is also depriving the species of oxygen”, explains Dios, who has been a shellfisher since she was 14 years old and is now 46.

The Consellería do Mar de la Xunta recognizes the influence of climate change on shellfish production, but also points to other factors such as pathologies, predators or exceptional situations such as the pandemic.

In his opinion, the variations that show the quantities of shellfish extracted, both upwards and downwards, reveal that the effects on production are unequal according to the zones.

Last year, more than 7,000 tonnes of bivalve molluscs were sold in Galician markets, a figure slightly lower than the 8,000 sold on average since 2014. The poor situation of some estuaries, he says, is compensated by that of others that are better.

Faced with the scientific studies that the sector constantly demands, Mar defends the "constant monitoring" of the state of the shellfish banks that is being carried out and the "intense" work that is carried out in collaboration with the fishermen's associations where decreases in the production.

"We understand that the impact of climate change should be generalized, but the analysis of the data shows that there are areas, regardless of their geographical location, that are in a worse situation, such as the Arousa and Ferrol estuaries, in which work is being carried out intensely to boost their productivity, while others are achieving good results, such as the Muros, Noia and Pontevedra estuaries”, underlines the ministry.