“When the fishing ended, I wanted to die because that’s what I knew how to do. I knew how to work the clams. I knew everything,” recalls Arturo Agüero, a fisherman from La Coronilla, a small fishing village in Uruguay.
It was 1994 and, in view of the enormous mortality that decimated the populations of yellow clams, the Uruguayan authorities opted for the total closure of this fishery in the Department of Rocha to avoid its local extinction.
This decrease was no more than a direct consequence of the systematic increase in sea surface temperature that had been recorded for several years, particularly after moving from a cold to a warm period during the 1990s.
The warming of the oceans results, in part, from the increase in greenhouse gas emissions, especially carbon dioxide, which traps solar energy within the atmosphere, which generates a tropical expansion that is driven by temperature gradients that advance towards the oceans. poles at mid-latitude.
This increase in temperature changes the intensity and direction of the winds, which affects the circulation and currents of water.
These long-term changes reduced polar ice sheets, altered precipitation regimes, and implied a rise in sea level.
Ocean warming shows a clear signal in the Western South Atlantic Ocean, particularly over the continental shelf of southern Brazil, Uruguay and northern Argentina, one of the largest maritime hot zones in the world.
The adjacent basin of the Rio de la Plata is also subject to intense warming. The current from Brazil shows a consistent shift towards the pole, and the advance of warm waters towards the slope in the northeast of Uruguay has been reinforced by the increase in the speed and frequency of the winds towards the coast.
Artisanal fisheries in developing countries are particularly vulnerable to the effects of climate change.
Warming oceans have been responsible for the mass death of species with an affinity for cold water, the increasing occurrence of red tides (harmful algal blooms) and a shift from cold water species to warm water species.
Thus, fishing communities that depend on marine resources are increasingly threatened by rising ocean temperatures.
In the case of the yellow clam of La Coronilla, the mass die-offs led to the closure of fisheries, in which fishermen were forced to diversify their livelihoods into local sectors of the economy, such as construction, agriculture and logging, or forced to migrate.
This shows that the socio-ecological system of the zone as a whole, including governance, society and economy, was not prepared to face drastic changes.
In the summer of 2009, after 14 years of fishing closures, fishing families returned to extracting clams on La Coronilla beach, a tradition passed down for generations. But given the small volume of clams, the fishery was reopened with a catch of just three tons.
Product quality was then prioritized over quantity, and a co-management regime was implemented, whereby fishermen formed part of the discussion of fisheries management measures.
This time, in a joint effort of fishermen, government and university, the Rocha family, with a wide fishing tradition of several generations, embarked on the commercialization of clams based on products with higher added value.
This is how, thanks to the impulse of this family and the support of the government, the first plant to process and purify the product to meet the standards for human consumption was born.
This milestone allowed the product to start being sold at a higher price in restaurants in tourist resorts on the Uruguayan coast, which positioned it as a gourmet product.
However, despite the efforts of fishermen, and due to changing climatic conditions, supply still cannot be guaranteed.
The supply is not only affected by the scarcity of the resource, but is also reduced by the constant clashes of the red tides, whose origin is largely due to the heating of the water, and which force the fishery to close due to the risk of intoxication.
The number of days of red tide shellfish harvesting off the coast of the Uruguayan ocean has increased, particularly since the early 2000s. This has affected inshore fishing and severely limited the yellow clam fishery in La Coronilla.
“When a red tide occurs, we have to stop fishing and request an extension of the fishing season. This is a partial solution, as sometimes we end up working in the winter, when only 20 kilos of clams can be sold. “, says one of the fishermen.
This problem, however, is not limited to Uruguay. Similar fisheries have been harmed in Latin America, including clams on the Peruvian and Chilean Pacific coasts.
The effects of climate variability generated by El Niño events decimated the Peruvian clam, whose fishing has remained closed since 1999 and has led to socio-ecological collapse.
In the case of clams exploited in Chile, the 2015-2016 El Niño decimated populations and also led to the closure of fisheries for several years.
Although the analysis of the effects of uneven ocean warming has gained attention in the last ten years, the lack of data in developing countries often does not allow an adequate scale of the damages.
However, it is evident how rising sea levels and winds towards the coast cause erosion, beach retreat and loss of dunes. By 2100, up to 70% of southern California’s beaches will erode, and El Niño events have already eroded parts of the Pacific and Atlantic coasts.
The intensification of climate change, acting in conjunction with other anthropogenic impacts, will increase the vulnerability of coastal systems, which will reduce their ability to provide services and benefits related not only to fisheries, but also to recreation, tourism, habitat rich in biodiversity and coastal storm protection.
This has had and will have ever-deepening socio-economic consequences for the communities that inhabit the coasts of Latin America.
