San José, Costa Rica, since 1956

Fish Samples Turn Up Clean, Risks Remain

Last in a five-part series on the challenges facing Costa Rica’s fisheries.

PUNTARENAS – It was early morning in this central Pacific port city, but already most of the night’s catch of fish had been cleaned and whisked away to hungry tourists in seaside resorts and hotels.

Fisherman Rodrigo Barrantes hosed down a filet table by the docks, blood swirling about like crimson ink on the slippery wooden surface. Others were loading the last boxes of fish into a delivery truck.

He picked up a long, skinny eel-looking fish and grinned. It was long dead and brown, and looked a bit like it belonged in a B-grade science fiction movie.

He threw it in a crate with others like it, the last load of the morning. “San José corvina,” he said, smirking, but only half-joking.

Once breaded and fried, no one would know the difference. Likewise for its origin.

It’s a problem that has raised eyebrows recently as a lack of transparency in quality and sanitary-control processes earlier this year shut shrimp fishermen out of the lucrative European Union market.

It’s also a part of the country’s dirty little secret: 97% of untreated graywater and sewage pours directly into its rivers, according to the National Water and Sewer Institute (AyA).

Much of that, by default, flows into the sea. What does it mean for the quality of the country’s seafood?

Lab Visit

The country’s testing laboratories, part of the government’s National Animal Health Service (SENASA) are found in Barreal de Heredia, north of San José.

Bubbling test tubes are set on black marble countertops, workers in lab coats bustle around, filling lab notebooks with numbers and graphs.

Chemist Laura Padilla, dressed in white and wearing latex gloves, hoisted a bag of fresh tuna onto a scale and explained that Costa Rica requires a strict process from boat to market, which includes icing, a light chlorine bath to rid products of bacteria and random testing of products heading to market.

“It’s a standardized process, and one very similar to what happens in the rest of the world’s seafood markets,” she said.

Padilla works specifically with heavy metals, including mercury, lead and chrome, which occur naturally to some extent in the environment, but which can also be worsened by contaminated runoff and rivers, she said.

She opened a book of graphs in the airconditioned laboratory, and showed a horizontal red line marking the safe zone.

Above the line, a health hazard. Below, safe. In the graphs of offshore, migratory species like tuna, shark and marlin, the average was clearly well below, but occasional spikes like ragged peaks crested the line in places.

On the graphs of corvina and pargo (snapper), two of the most commonly eaten ocean fish in Costa Rica, mercury remained well below the danger levels in all cases.

“Larger, offshore fish, like tuna and shark, tend to accumulate more mercury over time than do smaller, shorter-lived inshore species,” she said.

According to Jorge Cascante, who manages the microbiology lab next door, contaminants such as salmonella, E. coli and other bacteria, which can cause serious health problems, rarely, if ever, make it to the market.

“There is a reason why you rarely hear about such problems with our seafood in the media.We catch them first,” he said.

Despite the occasional occurrence of contaminants in fish species, the country offers no general health warnings to the public, Padilla said.

Recently, the Production Ministry closed down shrimp vendors in Puntarenas, for not complying with health standards, according to Padilla.

In the United States, the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) “are advising women who may become pregnant, pregnant women, nursing mothers and young children to avoid some types of fish and eat fish and shellfish that are lower in mercury.”

There are no blanket warnings as in the United States, but Padilla said doctors in Costa Rica often warn pregnant mothers against eating fish like tuna and shark during pregnancy, but for everyone else, she said, you take your chances.

According to Cascante and Padilla, the country’s shrimp remains marooned here largely because it has yet to satisfy the documentation processes required by the European Union, not because the shrimp are unhealthy.

The United States, also stringent about the seafood allowed to cross their borders, currently accepts shrimp from Costa Rica.

Polluted Rivers

According to Hannia Vega, a marine biologist with the National University (UNA) and a specialist in fish and seafood contamination, Costa Rica’s inshore fisheries are likely safe from contaminants, though scattered danger areas exist.

While the country doesn’t close any areas to fishing, areas known to contain heavy loads of pollutants, such as some places in the Pacific Gulf of Nicoya, see more testing than others, she said.

Vega recently completed a study on contamination with the Japanese International Aid Agency (JICA), which included a look at shellfish contamination near the mouth of the Río Tárcoles, a river with the reputation as a surrogate toilet bowl for the Central Valley.

Though the results of her study are still pending review, she said certain species of clams and mussels from the area showed abnormally high levels of heavy metals that would be toxic to humans.

“We’re always worried about the possibility of contamination, particularly at the mouths of Costa Rica’s most polluted rivers. It’s obvious there’s a problem there,” she said.

But according to Cascante, of SENASA, such problems are monitored and seafood is removed from the market if it poses any danger.

“We can’t possibly monitor every batch – no country in the world does that. But random sampling helps us monitor the situations in different areas throughout Puntarenas,” he said.

Put to the Test

The Tico Times obtained two fish samples from vendors in Puntarenas: a corvina from a ramshackle fish house just a few paces from the docks, and a snapper from a tidy fish market where the salesmen wore white smocks, hairnets and latex gloves.

The next day, in San José, we dropped the two fish off at Aqylasa, a chemical and quality control laboratory in Curridabat, east of San José.

The results came in one week later: the fish were clean of chrome and lead, two potent heavy metals, but came back with moderate levels of mercury, 0.256 parts per million (ppm) in the snapper, and 0.221 ppm in the corvina.

We consulted Hannia Vega, who was hardly surprised by the results.

She advised that these were just two fish in a big sea and added that the levels, while elevated, where still well below the safety standards set by the U.S. Food and Drug Administration, which state that any fish testing at more than 1 part per million should be taken off the market.

Trace amounts of mercury are common, she explained, since it is naturally occurring in the environment and found throughout the world’s oceans. Finding mercury in short-lived inshore fish like corvina and snapper is less common. Oceanic species like tuna and shark, particularly in Costa Rica, often have elevated levels, though usually below the dangerous level.

According to Laura Padilla, of the government’s testing laboratories, women should consult their doctor before eating any fish during pregnancy.


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