It’s no accident that Costa Rica ended up with so prodigious a name as “Rich Coast.” Though small, the Central American nation boasts more than 745 miles (1,200 kilometers) of coastline on two oceans, with dozens of beaches, expanses of mangroves, coral reefs and three major gulfs. Beyond those coasts, the national waters extend over more than 223,000 square miles (580,000 square kilometers) – an area more than ten times greater than the national territory – and hold five percent of the planet’s fish species.
The coasts’ estuaries are vital for commercial fisheries, whereas its beaches attract more than a million tourists each year. Unfortunately, the nation’s rich coasts are hardly pristine. With support from the Costa Rica-United States Cooperation Foundation, the University of Costa Rica’s Center for Ocean Research and Limnology (CIMAR) recently completed a three-year study that assessed pollution levels in four coastal ecosystems that are of particular economic importance.
The Coastal Contamination in Costa Rica (CoCosRI) project was a first in Latin America, according to chemical oceanographer Jenaro Acuña, who participated in the study. It was the first time in the region that four coastal sites were evaluated simultaneously, during both the dry and rainy seasons, and that tests were run for such a wide range of pollutants, in three places at each site and at varying depths.
The sites studied are also quite different from one another; one is a coral platform, in Moín, on the Caribbean, whereas the other three are on the Pacific coast: Culebra Bay, an area that experiences upwelling; the Gulf of Nicoya, an estuary; and the Dulce Gulf, an anaerobic sedimentation at a depth of 656 feet (200 meters).
At all four sites, the scientists measured more than 20 parameters, from the temperature and turbidity of the water to the presence of pollutants such as petroleum derivatives, pesticides, coliform bacteria, and solid waste. Other pollutants analyzed included heavy metals, including lead, cadmium, copper, and zinc and polychloride biphenyls, which are persistent toxic compounds present in some electronic equipment, paints, plastics, and other products.
According to Acuña, while the results don’t show alarming levels of pollution, they provided valuable information about the kinds of pollutants present in each area and can guide measures to deal with the problem. Among the results was the discovery that the Bay of Golfito, in the Dulce Gulf, has the highest levels of fecal coliforms. The scientists also noted the presence of garbage, mostly plastic, at all four study sites.
But not all of the news was bad. In the Puntarenas Estuary, next to the Gulf of Nicoya’s biggest city, where there has been a significant campaign to rescue that ecosystem, they detected only moderate pollution. An absence of persistent organic agrochemical pollution at all four study areas was another good sign.
In the case of hydrocarbons derived from petroleum products, even though researchers didn’t find levels of contamination that exceed the international parameter of 10 micrograms per liter, Acuña says the situation shouldn’t be taken lightly and needs to be controlled. Moín, the country’s principal port, was the area with the worst petroleum pollution, with parameters of up to 8 micrograms per liter, and the highest levels of lead. Approximately five million barrels of petroleum are shipped through the Caribbean every day, and an oil pipeline that runs between a refinery near Moín and the Pacific coast has suffered occasional leaks. The study also detected high levels of petroleum pollution in the Gulf of Nicoya. Studies also revealed the somewhat surprising presence of polychloride biphenyls at all four areas, principally in Golfito Bay. Use of PCBs is no longer legal, so CIMAR scientists suspect illegal dumping.
From now through 2005, the center will be running a second phase of the coastal pollution project, which consists of evaluating the impact of pollutants on the endocrine systems of marine animals such as fish and turtles, which may suffer physiological anomalies. Several research centers at the University of Costa Rica and in the United States, including the Center for Bio-Environmental Research at Tulane University, are participating in this phase of the project.
“It is quite possible that some of the biological species we’ll analyze could be affected by these pollutants, and this would be the first time in Costa Rica that we could demonstrate that it is happening,” says Acuña.
An important component of the project, she explains, is the education of local communities about its results. CoCosRi has organized workshops in the four communities closest to the study areas. Project staff also designed an educational CD with information about coastal pollution, the parameters measured by the study, and their importance; the CD has been distributed to schools, colleges, and other interested organizations.
Sonia Salas, Ministry of Education superintendent in Puntarenas, is one of several community leaders who are trying to put the study’s results into practice. She is in charge of 10 schools in the Gulf of Nicoya region, three of them on Chira Island, which is in the gulf.
Salas explains that most of the students in the schools she supervises are children of fishermen, which is why she wants to include material about marine resources in the school curriculum. “It is important that the students understand the damage pollution does to the Gulf of Nicoya, and that they learn to exploit marine resources rationally,” she says.
— Katiana Murillo
Read more about this project in the Eco-Index: