Wetlands of Costa Rica

February 2nd is World Wetlands Day, and there’s plenty of good reason to commemorate them. Wetlands are present on every continent except Antarctica! They also have a wide range of biodiversity, depending on the locations they form. A wetland is defined as an area of land that is naturally covered by water, either seasonally or permanently.

Because they exist in so many different places, wetlands have many names: peatlands, bogs, potholes, mires, swamps… All these are types of wetlands, each with a distinct appearance and dynamic. Scientists consider that the most common types of wetlands are marshes, bogs, and swamps.

As a tropical location, Costa Rica has its fair share of freshwater wetlands. They are present from the lowlands of the coastal areas to the peat bogs of the highest mountains. They are also transition zones! Wetlands are never totally dry nor totally flooded, presenting characteristics of both underwater and land ecosystems.

Vegetation is determined by the saturation of the soil. Plants that grow on wetlands are called hydrophytes and usually are uniquely adapted to high concentrations of water. However, some seasonal wetlands can support trees or bushes from different ecosystems. In the more saturated wetlands, grass and moss comprise the majority of the vegetation.

The importance of wetlands as an ecosystem cannot be overstated, especially in Costa Rica. A crucial role is that wetlands are used by both migratory and resident birds. Those that migrate use wetlands as resting and feeding grounds during their travels, while resident birds depend on them for reproduction. A myriad of other fauna also need wetlands for shelter, food, or drinkable water. In addition, wetlands act as giant sponges, absorbing excess water from heavy rains and preventing the flooding of nearby areas.

And it doesn’t stop there: they also function as natural water-treatment mechanisms. The algae, fungi, and plants in wetlands can filter wastes and purify chemicals from the water they absorb, even those from farms or towns. And those contaminants that the flora can’t absorb often sink to the bottom of the wetland. Then they are hidden below the sediments, preventing them from spreading to other ecosystems.

If humans are careful and respectful, they can also take a close look at wetlands. Usually, they are used as recreational places, depending on their conditions. They sometimes are good for nature hiking, canoeing, or birdwatching, for example.

The main problems wetlands face have started because they are often considered wastelands. The spongy soil is difficult to plant and build on. They house wildlife perceived as pests (like caimans and mosquitoes). The list goes on. Throughout most of history, the common practice has been to drain wetlands. This way, people reasoned, there was space for more worthwhile pursuits such as housing, schools, agriculture, and cattle farming. This train of thought has been so common that there is evidence that, in Costa Rica, some bogs suffered human interference as early as 4,900 years ago.

Today, we understand better than ever that wetlands are invaluable to both nature and ourselves. However, it’s hard to fight old ways of thinking. Wetlands are still disturbed by agriculture and pasturing. Uncontrolled fires, artificial drainage, water diversion, sand extraction, and pesticides are some of the most common practices that hurt wetlands. And did you know fertilizers can cause harm too? Excess of nutrients in water sources stimulates plant growth. The excessive density of the plants results in fish dying because they can’t obtain the oxygen they need from the water. This process is called eutrophication.

Tourism development is also a big problem. Indiscriminate practices allow the destruction of wetlands when building complexes for tourists. Illegal fishing and the introduction of alien species (such as tilapias) for farming also cause great damage to the ecosystem. Climate change is also a big threat to wetlands, especially in the long term. When water levels and ocean acidity change too fast, the flora and fauna can’t keep up. But remember: these are all human-provoked events. Which means we can help the ecosystem recover!

Costa Rica has significantly improved its protection practices for wetlands since the 1980s. In this decade, many wetland areas were included in the National System of Conservation Areas (SINAC). This project also proved that much of the damage done to wetlands can be undone. And pretty fast, too.

The famous wetland within the Palo Verde National Park saw recovery of its seasonal flooding patterns once agricultural fields were abandoned around the park’s main river, Tempisque. This led to many birds reestablishing healthier numbers in their original habitats. It also saved them from completely disappearing from the area. All by relocating farms!

There is much more we can do to help wetlands, and visitors can help, too. Always be respectful of both the flora and fauna you encounter, minimizing disruption. Make sure to pick up your trash and to teach best practices to those who don’t know them. Always choose a reputable tour guide that shows a serious commitment to ecology. All the little measures will add up and go a long way, and all of us will have more beautiful wetlands for a while yet.

Costa Rica has over 350 wetlands, covering over 350,000 hectares. That’s an impressive 7% of the country’s territory! Around 30% of these wetlands are protected in national parks or wildlife refuges, making them easily accessible. All of them are rich in both flora and fauna. In Costa Rican wetlands, biodiversity changes fast depending on the current conditions so it is hard to estimate its density accurately. So many species show up that you’ll never know what you could find next!

Depending on the wetland’s location, you’ll spot small plants like herbs and sedges or big ones like bamboos, palms, and even trees. Ferns, bromeliads, grass, arrowheads, pond apples, orchids, and countless more are all part of the wetland ecosystems of Costa Rica.

The fauna variation is also considerable. Crustaceans, fishes, mollusks, and reptiles such as crocodiles and lizards live in the waters. Amphibians such as frogs and salamanders also move among the crevices. Even large mammals such as tapirs and, against all odds, manatees, have been spotted on specific wetlands in some parts of the country.

However, the most abundant type of animal in wetlands is birds. This is why birdwatching is the main activity for any nature lover visiting a wetland. Hundreds of bird species come to the country’s wetlands every year. This includes the famed jabiru storks, Anatidae ducks, egrets, herons, and many more. The mangrove hummingbird (Amazilia boucardi) is an endemic species of Costa Rica that lives in both wetlands and mangroves.

Costa Rica has some famous locations to explore wetlands. The Palo Verde National Park in Guanacaste houses the richest freshwater avifauna in all of Central America. The Caño Negro Wildlife Refuge, in the northern lowlands of Costa Rica, has 6,000 ha of seasonal marshes. The Gandoca-Manzanillo Wildlife Refuge near Puerto Viejo is famous for its natural beauty. Coco’s Island National Park is a Wetland of International Importance under the International Wetland Convention. The mangroves of the Térraba-Sierpe Delta in the Osa Peninsula are a fantastic example of how much biodiversity a wetland area can have. And for those staying in Arenal Volcano, Lake Arenal is a close wetland to explore.