Exploring the wetlands in the CNMI

CoCo here, and have I got a treat for you this week! We’ve got a special guest in to tell you about wetlands. If you’ve ever wondered what a wetland is, here’s Coastal Resources Management’s Hilary Stevens to tell you all about them! Take it away, Hilary!

Wetlands are just what they sound like, areas with lots of water. There are different kinds of wetlands. Some are near the coast, and have salty water. Some are in low-lying areas, where water tends to collect after rains. Many wetlands are strongly affected by weather and seasonal water supply. Although there are several wetland areas in the CNMI, many people don’t know much about them. Some are easier to get to than others, but even these wetlands are areas that people don’t commonly visit and enjoy. They are thought of as mosquito-infested, undesirable lands, and have historically been filled and converted to solid ground. But we need to protect our wetlands as part of our natural heritage. Here in the CNMI, wetlands are particularly important because we have such limited freshwater resources.

One reason wetlands are so significant is that they are a unique habitat for wildlife. Here in the CNMI, we have a number of birds that need wetlands to survive. The Mariana moorhen, called pulattat in Chamorro and gherel bweel in Carolinian, lives in wetlands. It prefers open water for its habitat, and is endangered. The nightingale reed-warbler, called ga’ga’ karisu in Chamorro and litchoghoi bwel in Carolinian, is another endangered species that favors the wetlands. It prefers more vegetation than the moorhen, but they can be found in the same area. There are also many types of plants that only grow in wet areas. In fact, scientists use these plants as one way of defining a wetland. Taro and kangkun are two examples of food plants that grow in wetlands.

Wetlands help to improve water quality by filtering water as it slowly moves through soil. They can also reduce flooding and sedimentation problems by slowing the movement of water. The Army Corps of Engineers is currently researching the water in and around Lake Susupe in order to better understand the water cycle in that area.

Lake Susupe is surrounded by wetlands, as anyone who lives near knows. The entire area is frequently flooded after heavy rain. This is common around wetlands, which is one very good reason not to build near them. Wetlands in the CNMI are protected by law. Building on or filling in a wetland requires a permit, and is generally not allowed. Lake Susupe also has an interesting place in Saipan’s history. The bottom of the lake is deeply covered with sediments, organic matter that has accumulated over many years. Much can be learned about the people that lived in the area as well as natural history by studying these sediments. For example, pollen indicates how the array of plant types has changed, and the presences of ashes in the cores show when people started living in the area.

The mangroves near Smiling Cove are also in a wetland. Mangroves are trees that can grow in soil that is totally saturated with water. Almost all mangrove species are tropical, and they provide good habitat for crabs, juvenile fish and other species. In many tropical countries, mangroves are being cut down to provide wood and to clear coastal areas. Mangroves also tend to accumulate trash that floats in the water, which is ugly and ruins the habitat. Help prevent this problem by putting your trash in the proper place, and picking up trash when you see in on the beach or in the ocean. Saipan has only a small area of mangroves left, so it is important to protect what remains.

Lake Hagoi on Tinian is a large wetland area that is still in very good condition. It is fairly isolated from human activity and surrounded by dense vegetation. Rota also has numerous wetland areas resulting from freshwater springs.

You can learn more about wetlands by going to visit them and exploring the different kinds of plants and animals that live there. Listen for birds, and look at the different ways that plants grow in these areas. The Coastal Resources Management Office is updating its maps of all the wetlands on Saipan, Tinian and Rota. Come ask us if you have wetlands near your home, and learn to love these important elements of our natural heritage.