By Carrie Chapin and Jon Piasecki, Houston Audubon Coastal Conservation Technicians
Today (Feb 2nd) is World Wetlands Day – a yearly celebration of wetlands and their important contributions to ecosystems and human society. Wetlands provide food and habitat for thousands of species, filter water, and capture runoff to prevent flooding. A wetland is any area of land with water covering (or near) the surface of the soil for at least part of the year. Much of the 4,100+ acres managed by Houston Audubon are wetlands, including virtually all of the ~3,000 acres within the coastal sanctuaries.
There are several different kinds of wetlands that can be found in Texas, each with their own value and contribution to ecosystems. Marshes are areas that are periodically inundated with water and support only herbaceous plants. Tidal marshes are cyclically infiltrated by saltwater and can support a variety of freshwater, brackish, and saltwater species. The prairie potholes of the northern Great Plains are a type of marsh and are important breeding habitat for many species of duck and other water-birds. Swamps differ from marshes in that they support trees and other hardwood plant species and have standing water most of the year. The high level of nutrients in swamps support many invertebrates and other prey food items but also makes them targets for agricultural development. In the more arid plains regions of Texas, one can also find circular depressions known as playas. These are seasonal wetlands, primarily fed by rainfall, that may go dry for several years at a time. When full, they become a hotspot for wildlife.
Despite their disproportionate impacts on ecosystems, wetlands are some of the most imperiled habitats. Pollution, introduction of non-native species, and draining for development are all threats to wetland ecosystems. However, there are things we all can do to help minimize harm to wetlands: grow only locally-sourced native plants in your garden, reduce fertilizer and pesticide use, remove used fishing line, properly dispose of chemicals, refrain from releasing pets, and volunteer with local habitat restoration groups. Together we can help preserve wetland habitats so we can enjoy the diversity of birds and other species indefinitely.
Of the many avian species that depend on wetland habitats to survive, the American Avocet is one of the most charismatic. These birds winter along the Texas Gulf Coast, where they forage around tidal mudflats and salt ponds. Flocks of over 1,000 avocets can often be seen foraging simultaneously, showing just how vital these habitats are. During migration, American Avocets use wetland habitats as stop-over sites to refuel for their flights when needed. This species breeds throughout the Great Plains using interior freshwater wetlands such as prairie potholes to sustain successful breeding seasons. American Avocets are a great example of just how important wetlands are, as they use a variety of both freshwater and saltwater habitats throughout their life cycles.
The Black Rail is another avian species of the Texas Coast that depends solely on wetlands for survival. Most of these tiny birds spend their entire lives in the coastal marshes of the mid and upper-Texas coast. The Black Rail is listed under the Endangered Species Act as it is estimated the species has declined over 50 percent during the last 50 years (and up to 90 percent in some regions). Because of the Black Rail’s size and specific habitat, this species is heavily impacted by sea-level rise, putting it at greater risk of habitat loss and degradation. Wetland restoration and protection are key to helping this species recover.
These are just two of the thousands of species of plants and animals that depend on wetland habitats to survive. Healthy wetlands are very important to creating a stable environment as a whole and without them, the world we live in would be a much different place. It is vital that on World Wetlands Day, we celebrate the beauty and importance of wetlands but also understand there is much more work to be done for the future.
Houston AuduBlog 