Año de Publicación
2025Breve descripción
TWS Lake O The Pines March 2020
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Texto Completo
Dissolved Oxygen — What is the Forest’s Role? In 2000, it was determined that that dissolved oxygen (DO) levels in Lake O’ the Pines were less than optimal for supporting fish and other aquatic species. Since then, local stakeholders such as industry and private landowners in the Lake O’ the Pines watershed have been invested in remediating these low oxygen levels because of the harm it can cause ecologically and economically to the watershed. Even though a stream on forested property may be away from the Lake O’ the Pines, the management or lack of management of that property can have consequences downstream. DO is a measure of how much oxygen is dissolved in the water – the amount of oxygen available to living aquatic organisms. Oxygen enters water by diffusion from the air, as a byproduct of aquatic plant photosynthesis, and by aeration through water movement. The amount of dissolved oxygen in a stream or lake can indicate a lot about its water quality. Multiple factors and pollutants can impair or reduce DO such as increased water temperature and excessive nutrients, oils, and other chemical compounds. Organisms within waterways such as fish, invertebrates, plants, and bacteria require DO for respiration. When DO falls below a certain threshold, some organisms cannot live. Best Management Practices (BMPs) can be implemented to protect dissolved oxygen levels during forest management activities. For instance – during harvest activities, it is recommended to leave a streamside management zone (SMZ) along streams. SMZs help DO by shading the stream, keeping the water cool. Cold water holds more oxygen than warm water. The roots of trees and other plants within the SMZ help to hold soil in place, keeping it from eroding into the stream. SMZs also slow down water that may be flowing across the landscape carrying soil, leaves, limbs, pesticides, herbicides, and other pollutants. Once entering the SMZ, these pollutants are allowed to settle out before entering the stream. Naturally occurring leaves, limbs, and logs in streams play an important role in ecosystems as habitat and food sources for fish and other aquatic organisms. However, too much of this organic matter can accumulate if it is regularly being dumped into the stream by water flow from the land. As this organic matter decomposes, oxygen in the stream is used up, leading to lower DO levels. Caddo Lake Institute Caddo Lake Institute (CLI) is a non-profit scientific and educational organization founded in 1992 with the mission of protecting the ecological, cultural, and economic integrity of Caddo Lake and its associated wetlands and watersheds. The Institute address issues such as the need to return healthy flows of water to the lake, restore water quality in the watershed, control invasive species, and conserve significant lands. CLI’s work is not just limited to Caddo Lake due to the environmental influence of neighboring watersheds. In order to promote the water quality and health of Caddo Lake, CLI works with other local watersheds to promote the overall health of the Cypress River Basin. Projects of importance to them include the restoration of the American paddlefish, securing adequate instream flows to sustain the ecological role of the watershed, removal and management of harmful invasive species, and the restoration of wetlands. In 2010, the EPA awarded a technical assistance grant (TAG) to Caddo Lake Institute to obtain the services of a technical advisor to analyze technical reports pertaining to cleanup of contamination at the Longhorn Army Ammunition Plant near Karnack. The Army Base Realignment and Closure Division (BRAC) is overseeing the environmental cleanup of contamination at the site that resulted from the production of various defense items (such as explosives, pyrotechnics, illuminants, and rocket motors) beginning near the start of WWII, through the early 1990s. As a result of these efforts, approximately 7,000 acres of the 8,416-acre former installation have been found suitable for transfer to the U.S. Fish and Wildlife Service and are now being managed as the Caddo Lake National Wildlife Refuge. Great Raft Invasives Program The Great Raft Invasives Program (GRIP) is a project developed through a grant from the National Fish and Wildlife Foundation in 2012. Caddo Lake Institute initiated GRIP with the aim of helping individuals, organizations, and government entities to expand work on giant salvinia and other harmful invasive aquatic species beyond Caddo Lake. The six principal lakes in this area are Caddo and Lake O’ the Pines in Texas; and Cross, Wallace, Black Bayou, and Bistineau in Louisiana. Except for Lake O’ the Pines, these are called “raft lakes” because they were created by the huge log jam on the Red River that persisted for hundreds of years before removal efforts in the 19th Century (see the January 2020 edition of The Texas Water Source). Although naturally formed, the raft lakes are now maintained by spillways or dams. Although Lake O’ the Pines is not a naturally formed lake – it was created by the damming of Big Cypress Bayou – it is included in this program because of its proximity to the raft lakes and its relationship to Caddo Lake. Invasive aquatic plants and animals threatening any of the lakes of the Great Raft threaten all of these lakes. Their economic and recreational values are deeply intertwined. In particular, giant salvinia — because it is a rootless, floating plant — can easily move from one lake to another. Alligator weed, hydrilla, and water hyacinth are other non-native aquatic plants present in the lakes that can impair navigation, crowd out beneficial native plants, and spoil habitat for fish and other wildlife. Chinese tallow is an invasive wetlands tree that is rapidly displacing desirable native trees such as the mayhaw. Giant Salvinia on Lake O’ the Pines There has been an array of invasive vegetation with varying degrees of impacts present at Lake O’ the Pines Giant salvinia was discovered at the lake’s boat ramps in October 2012. Giant salvinia is a freefloating fern native to southeastern Brazil and northeastern Argentina. The species was brought into the U.S in 1995 through South Carolina, where it was a popular plant for water gardens and sold in the nursery trade. Giant salvinia varies in color from green to gold to brown with floating leaves in pairs about ½ inch wide and 1 inch long. It is somewhat similar in appearance to our native duckweed, but bigger. The upper portion of the leaf is covered in dense, white hairs joined at the leaf tip. The shape of the tip traps air, helping the plant be buoyant and float. Giant salvinia prefers tropical, subtropical, or warm temperatures and grows best in nutrient-rich, slow-moving waters such as ditches, canals, ponds, and lakes. Giant salvinia is aggressive in its ability to spread in lakes and waterways. It only takes a small fragment of salvinia to multiply vegetatively and produce mats, called a “sudd.” These mats of salvinia can double in size in less than a week and form layers that can be up to 3 feet thick in depth. The species has been reported in over a dozen water bodies and lakes within Texas. Typically, giant salvinia is spread to new waterbodies through boats and other recreational crafts transporting the invasive species, hence why the species was easily identified at the Lake O’ the Pines boat ramp. Giant salvinia mats cause problems in water bodies and damage aquatic ecosystems by:- preventing light from entering the water, thus stopping the growth of tiny organisms that form the base of the food chain for other aquatic organisms;
- outgrowing and replacing native plants that provide food and habitat for native animals and waterfowl;
- blocking out sunlight and reducing dissolved oxygen concentrations, which degrades water quality for fish and other aquatic animals;
- dying and sinking to the bottom, where the decomposition process uses up even more oxygen.;
- impeding the natural exchange of gases between the water and the atmosphere, which can lead to stagnation of the waterbody;
- Interfering with fishing, boating, and swimming. Ultimately, these processes can kill all plants, aquatic insects, and fish living below the mats. The mats also provide ideal conditions for mosquitoes to breed.
- Remove all plant material from your boat, trailer, tow vehicle, and gear, and place it in a trash receptacle BEFORE leaving any body of water.
- Eliminate water from all motors, jet drives, live wells, boat hulls, etc., before transporting it anywhere.
- Clean and dry anything that came in contact with the water before you enter another body of water.
- Do not release or put plants into a body of water unless they came out of that body of water.