Purpose of Document
The Best Management Practices (BMPs) described in this document are designed to minimize and avoid disturbance to at-risk and protected mussel and turtle species in East Texas and Western Louisiana. These BMPs may also benefit other species that co-occur with the Covered Species that could be present during maintenance and operations activities.
Covered Species and Ecological Profiles
Native freshwater mussels are an inconspicuous group of organisms that play a vital role within the aquatic environment as filter feeders. They remove algae, bacteria and other material from the water column, improving the water quality within their environment. Most mussels live their lives in the bottom of flowing waters, usually in areas with stable substrate (gravel, cobble or boulder). Certain species have adapted to be found in backwaters, oxbows, lakes and in sandier/silt filled environments. Currently, 27 different species of native mussel can be found within the Sabine River Basin. For the purposes of this document, all native mussel species will be treated the same under these BMPs. However, the following species are protected in Texas and are under review by the US Fish and Wildlife Service (USFWS) for listing under the Endangered Species Act (ESA): Texas Pigtoe (Fusconaia askewi), Texas Heelsplitter (Potamilus amphichaenus), Louisiana Pigtoe (Pleurobema riddellii), and Sandbank Pocketbook (Lampsilis satura).
The Alligator Snapping Turtle (Macrochelys temminckii) is the largest freshwater turtle in North America, native to river systems that flow into the Gulf of Mexico. Alligator Snapping Turtles are currently protected in Texas and the species status is under review by the USFWS for listing under the Endangered Species Act (ESA). Alligator Snapping Turtles are omnivores and the only turtle that has a predatory lure (worm-like appendage on the tongue) that acts as bait to attract fish. They also eat crayfish, smaller turtles, insects, nutria, snakes, birds, and vegetation. Alligator Snapping Turtles are generally found in slow-moving water and prefer underwater structures such as submerged trees and root systems. The species tends to use shallower water in early summer and deeper depths in late summer and mid-winter. This behavior is thought to help Alligator Snapping Turtles thermoregulate.
The Western Chicken Turtle is a small to medium-sized freshwater turtle that is not State listed by Texas or Louisiana but is under review by the USFWS for listing under the ESA. They are found in ephemeral or semi-aquatic areas that contain slow-moving and shallow water, such as ponds, lakes, streams, and swamps. In Texas, Western Chicken Turtles usually live in ephemeral wetlands from February to July, then migrate to upland sites where they burrow underground into soft soil to escape hot or dry conditions for the remainder of summer, fall, and winter.
Best Management Practices
Sabine River Authority operations often require staff to work in riparian areas where the Covered Species may be found. These Best Management Practices are designed to minimize any disturbance of the Covered Species while working in and near their habitat:
- Ensure that projects are evaluated for compliance with Texas Parks and Wildlife Department (TPWD) Guidelines for Aquatic Resource Relocation Plans for Fish and Shellfish, Including Freshwater Mussels (ARRP).
- Employees and contractors should be provided with educational materials on the covered species. The contents of these materials should focus on general identification, habitat identification, and avoidance measures for these covered species.
- Equipment and materials should be staged outside of riparian areas when feasible and only brought into the area when necessary to complete the goal/task.
- Vehicles and equipment used regularly for work within the riparian environment should be routinely checked for fluid leaks.
- Exclusion barriers, temporary coffer dams, and silt fencing should be constructed when required by USFWS, TPWD, or other agencies. Barriers should not impede flow when possible, should be made of nontoxic materials, and should be checked daily. Avoid removing habitat features of possible.
- Any vehicles or machinery operating within waterways should comply with all State laws and/or State/Federal permit regulations.
- Any Covered Species spotted by personnel within or near the project area should be immediately reported to SRA biologists. If an Alligator Snapping Turtle is sighted, take a photo, only if a photo can be taken without harassing the animal, and report the sighting to SRA biologists.
- Avoid removing or destroying unique aquatic habitat features (downed trees, root snags, etc.) unless necessary.
- Upon completion of the project, restore aquatic habitat features that were removed when practical.
Threats within the Sabine
Threats to these Covered Species may include; altered hydrology, degraded water quality, modification, loss, or fragmentation of habitat, and barriers to dispersal. All these factors can and have impacted the Covered Species in varying degrees within the Sabine Basin. Freshwater mussels are the most endangered species group in the United States, with multiple species either listed or currently under consideration for Threatened or Endangered Species Protections. Alligator Snapping Turtle, along with the threats above, are commonly poached for their meat, shell or to be sold in the pet trade.
Identification
Louisiana Pigtoe freshwater mussels.
Texas Heelsplitter freshwater mussel.
Common freshwater mussels in the Sabine River Basin.
