GBRA Executive Manager of Environmental Science Nathan Pence talks freshwater mussel protection in the Guadalupe River basin, breaking down the U.S. Fish & Wildlife Service’s most recent protection proposal.
In alignment with our mission to conserve, protect and enhance our ecosystem, our Environmental Science team works collaboratively with like-minded partners – including Texas Parks & Wildlife and U.S. Fish & Wildlife Service – to monitor the health and vitality of aquatic species throughout the Guadalupe River Basin. For the past several years, our Environmental team – the Guad Squad – has conducted freshwater mussel sampling events to establish species distribution. In other words, our field team goes out to various locations within our basin to find and identify different species of freshwater mussels and make note of the features of their environments. Identifying the characteristics of their habitat allows us to estimate potential habitats in other similar locations where we may not be able to collect data on the presence or absence of the mussel population. Our fieldwork on these freshwater mussels has also included collaboration on research projects to determine life history characteristics, including factors such as the number, size and sex ratio of offspring, timing of reproduction, age and size at maturity, growth patterns, and life span. As a data-gathering partner for U.S. Fish & Wildlife Service (USFWS), we provided them with data from sampling events to assist with their Species Status Assessment of central Texas freshwater mussels. The Species Status Assessment Framework is an analytical approach developed by USFWS to deliver foundational science in order to determine whether a species warrants federal protection under the Endangered Species Act (ESA).
Based on those assessments and others, U.S. Fish & Wildlife Service (FWS) announced today a proposal to protect three freshwater mussel species from the Guadalupe River under the ESA – the Guadalupe orb, Guadalupe fatmucket and false spike – and designated critical habitat for each. The Texas pimpleback and the Texas fatmucket species were also proposed for protection, but are not currently known to exist within our basin.
Earlier this year, GBRA initiated the development of a basin-wide Habitat Conservation Plan (HCP) for the Guadalupe River, in part anticipating the listing of these mussel species. Through this HCP we will work to find the right balance that provides for various uses of the Guadalupe River, thus creating stability and sustainability of water supply and other services, under the ESA, while preserving and benefiting aquatic species too. In developing this HCP, we will continue to collaborate with state and federal authorities, including FWS, along with stakeholders in the basin to gather information on these and other rare species. Efforts to protect these freshwater mussels, as well as other endangered species in the Guadalupe Basin, will ultimately result in healthier rivers and streams, benefitting the communities, industries and species that depend upon them.
The three freshwater mussel species found in the Guadalupe River proposed for listing as federally endangered are the Guadalupe fatmucket (Lampsilis bergmanni), Guadalupe orb (Cyclonaias necki), and false spike (Fusconaia mitchelli).
- The Guadalupe fatmucket occurs in the North Fork Guadalupe and Guadalupe rivers as well as Johnson Creek. Very few individuals of this species have been found in recent years, and the rivers in which it occurs are subject to low flows.
- The Guadalupe orb occurs in the South Fork Guadalupe, Guadalupe, and San Marcos rivers. Only two populations remain of this species, and one does not appear to be reproducing as all individuals that have been found in recent years are old.
- The false spike occurs in portions of the Brazos, Colorado, and Guadalupe River basins. In the Guadalupe basin, the false spike occurs in the Guadalupe and San Marcos rivers. All populations of this species are small and isolated, and most populations are subject to declining flows.
The proposal also recommends the designation of portions of the Guadalupe river basin as critical habitat. Critical habitat identifies geographic areas occupied by the species, in this case the freshwater mussels, at the time the species is listed for protection that contain the physical or biological features essential to the species’ conservation. Designating critical habitat is a tool used to identify areas that are important to the recovery of a species. It also notifies federal agencies of areas that must be given special consideration when they are planning, implementing or funding activities. A critical habitat designation requires federal agencies to consult with FWS on any of their actions that may affect designated critical habitat. It is important to note that critical habitat designation has no effect when a federal agency is not involved. It imposes no requirements on state or private actions on state or private lands when no federal funding, permits, or approvals are required. For example, a private landowner undertaking a project that involves no federal funding or permit has no additional responsibilities if the property falls within critical habitat boundaries.
More information about the proposed listing and designation is available here: Questions and Answers: Listing and Critical Habitat Proposal for Six Central Texas Mussels (fws.gov). As part of its listing proposal for these freshwater mussel species, FWS has opened a 60-day public comment period and will host virtual informational meetings followed by public hearings on Tuesday, Sept. 14 and Thursday, Sept. 16. Those interested should visit [Southwest Region – Austin, TX ES Field Office (fws.gov)] for more information.