Presenter: Wendy Gordon

Commission Agenda Item No. 7
Listing of Certain Mussel Species as State-Threatened
November 5, 2009

I. Executive Summary: This item seeks adoption of proposed rules that add 15 species of freshwater mussels to the state's list of threatened species and clarify that threatened mussel species may not be taken under any circumstances.

II. Discussion: Under Parks and Wildlife Code, Chapter 67, the Commission is required to establish any limits on the taking, possession, propagation, transportation, importation, exportation, sale, or offering for sale of nongame fish or wildlife that the department considers necessary to manage the species. Chapter 67 defines nongame wildlife as fish and wildlife that are not classified as game animals, game birds, game fish, fur-bearing animals, alligators, native shrimp, oysters, or endangered species. Under the authority of Chapter 67, the department has promulgated rules designating certain species of fish and wildlife as threatened, which is defined by rule as "likely to become endangered in the future." By rule, a threatened species may not be taken, possessed, propagated, transported, imported, exported, sold, or offered for sale.

Freshwater mussels (unionids) are an important component of healthy aquatic ecosystems, both as a food source for many other aquatic and terrestrial organisms, and as an important indicator species. In early life stages, mussels are food sources for a variety of aquatic insects, small fishes, and water birds; as they mature they become significant food sources for larger fishes, waterfowl, and terrestrial animals. Protection of this resource preserves and enhances the hunting, fishing, and outdoor recreation opportunities that are a part of Texas heritage.

Freshwater mussel populations have declined throughout North America. They are sensitive to disturbance because they are relatively immobile organisms, sometimes staying in a single spot for their entire lives. Mussels are very long-lived animals, some living over 100 years, and are very slow-growing. They have a complex life cycle that is easily disrupted, causing reproductive failure. Habitat alteration and loss, illegal and over harvesting, and competition from introduced species are some of the factors in their decline.

Nationwide, more species of freshwater mussels are listed as threatened and endangered than any other group of animals. Of the nearly 300 species known to have lived in the U.S., 18 are believed to be extinct, and 60 are currently listed as federally endangered or threatened, including one species occurring in Texas (the Ouachita rock-pocketbook mussel). Texas is home to more than 50 species of freshwater mussels.

Staff has identified 15 species of freshwater mussels that meet the department's criteria for listing as threatened species by virtue of being habitat-limited, sensitive to water quality degradation, and known to occur only in specific, limited geographical areas. Staff recommends that the 15 species be placed on the list of threatened species in order to afford them further protection.

Staff received permission at the August 2009 meeting of the Regulations Committee to publish the proposed amendments in the Texas Register for public comment. The proposed regulations (located at Exhibit A) appeared in the October 2, 2009, issue of the Texas Register (34 TexReg 6832, 6833). A summary of public comment will be available at the time of the meeting.

III. Recommendation: Staff recommends that the Texas Parks and Wildlife Commission adopt the following motion:

"The Texas Parks and Wildlife Commission adopts amendments to 31 TAC §§65.175, concerning Threatened Species, and §57.157, concerning Mussels and Clams, with changes as necessary to the proposed text (located at Exhibits A and B, respectively) as published in the October 2, 2009, issue of the Texas Register (34 TexReg 6832, 6833)."

Attachments - 2

  1. Exhibit A - Proposed Amendment to Threatened Species Rules
  2. Exhibit B - Proposed Amendment to Mussel Rules