The Higgins' eye pearly mussel is a freshwater clam that is found only in the Mississippi River, the St. Croix River in Wisconsin, the Wisconsin River and the Rock River in Illinois below the first dam. It was listed as an endangered species on June 24, 1976. It was never abundant and where it is found it only comprises approximately 0.5% of the mussel population. At the time the original recovery plan was written in 1982, data indicated that this species had undergone a 53% decrease in its known range.

Recovery Team Members

In 1994, the Higgins' Eye Recovery Team was reconstituted and reconvened to gather data and reassess the current distribution and status of the species, and to revise the recovery plan as necessary.

Recovery Team's Activities

• Conducted site characterizations of 10 or more mussel beds where Higgins' eye is known to occur, including several essential and secondary habitats that had not been surveyed for over 10 years. Dr. Andrew Miller, Dr. Daniel Hornbach, Mike Davis and David Heath have completed these characterizations.
  
• Conducted a literature search and synthesis of all published, unpublished and gray literature since the original recovery plan was written in 1982. Dr. Edward Cawley, Loras College, Dubuque, IA compled this task.
  
• Write a Revised Recovery Plan to incorporate new data and, potentially, to revise the recovery criteria. Dr. Daniel Hornbach completed this task.

Schedule

• August, 1998 - technical/agency draft Revised Recovery Plan completed and sent out for public review. Comments have been received and are being evaluated by the Team
  
• Fall, 2000 - completion of a final Revised Recovery Plan

Recovery Criteria (from the 2000 Revised Recovery Plan)

• L higginsi may be considered for reclassification to threatened when at least 5 of the essential habitat areas contain reproducing, self-sustaining populations.
  
• L. higginsi may be considered for delisting when at least 5 of the essential habitat areas contain reproducing, self-sustaining populations of sufficient security to assure long term viability to the species.
  

Essential Habitats

The Team has identified ten mussel beds that it determined to be essential to the survival of the species. These are NOT designated critical habitats. The essential habitats are as follows: