SUZANNE J. DILWORTH, ELIZABETH H. SMITH, Center Coastal Studies, Texas A&M University, Corpus Christi, Texas, USA

STEWART JACKS, U. S. Fish and Wildlife Service, Corpus Christi Fishery Resources Office, Corpus Christi, Texas, USA

In 1969, a variable-crest weir was constructed on the Brazoria National Wildlife Refuge (BNWR), Texas. The function of the weir is to retain water in the marsh during winter low tides to maintain vegetation and critical bird habitat. However, fishes are negatively impacted by the impedance of the weir on egress and ingress to crucial nursery habitats. Two study sites, one managed and one unmanaged, located on Salt Lake in the BNWR were selected to determine the effects of the weir on fish movements. Light traps and bag seines were utilized twice a month from July 1995 to July 1996 to sample larval and juveniles fishes and commercially-important crustaceans. A total of 51,717 individuals were collected representing 31 families and 52 species. The dominant organisms collected were Brevoortia patronus with 13,780 individuals and Penaeus setiferus with 12,980 individuals. Water quality measurements were also taken at both sites. Results from this study will be used to provide management strategies for coastal National Wildlife Refuges in Texas.