weired than unweired area on nearby Marsh Island. Most of their other distributions seemed to 

 agree with ours, especially for the menhaden, which were more common in unvegetated areas and 

 more prevalent where weirs are absent. 



Of the incidental species, most appeared in Fearman, but Bob's contained more than Toms. 

 This pattern may not be related to the weir or spatial arrangements, since two of the species, 

 pipefish and rainwater killifish, prefer submerged vegetation present only in Bob's. Overall, in 

 comparing the two small lakes, we found no statistically significant differences between catch rates 

 or number of species, but we did find some individual species differences that cannot be tested with 

 data from only 1 year. 



CONCLUSIONS 



While it is too early in the study to draw any conclusions, a number of facts suggest that fruitful, 

 more substantiated conclusions will ultimately be available from such a study. 



Differences among the three lakes could be caused by several factors: 



(1) Fearman is closer to the supply of larvae for most species and should have a greater 

 number of species than the other two sampling areas. 



(2) Bob's has a weir which keeps water levels more stable and never allows exposed bottom, 

 resulting in larger amounts of detritus and development of submerged vegetation. The weir 

 may restrict migrations. Toms goes dry many times during the year and must have a 

 shallower average depth, which could be preferred by certain species like spot and red 

 drum. 



(3) Toms is farthest from the source of larvae, is a smaller lake, and is reachable only through 

 a long winding bayou. It is closest to the large freshwater source of the marsh to the west. 



(4) Due to fortuitous events, blocks of water with larvae of certain species may enter either 

 Bob's or Toms. Bob's, located on the north side of Fearman, may be favored during 

 southerly winds, while the reverse is true on the south shore, although northerly winds 

 cause water levels to drop everywhere. Also, tidal currents, even when wind driven, seem 

 to fill all areas. If these fortuitous events are the main cause of differences, then the 

 observed differences will not be consistent from year to year. 



At this point there are no clear-cut statistically significant differences between the areas, and 

 possible similarities outweigh the differences between the weired and unweired areas, as well as 

 the common area of Fearman Lake. However, certain species may be somewhat selected more 

 for one area or the other. At present the data suggest that if the weir is the cause of the 

 observed distributions, weirs favor grass shrimp, juvenile crabs, and more minor species, but 

 discriminate against menhaden, spot, and perhaps other species tied to very shallow water. At 

 this point the data are not conclusive but are very intriguing. 



ACKNOWLEDGMENTS 



This study was funded by a contract with the Refuge Division of the Louisiana Department of 

 Wildlife and Fisheries. Thanks to Johnny Tarver and Greg Linscombe for their support and 



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