the Miami Corporation fishing permit. This was necessary to reduce poaching, vandalism, theft, 

 and tampering with water control structures and to insure the success of the management program. 



Mineral Management 



Planning meetings, between LPWMA staff and oil company representatives, were held before 

 any mineral activities were initiated. Exploration drilling and development programs were modified 

 to be compatible with overall fish and wildlife management goals. 



From 1975 to 1987, nine well location canals were dredged on LPWMA. Continuous spoil 

 deposition was used to maintain the integrity of the semi-impoundment system. 



Mitigation, regulated and provided by governmental agencies was used to counter detrimental 

 environmental impacts. Levee construction, water control structure installation, and water control 

 structure maintenance were mitigation projects implemented on the area. Communication between 

 staff personnel, governmental agency personnel, and oil company representatives minimized adverse 

 environmental impacts associated with mineral development activities. 



RESULTS AND DISCUSSION 



Waterfowl Habitat Enhancement 



Water level and salinity management of semi-impounded marshes was very successful in 

 promoting the growth of high quality waterfowl food plants. Management success was due to 1) 

 sufficient drainage capacity of water control structures; 2) operational flexibility of water control 

 structures; 3) weekly monitoring of water level and salinities; 4) experienced staff personnel on call 

 24 hours/day, and; 5) a well planned tranasse system. 



An adverse effect of water level and salinity management practices at LPWMA was the 

 encroachment of emergent perennial plants into shallow open waters of fresh and intermediate 

 semi-impounded marshes. Similar effects have been observed in actively managed semi-impounded 

 marshes at Rockefeller Refuge (Wicker et al. 1983). In seasonally flooded upland impoundments 

 that were dewatered annually, dense growths of emergent perennials were found to invade open 

 water areas unless plant succession was set back (Linde 1969; Fredrickson and Taylor 1982). 



At LPWMA drawdowns and partial drawdowns allowed giant cutgrass, bullwhip, and jointgrass 

 to invade shallow pond bottoms. Encroachment by emergent perennials appeared to be facilitated 

 by very gradual reductions in water levels when pond bottoms remained saturated or damp for long 

 periods. Several consecutive years of partial drawdowns caused some ponds at LPWMA to fill with 

 cutgrass, bullwhip, and jointgrass. To make room for plants having greater waterfowl and wildlife 

 food value, attempts were made to eradicate these perennials. Introduction of brackish water used 

 to control water hyacinths was generally ineffective in controlling perennial plant encroachment. 

 When brackish waters (5-6 ppt) were held in Little Pecan Lake for 1-2 months, extensive stands 

 of cutgrass along the lake edge (and especially those growing in deeper water) were virtually 

 destroyed. Encroaching perennials were effectively controlled by treating with herbicides (2-4-D 

 or Rodeo) sprayed via helicopter. 



Jointgrass was the most troublesome emergent perennial. During periods of low water levels, 

 it would rapidly encroach upon shallow pond bottoms. Upon return to normal water levels, its 

 ability to tolerate shallow flooding allowed jointgrass to survive. Its dense network of roots, foliage, 



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