Bigger Fish to Fry: Environmental Management works to improve fish habitat giving fishers something to reel in Published April 27, 2007 By Amanda Creel 78th ABW/PA Robins AFB, Ga. -- Next time you cast out your fishing rod at Scout Lake you might find yourself reeling in a Christmas tree branch. Such a catch would be the result of efforts at Robins to promote a healthy habitat for fish in the base lakes. The Christmas trees, which are part of the base recycling program, are anchored about 30 feet beyond the pier to provide cover for the fish and to attract fish to casting range, said Bob Sargent, natural resources manager. The goal of the program is to assure that Scout Lake provides the optimal environment for the fish inhabiting the lake. "We are trying to make Scout Lake, a better lake and environment for the fish," Mr. Sargent said. "Because the lake is man made on high ground, it is very poor in nutrients." The lack of nutrients creates the need for the lake to be fertilized replacing needed nutrients like nitrogen and phosphorus. Wednesday members of the Environmental Management team spent their afternoon trolling the lake and dispensing lime. Adding lime not only increases the hardness of the water, it also increases the pH level, which helps create the best possible conditions for fertilizing. The lime helps the water reach the required calcium carbonate level or hardness for fertilization to begin. "Not only does the water have to be at the right level of hardness, the temperature of the water has to be at least 65 degrees," Mr. Sargent said. "If we don't have the hardness in the right range the nutrients just get eaten up by the mud." This is why the environmental management team was able to start fertilizing earlier this month. "We take samples each week and then keep a database and fertilize based on the results," said Joel Burke, office manager for the URS Corporation in Warner Robins who helped add lime to the lake. The motor boat used by the team may have taken many members of the Robins community by surprise because normally motorized boats are prohibited on the lake. "We allow it for this because of the work they're doing and because the prop on the motor helps mix the solution," Mr. Sargent said. By fertilizing the lake, the team is promoting the growth of phytoplankton, which is at the bottom of the lake's food chain. By improving the phytoplankton in the lake, the rest of the lake's food chain should follow suit. "Even though they are not visible to the naked eye, you can see if there is a healthy amount of phytoplankton because it changes the water color and tints it green," Mr. Sargent said. One of the signs the lake is in trouble is the absence of bass fry. The team noticed the absence of bass fry when the team examined the lake with a Seine Net last summer. The Seine Net is used to sample the lake's population. It measures 30 feet by four feet and one person stands on the edge of the water holding one end of the net, while another goes out into the water and folds the net around. Then together the pair closes the net much like fastening a purse and places the fish on the bank. "We found hundreds and hundreds of blue gill fish and no bass fry," Mr. Sargent said. He added the absence of bass fry indicates the bass aren't reproducing. Because of the blue gill overpopulation in the lake, the blue gills themselves also suffer, showing signs of stunted growth, some measuring only two to three inches. A good balance of prey to predator fish would be three to six pounds of prey fish to every one pound of predator fish, Mr. Sargent said. "Right now, we are way out of balance," he added. He said members of the team also use the experience of those who fish at the lake to discover which populations are flourishing and which ones are waning. In June, team members will be stocking the lake with bass ranging from 12 to 14 inches, which means the fish are already large enough to reproduce, Mr. Sargent said. Though the lake will have some prize bass to reel in, Mr. Sargent said until the lake's balance of predator and prey fish is harmonized the bass will be catch and release. "The reason is if we let them keep the prize bass then we will never fix the overpopulated prey species," Mr. Sargent said. However, Mr. Sargent and Mr. Burke said, they would love for fisherman to snag as many blue gill and crappies as they can from the lake. Mr Sargent said providing the fishing services on base is a team effort between Environmental Management and Services. "It's a team effort. It always has been. They provide the information and licenses and we make the rules and regulations and provide the on-site management," he said. Sharron Wilhelm, a recreational aide with outdoor recreation said the partnership between Environmental Management and Services provides a great opportunity for base fishers to get out and enjoy the lakes. Other lakes on base are part of the program as well, but each lake is managed based on its individual needs. Duck Lake is healthy in nutrients and doesn't have the prey overpopulation that exists at Scout Lake. While Luna Lake, also struggles with a lack of nutrients, the Environmental Management team has taken another approach to managing its population. "Instead of having an unhealthy and unbalanced lake, we decided to make it a catfish pond," Mr. Sargent said. He said the lake is stocked with good size catfish each fall ranging in size from 8 to 11 inches, not just fish fingerlings. Originally the team attempted to fertilize Luna Lake as well, but because the lake is elevated and the basin leaks, the fertilizer simply leaked through, accomplishing little. What to know Anyone interested in fishing in the base lakes can contact outdoor recreation at 926-4001 or stop by the rental center. To receive a base fishing license you have to be affiliated with the base and have a valid Georgia fishing license.