The Louisiana Department of Wildlife and Fisheries (LDWF) Aquatic Plant Control Program made substantial progress in the treatment of hydrilla on Black Lake during the summer of 2008.
LDWF’s Inland Fisheries Division, in cooperation with the Northwest Louisiana Fish and Game Preserve Commission, treated 3,300 acres of invasive aquatic weeds on the Natchitoches Parish water body in June and August.
During the course of the summer spraying efforts, LDWF utilized 20 technicians to disperse 15,480 pounds of herbicide on the 3,300 surface acres of hydrilla above and below the LA Hwy. 9 bridge. The total herbicide treatment included a second spraying of 600 acres below the LA Hwy. 9 bridge.
LDWF expended $400,000 for herbicide at Black Lake, made possible by increased allocations for herbicide application in two successive fiscal years. In the 2008-09 fiscal year, the Aquatic Plant Control Program was bolstered by an additional $2 million allocated by the Jindal administration, raising the program budget to $8.3 million for the current fiscal year.
“The department would not be able to conduct such large scale aquatic weed control projects without the added funding,” said LDWF Inland Fisheries Division Administrator Gary Tilyou.
LDWF utilized six-two man teams in boats that used mechanical blowers to distribute the herbicide. A work barge from Toledo Bend was used to transport the herbicide to a central location in the lake and became a central distribution point for the boats.
“I’m impressed with how effective these herbicide applications have been in controlling this invasive pest,” said Northwest Louisiana Fish and Game Preserve Commission Member Junior Brown.
Following the applications, LDWF conducted water tests at intervals to ensure the level of herbicide in the water was adequate to kill the hydrilla. The applications benefited from dry weather and low water levels that created a low water flow in the areas treated, which allowed the herbicide to remain in the treatment area.
“Follow up surveys of treated areas indicate that the vast majority of the hydrilla has been killed,” said Ricky Moses, LDWF Inland Fisheries District 3 manager. “During my treatment evaluation, I was able to access places on the lake I’ve never been to in my nine years of working in the area.”
Hydrilla was first found in Black Lake, a 13,800-acre water body, in the early 1990s and was causing numerous problems for boaters and fishermen.