Accession Number : ADA182443

Title :   Aquatic Plant Control Research Program: Evaluation of the Diver-Operated Dredge and Bottom-Covering Materials for Control of Hydrilla in the Potomac River.

Descriptive Note : Final rept.,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS ENVIRONMENTAL LAB

Personal Author(s) : Killgore,K. J.

Report Date : MAY 1987

Pagination or Media Count : 18

Abstract : Estimated costs is $17,500/acre. In addition to the dredge being extremely time-consuming, rapid reinfestation of the dredged plots occurred from remaining tubers and from fragments drifting in from adjacent areas. The dredge is not recommended as a control measure. Two types of bottom-covering materials, Dartek and Texel, were placed in boat lanes and boat slips. The time expended to prepare and install Dartek and Texel in a 9,000-sq-ft boat lane was 6.6 and 1.1 hr, respectively. Sections of Dartek must be taped together to obtain the desired dimensions, increasing preparation time of this material, while taping is not necessary for Texel. Estimated cost per acre is $11,745 for Dartek and $10,875 for Texel. For boat slips the average rate of installation for Dartek and Texel was 9 to 13 min and 11 to 12 min, respectively. Hydrilla grew through the slits and seams of Dartek, resulting in plant height measurements similar to the control 20 days after installation. Furthermore, during low tide, boat propellers would come in contact with the Dartek and dislodge the material from the achoring system. Sediment settled on the Texel and prevented benthic gases from escaping, causing the material to 'balloon' and interfere with boat navigation. Consequently, both materials were removed from the boat lanes and slips 1 month following installation. Keywords: Aquatic weeds; Marine biology; Weed control.

Descriptors :   *AQUATIC WEEDS, *WEED CONTROL, BOATS, NAVIGATION, CONTROL, COST ESTIMATES, TIDES, MATERIALS, BENTHONIC ZONES, GASES, DRIFT, FRAGMENTS, MARINE BIOLOGY, POTOMAC RIVER, MARINE BIOLOGY, PREPARATION, TIME, SEDIMENTS, RATES

Subject Categories : Biological Oceanography
      Biology

Distribution Statement : APPROVED FOR PUBLIC RELEASE