Eastern Wildlife Damage Control Conferences


Date of this Version

October 1993


A floating rope system consisting of lengths of 9.5 mm (3/8 in) yellow polyethylene rope and foam floats was evaluated for reducing double-crested cormorant (Phalacrocorax auritus) depredation on farm raised channel catfish (Ictalurus punctatus) Mississippi. The ropes were placed at 15-17 m intervals across 2 ponds (4.6 and 6.0 ha) perpendicular to the prevailing winds. Helium-filled balloons were used in an attempt to enhance the effect of the ropes. Cormorant numbers entering both test ponds were recorded during pretreatment, treatment, and posttreatment periods. The floating ropes were effective in reducing cormorant numbers on ponds (by at least 95%) during the 3 to 8-week treatment periods and may be more practical to use on large (>2 ha) ponds than overhead wire grid systems.