Surgery has gone to the fishes at the Malheur National Wildlife Refuge
By Carla Burnside
for the Burns Times-Herald
Volunteers and staff at Malheur National Wildlife Refuge have been braving the blustery spring weather to capture and implant radio tags in invasive common carp.
Twenty radio tags purchased by the Oregon Wildlife Heritage Foundation (OWHF) were surgically implanted in carp at Boca Lake on the refuge over the last few weeks. OWHF donated $4,000 for the purchase of the radio tags, which will last for two years. The Harney County Veterinary Clinic donated sterile sutures to be used during the surgical procedures. Each radio tag has a unique frequency, which allows tracking of individual carp movements. The carp are captured alive and anesthetized, have the radios surgically implanted in them and then are revived and released back into the lake.
The radio telemetry project is part of a larger Harney Basin study that will analyze the impacts of invasive carp on area wetlands. Invasive carp are bottom feeders and their activities cause mud to rise in the water column.
When this happens sunlight cannot filter down through the water to stimulate plant growth. Waterfowl and other native fish depend on abundant plant growth in wetlands for feeding, nesting and spawning. When carp populations become too large they literally eat themselves out of house and home by eliminating all plant growth and they turn lush wetlands into wastelands. This not only impacts resident birds and fish, but it has a significant impact on migratory birds passing through the Harney Basin on their way to northern nesting grounds. A reduction in quality wetlands elsewhere in the Pacific Flyway means that Harney Basin wetlands are nationally important for migratory birds.
Boca Lake carp were chosen for the study to provide a controlled research environment to determine carp movements and to explore potential capture techniques to remove large numbers of fish. Twice a month for two years refuge fisheries biologists will track each of the tagged fish to identify their location. GPS coordinates will be used to build maps of population densities, to determine if the carp have seasonal preferences for congregating, where they feed at different times of the year and where they are spawning. These maps will then be used to decide on methods to decrease the number of carp in wetlands and possibly to eliminate carp.
Research elsewhere in the Great Basin indicates that carp often come together in large groups in the winter. If this also occurs in the Harney Basin, it would make it easier to capture large numbers of carp. Researchers involved in the project include Oregon Department of Fish and Wildlife, Ducks Unlimited, the University of Minnesota, the Natural Resource Conservation Service, Harney Basin Soil and Water Conservation District, Malheur Wildlife Associates and the U.S. Geological Survey.
The Oregon Wildlife Heritage Foundation has expressed interest in helping to raise private funds for carp control in the Harney Basin. The foundation was established in 1981 to receive money for and provide funding to beneficial fish, wildlife and habitat projects throughout Oregon. Over the last 30 years, the foundation has directed over $15 million dollars in monetary support to hundreds of fish and wildlife-related projects.