9442 - Laserfiche WebLink

Home Browse Search

more hatchery capacity now than believed necessary to ensure recovelY goals are met. Grow-out ponds are still a wildcard because of variable success. Floodplain wetlands can be used to supplement stocking targets, but cannot be relied on to meet targets due to unpredictable variables, like predation/competition. A risk exists that unmarked fish escaping to the river from wetlands may be misinterpreted as recruitment from stocked fish, rather than as stocked fish. All razomack sucker will be tagged to the best ability of the field personnel, but a certain number/percentage of unmarked fish would be acceptable. Razorback sucker stocked to meet stocking plans must be 300+ mm TL and PIT tagged. Initial minimum viable population (MVP) numbers of adults are expected to be met exclusively from stocked fish (i.e., stocking targets are designed to achieve MVP + average annual adult mortality buffer). But stocked fish must reproduce and their progeny recruit into the adult population to be considered a "self-sustaining" population. Ouray National Fish Hatchery's plan would place larvae in hatchery ponds in spring where they have higher survival and faster growth rates than inside under intensive culture. Then they would harvest 75-80 mm TL fish from ponds in fall and bring them inside for intensive culture up to 300 Imn TL. Some adult brood fish at 24-Road Hatchery are not spawned each year due to space limitations. Additional larvae could be placed in wetlands like StilTUp. Stirrup can be controlled (i.e., as razorback sucker are removed they can be tagged), whereas, Butch Craig connects to the river; therefore, nonnative predation/competition and escapement of unmarked razorback sucker larvae~juvenile cannot be controlled at Butch Craig. Bony tail Bony tail are considered adults at age-4+. Fish 200 mm fish (age 2+) will be stocked for 7 years (to achieve age-classes 4-10). Utah's plan buffers: 40% for age 4 and 30% for ages 5 and 6, based on expected differential age-class survival rates (0.6 vs. 0.7 for age 4 and age 5, respectively). New plan should use 30% across the board (like Colorado is using and comparable to razorback sucker). Two growing seasons yield 200 mm TL bony tail and 300 mm TL razorback sucker. There is some risk of bony tail hybridizing with hmnpback chub, but it is an acceptable risk given that they coexisted before. Region 2 of the Service has a large bony tail broodstock that could be available to the upper basin. We should ask for some bony tail from Region 2 to increase bony tail genetic diversity. Colorado pikeminnow When the 24-Road Hatchery is used for Colorado pikeminnow production, it loses razorback , sucker capacity; therefore, we should rely on the Mumma Hatchery for Colorado pikeminnow. Regions 2 and 6 of the Service should coordinate hatchery production. increasing Dexter's 10