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Geology topics

Harold L. Kincaid

Publications and source records attributed to Harold L. Kincaid.

5 recordsLinked to original sources
USGS1993

Factors affecting feeding behavior and survival of juvenile lake trout in the Great Lakes

We explored the importance of experience with feeding on live prey, of cataracts, of strain, and of maternally transferred contaminants for the feeding rate and predator avoidance behavior of young lake trout Salvelinus namaycush . Hatchery-reared and feral juvenile lake trout were tested separately as predators on lake trout fry in tanks with artificial cobble reefs. Feral fish captured more prey per day and more prey per strike than did hatchery lake trout. The predatory performance of hatchery and feral fish did not improve significantly with experience. Feeding rates did not differ between lake trout with unilateral cataracts and normal-eyed fish, but significantly diminished for lake trout with bilateral cataracts. Neither strain nor contaminant background affected the ability of fry to feed or to avoid predators. Of the factors studied, previous experience with live food under natural conditions (i.e., the experience of feral fish) was the most important factor affecting feeding behavior of young lake trout.

Transactions of the American Fisheries Society↗
USGS1991

Growth and survival of stocked lake trout with nuclear cataracts in Lake Ontario

Four strains of yearling lake trout Salvelinus namaycush from the 1985 and 1986 year-classes at the Allegheny National Fish Hatchery were evaluated for nuclear cataracts prior to stocking in Lake Ontario in June 1986 and 1987. Lake trout recaptured by bottom trawling from April to August 1987 and 1988 were examined for cataracts. Cataract frequencies in three strains of yearling lake trout at stocking in 1986 and after 14 and 26 months in the lake were: Seneca Lake&ndash;35, 24, and 29%; Lake Ontario&ndash;32,24, and 42%; and Lake Superior&ndash;7,4, and 6%. Cataract frequencies for yearlings at stocking in 1987 and after 2 and 14 months were: Seneca Lake&ndash;51, 37, and 51 %; Lake Superior&ndash;7,12, and 12%; and Jenny Lake&ndash;46,13, and 36%. Cataract frequency was lower ( P < 0.05) at capture in three of the six groups recaptured in 1987 and in two of the six groups in 1988. Fish with cataracts in the 1987 recovery had survival ratios of 17&ndash;186% after 2 months in the lake and 48&ndash;67% after 14 months, compared with normal-eyed fish of the same strain. Nuclear cataract frequency was relatively stable after the first year of lake residency, when equilibrium was achieved between the increased mortality of cataract phenotypes and the rate of cataract development in normal-eyed phenotypes. Within groups, weight and length were not different between healthy fish and fish with cataracts. The absence of growth depression in fish with cataracts and the reduced survival rate suggested that faster growing fish were more susceptible to cataract formation.

North American Journal of Fisheries Management↗
USGS1989

Atlantic salmon brood stock management and breeding handbook

Anadromus runs of Atlantic salmon have been restored to the Connecticut, Merrimack, Pawcatuck, Penobscot, and St. Croix rivers in New England by the stocking of more than 8 million smolts since 1948. Fish-breeding methods have been developed that minimize inbreeding and domestication and enhance natural selection. Methods are available to advance the maturation of brood stock, control the sex of production lots and store gametes. Current hatchery practices emphasize the use of sea-run brood stock trapped upon return to the rivers and a limited number of captive brood stock and rejuvenated kelts. Fish are allowed to mature naturally, after which they are spawned and incubated artificially. Generally, 1-year smolts are produced, and excess fish are stocked as fry in headwater streams. Smolts are stocked during periods of rising water in spring. Self-release pools are planned that enable smolts to choose the emigration time. Culturists keep good records that permit evaluation of the performance of strains and the effects of breeding practices. As Atlantic salmon populations expand, culturists must use sound breeding methods that enhance biotic potential while maintaining genetic diversity and protecting unique gene pools.

Biological Report↗
USGS1983

Inbreeding in fish populations used for aquaculture

The theoretical causes of inbreeding depression are reviewed. Studies to measure depression at a series of inbreeding levels in rainbow trout populations using the method of inbred-outbred half-sib families are discussed. While the actual depression estimates varied widely between populations and inbreeding levels, significant levels of depression were found in many hatchery, field, and brood stock performance traits after only one generation of brother-sister mating. Especially susceptible to inbreeding depression, were measures of growth based upon attained fish weight at a given age in each test situation examined: 147 day weight (0.0 to 19.1%), 364 day weight (6.2 to 62.8%), weight after 6 months in fishing pond (−4.6 to 25.4%), weight after 12 months in fishing pond (13.0 to 29.1%), 2-year male weight (11.3 to 55.3%), and 2-year female weight (10.2 to 57.0%). Other hatchery performance traits that showed inbreeding depression were: egg hatch-ability (−0.2 to 53.1%), fry survival (0.4 to 8.2%), feed conversion efficiency (5.0 to 9.0%), fish length at 2-years of age (4.7 to 36.9%), and egg mass produced at 2-years (12.1 to 57.0%). Field performance traits that yielded inbreeding depression were percent recovery of fish stocked (−2.5 to 41.1%) and biomass index (16.2 to 47.7%). Literature on the effects of inbreeding in fish populations is reviewed and the breeding approaches for controlling the rate of inbreeding accumulation in brood stock populations are outlined and discussed.

Aquaculture↗