Premium
Population Dynamics of Hatchery‐Reared Landlocked Salmon, Salmo salar, at Schoodic Lake, Maine
Author(s) -
Havey Keith A.,
Andrews Philip S.
Publication year - 1973
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1973)102<728:pdohls>2.0.co;2
Subject(s) - salmo , fishing , fishery , age groups , population , biology , hatchery , zoology , age structure , fish <actinopterygii> , demography , sociology
Landlocked salmon, Salmo salar, were introduced into Schoodic Lake, Washington County, Maine in 1960. From 1963–70 we studied nine groups of stocked salmon to obtain information on survival, standing crops, the salmon sport fishery, and population density‐catch relationships. Average survival from age I+ to age II+ (four groups) was 47.9%. Average survival from age II+ to age III+ (five groups) was 53.1%. Average survival from age III+ to age IV+ (three groups) was 23.9%. Average survival from age IV+ to age V+ (four groups) was 14.2%. Few salmon survived beyond age V+. Annual survival, excluding fishing mortality, for four groups of young salmon ranged from 26.4% to 61.6%. Survival from planting to 6 months at large for one group was 72.6%. Annual survival after death from all causes ranged from 17.6% for one group of salmon from age III+ to age IV+ to 73.1% for one group of salmon from age II+ to age III+. Numerical annual standing crops from 1964–69 computed by the Petersen method ranged from 4.0 ± 1.0 to 13.8 ± 2.0 fish per ha. Weight standing crops from 1964–69 ranged from 2.5 ± 0.4 to 3.4 ± 1.0 kg per ha. Catch per angler hour by sport fishing ranged from 0.036 in 1969 to 0.229 in 1967. Annual mean number of salmon checked was 164. Salmon creeled averaged 38.6 ± 0.5 cm in total length and 0.5 ± 0.04 kg in weight. Based on an estimated 75.0% census, mean numerical yield was 1.4 fish per ha. Mean weight yield was 0.7 kg per ha. Of 12,107 salmon stocked, 8.6% were subsequently checked in anglerˈs creels. Salmon stocked at age I+, age I, and age 0+ yielded returns of 14.3%, 8.9% and 5.4% respectively. Mean effort per ha per year was 6.9 angler hours. There is a linear relationship (1964–69 data) between population density expressed as numbers per ha and numbers per ha captured by fall trap netting. There is also a linear relationship between population density expressed as numbers per ha and catch per angler hour of all salmon the following fishing season. Indications are that management of small lakes such as Schoodic for salmon can be a fruitful management practice.