Restoration of Anadromous Alewives at Long Pond, Maine
Maine, restoration, Alosa pseudoharengus, alewife, stocking, body length, mortality
Journal or Book Title
Transactions of the American Fisheries Society
From 1950 through 1953, 1,403 to 1,793 near-ripe anadromous alewives, Alosa pseudoharengus, were stocked annually at Long Pond, Hancock County, Maine, to restore an alewife run in the Long Pond drainage. The four stockings produced alewife runs of approximately 11,000 to 51,000 fish in a 3- to 5-year period following each stocking. Later runs (1958-59) produced by progeny of stocked fish were similar to those produced by stocking. There was little relationship between escapement and numbers of progeny 3 to 5 years later. Runs were of age-groups III-VIII but were dominated by age-groups IV-VI. Age-group III appeared in two of the six annual runs and in only one run in significant numbers. Fish of the large 1951 year class appeared in all runs from 1954 through 1959. Older alewives migrated early, but males and females migrated in about equal proportion throughout the run. Body and scale growth was essentially isometric above a body length of about 3.0 inches. Female alewives were significantly larger than males in the Long Pond drainage at ages IV, V, and VI. Fish of given age groups did not fluctuate significantly in size from year to year. Ultimate attainable lengths of male and female alewives determined by the method of Walford were 13.1 and 14.0 inches respectively. The observed sex ratio was 1.28 males to 1.00 female. Sixty-six and one-half percent of age-group V in the run had spawned once and 63.4 percent of age-group VI, twice. No fish of age-group III but all of age-group VI had spawned previously. Annual mortalities from age-groups V to VI and from VI to VII were calculated as 78.6 and 74.4 percent, respectively. The post-spawning mortality in Long Pond was 41 percent for age groups combined.