Factors Influencing Growth and Body Condition of Alewives in Connecticut Lakes

ABSTRACT

Alewives were collected by nighttime gill netting during summer 1999 from 12 Connecticut lakes that support landlocked populations to determine relationships between population characteristics and physicochemical lake variables. Mean catch-per-unit-effort (CPUE) ranged from 0.2 to 16.4 age-1 and older alewives per net hour. Maximum ages of alewives among lakes ranged from two to five years, and mean back-calculated length-at-age-1, used to index growth rate, ranged from 78 to 146 mm. Mean back-calculated length-at-age-1 was positively correlated with mean relative condition factor (K_n), watershed area:lake surface area ratio, watershed area:lake volume ratio, lake surface area:lake volume ratio, conductivity, total nitrogen, alkalinity, calcium, magnesium, and chlorophyll a, and negatively correlated with retention time, maximum lake depth, mean lake depth, and transparency. Mean K_n ranged from 0.93 to 1.23 and was positively correlated with mean back-calculated length-at-age-1, watershed area:lake volume ratio, lake surface area:lake volume ratio, total nitrogen, chlorophyll a, and potassium, and negatively correlated with maximum lake depth and transparency. Growth and K_n of alewives were highest in shallow, productive lakes with low transparencies. CPUE was not related to growth rate or to any physicochemical lake variable.