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Diel migrations of a zooplanktivorous fish ( Menidia beryllina ) in relation to the distribution of its prey in a large eutrophic lake 1
Author(s) -
Wurtsbaugh Wayne,
Li Hiram
Publication year - 1985
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1985.30.3.0565
Subject(s) - diel vertical migration , littoral zone , zooplankton , predation , planktivore , fishery , forage fish , environmental science , shore , oceanography , biomanipulation , piscivore , foraging , ecology , eutrophication , biology , phytoplankton , geology , predator , nutrient
Diel changes in the distribution of the tidewater silverside ( Menidia beryllina ) and its prey were measured in Clear Lake, California, a large, shallow, eutrophic lake. Zooplankton prey densities were low in the littoral zone, but increased rapidly to near peak abundances 50–200 m from shore. Gill netting, trawling, and visual observations showed that tidewater silversides migrated both horizontally and vertically to feed in areas of high zooplankton abundance. At night the fish concentrated near shore and did not feed. At dawn (8 × 10 8 −2 × 10 10 photons cm −2 nm −1 s −1 ) the fish migrated lakeward at least 50–1,000 m, and littoral abundance decreased from more than 100 m −2 to only 0.1 m −2 . The migration preceded the initiation of feeding by 30–60 min. After feeding 2–4 h, the fish returned to the littoral zone and swam rapidly (6–11 body lengths s −1 ) parallel to shore in narrow, continuous schools until resting aggregations formed. The fish returned to shore before they were satiated, perhaps to balance predation losses in offshore areas against foraging gains. A second period of offshore activity and feeding occurred in the afternoon and evening.