Premium
Influence of Reservoir Productivity and Juvenile Density on First‐Year Growth of Gizzard Shad
Author(s) -
Michaletz Paul H.
Publication year - 1999
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8675(1999)019<0842:iorpaj>2.0.co;2
Subject(s) - dorosoma , gizzard shad , juvenile , productivity , biology , gizzard , fishery , predation , ecology , fish <actinopterygii> , macroeconomics , economics
First‐year growth of gizzard shad Dorosoma cepedianum varies widely among Missouri reservoirs. Sport fishes tend to grow slowly in reservoirs where age‐0 gizzard shad become unavailable as prey because of rapid growth. Age‐0 gizzard shad growth and environmental data were used to identify at what larval or juvenile stage growth rates diverged among reservoirs and what factors influenced these growth rates. Growth rates diverged during the juvenile stage (>25 mm total length) and varied nearly twofold among three reservoirs. Within a larger data set (30 reservoir‐years including five reservoirs), about 75% of the variation in fall mean length of juveniles was explained by reservoir productivity (indexed by either Secchi depth or chlorophyll‐a concentrations) and juvenile density. Juvenile density was not correlated with reservoir productivity. First‐year growth of gizzard shad was greater in more‐productive reservoirs, apparently because of greater food abundance relative to gizzard shad density.