TY - JOUR
T1 - Causes of Interestuarine Variability in Bay Anchovy (emAnchoa Mitchilli/em) Salinity at Capture
AU - Peebles, Ernst B.
AU - Burghart, Scott E.
AU - Hollander, David J.
PY - 2007/1/1
Y1 - 2007/1/1
N2 - Salinities occupied by different life stages of bay anchovy ( Anchoa mitchilli ) were compared over annual cycles at 128 stations in 12 Florida estuaries. The comparison included eight stations in an oligotrophic, groundwater-based estuary in which all life stages were rare or absent. At other stations, adults, eggs, and early larvae occurred in intermediate to high salinities (10-30 psu) with no apparent central salinity tendency. The larva-juvenile transition was marked by an upstream shift to lower salinities (0-15 psu), also with no central salinity tendency. Mean salinities of the juvenile catch were strongly dependent on the salinities of the sampling effort. This dependence was strongest in estuaries that had weak horizontal salinity gradients. Weak salinity gradients were either natural or resulted from estuarine dams. After using nonlinear regression to account for the interaction between effort salinity and catch salinity, catch salinities were found to be similar from year to year within estuaries, but widely different among estuaries, with interestuarine differences ranging as high as 10–13 psu. Lower salinities were occupied by juveniles in estuaries that had long freshwater turnover times. Inherent geomorphic and inflow-related effects on the distribution of prey resources, coupled with an ontogenetic diet shift, are proposed as the explanation for both the habitat shift and the strong interestuarine variability in salinity at capture.
AB - Salinities occupied by different life stages of bay anchovy ( Anchoa mitchilli ) were compared over annual cycles at 128 stations in 12 Florida estuaries. The comparison included eight stations in an oligotrophic, groundwater-based estuary in which all life stages were rare or absent. At other stations, adults, eggs, and early larvae occurred in intermediate to high salinities (10-30 psu) with no apparent central salinity tendency. The larva-juvenile transition was marked by an upstream shift to lower salinities (0-15 psu), also with no central salinity tendency. Mean salinities of the juvenile catch were strongly dependent on the salinities of the sampling effort. This dependence was strongest in estuaries that had weak horizontal salinity gradients. Weak salinity gradients were either natural or resulted from estuarine dams. After using nonlinear regression to account for the interaction between effort salinity and catch salinity, catch salinities were found to be similar from year to year within estuaries, but widely different among estuaries, with interestuarine differences ranging as high as 10–13 psu. Lower salinities were occupied by juveniles in estuaries that had long freshwater turnover times. Inherent geomorphic and inflow-related effects on the distribution of prey resources, coupled with an ontogenetic diet shift, are proposed as the explanation for both the habitat shift and the strong interestuarine variability in salinity at capture.
KW - Marine Ecology Progress Series
KW - Freshwater Inflow
KW - Calanoid Copepod
KW - American Fishery Society
KW - Ontogenetic Habitat Shift
UR - https://digitalcommons.usf.edu/msc_facpub/2263
UR - https://doi.org/10.1007/BF02841396
U2 - 10.1007/BF02841396
DO - 10.1007/BF02841396
M3 - Article
VL - 30
JO - Estuaries and Coasts
JF - Estuaries and Coasts
ER -