Fisheries Behavioral Ecology - Abstracts
Manderson, J.P., B.A. Phelan, C. Meise, L.L. Stehlik, A.J. Bejda, J. Pessutti, L. Arlen, A. Draxler, and A.W. Stoner. 2002. Spatial dynamics of habitat suitability for the growth of newly settled winter flounder Pseudopleuronectes americanus in an estuarine nursery. Marine Ecology Progress Series 228:227-239.
Abstract
The relationship between the growth of early juvenile winter flounder (Psuedopleuronectes
[sic] americanus, Walbaum; 17 to 27 mm standard length [SL]) and the spatial dynamics of estuarine
gradients immediately following larval settlement was examined using field enclosure techniques
in a temperate nursery. Enclosures (n = 60; 3 fish per enclosure) were deployed throughout the
Navesink River/Sandy Hook Bay estuarine system, New Jersey, in a nested spatial design that allowed measurement of growth variation in time at 3 spatial scales (between regions: xdistance [D]
= 12.3 km, SD = 3.6, n = 2; between sectors: xD = 4.3 km, SD = 1.3, n = 6; between stations: xD =
1.8 km, SD = 0.8, n = 12). Three 12 d enclosure experiments were performed over 40 consecutive days
from mid-May through June 1999. Flounder growth (range = 0 to 0.9 mm SL d-1 enclosure-1) was
dynamic at a regional spatial scale. Generalized additive modeling indicated that growth was most
rapid at relatively cool temperatures (<21°C) and low salinities (<24‰). However, spatial analysis of
partial growth indicated that the relative influences of temperature and salinity changed over time.
Salinity effects were strongest during the earliest experiment (May 20 to June 1) when temperatures
were cool (<20°C) throughout the estuary. During this period, salinities were conducive for rapid
growth throughout the river. From June 4 to 16, salinities remained optimal in the river, but as the
system warmed, temperatures conducive for rapid growth contracted into the bay and temperature
effects became stronger than salinity effects. Growth was more rapid in the bay, but not as high as
that measured during the first experiment in the river where optimal salinities and temperatures overlapped within the estuary. With continued warming and curtailed freshwater runoff, temperatures
were sub-optimal throughout the estuary, salinities were conducive for rapid growth only in
the upper river, and from June 18 to 30 growth rates were relatively low. Our analysis suggests that
habitat suitability for the growth of juvenile fish can be spatially dynamic because multiple regulatory
factors vary simultaneously in space and time. Rapid growth occurs at sites and times when
optimal conditions for regulatory factors intersect in space, but the spatial coincidence of optimal conditions can be ephemeral.
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27 April, 2007
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