Fisheries Behavioral Ecology - Abstracts
Hurst, T.P. and A.A. Abookire. 2006. Temporal and spatial variation in potential and realized
growth rates of age-0 year northern rock sole. Journal of Fish Biology 68:905-919.
Abstract
The possibility of prey limitations on the growth performance of age-0 year northern rock sole Lepidopsetta polyxystra was evaluated at three sites along the north-east coast of Kodiak Island,
Alaska, U.S.A., by comparison of observed to potential growth rates. Growth potential
was measured in the laboratory across the range of temperatures encountered by this species
during the first summer of life. Growth potential (gL, mm day-1) increased with water temperature
(T) between 2 and 13°C, according to: gL = 0.0151 + 0.3673·log10(T). There were significant
differences in growth rate between the three field sites such that Holiday Beach fish were
7.1 mm longer than Shakmanof Beach fish by mid-September, with Pillar Creek Cove fish of
intermediate size. Temperature differences between sites accounted for less than half of this
variation. The remainder may have been related to differences in prey availability among the
sites in association with observed differences in sediment characteristics. In addition to the spatial
variability, there was significant monthly variation in growth performance. Realized growth rates
between July and August were in excess of 85% of potential. Between August and September,
however, realized growth fell to 43–71% of potential indicating a decline in conditions for
growth. The spatial variation in growth rates was not density-dependent as the site with the
highest fish densities (Holiday Beach) also supported the highest growth rates. The available data
indicates that for this subtidal species, interannual variation in growth may be more important
than site variation.
Last updated
26 April, 2007
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