Fisheries Behavioral Ecology - Abstracts
Stoner, A.W. and A.A. Abookire. 2002. Sediment preferences and size-specific distribution of young-of-the-year Pacific halibut in an Alaska nursery. Journal of Fish Biology 61:540-559.
Abstract
A combination of laboratory experiments and field surveys was used to test the hypotheses that
responses to sediments change with fish size and that sediment grain-size is the predominant
environmental factor affecting small-scale distribution in young-of-the-year (yoy) Pacific
halibut Hippoglossus stenolepis. Laboratory tests showed that the smallest fish (31–40 mm LT)
chose fine sediments (muddy and fine sands), fish 51–70 mm had high selectivity (primarily
medium sand), and the largest fish (80–150 mm) were not selective although they avoided the
largest grain-sizes (pebbles and granules). Sediment preferences were correlated with size-dependent
burial capabilities. Beam trawl collections were made over a 6 year period in
Kachemak Bay, Alaska, to examine the distribution of yoy Pacific halibut (14–120 mm LT)
using small size classes (e.g. 10 mm intervals). Canonical correlation analysis showed that the
per cent of sand in the sediment was a highly significant variable for all but one size and date
combination. Catch per unit of effort (CPUE) for newly settled fish (<30 mm LT) was highest
on very fine sand, fish 41–80 mm were most abundant on fine sand, and the largest yoy fish
(81–120 mm) were abundant over a range of sediments from fine sand to mud. Except for the
smallest fish, Pacific halibut in the field were associated with sediments somewhat finer than
predicted from the laboratory experiments; however, virtually all were captured where they
could bury easily. The ability of flatfish to bury and shelter in sediment is related to fish size;
consequently, habitat associations shift rapidly during the first year of life. Habitat models for
yoy flatfishes should consider size-dependent shifts in capabilities and preferences.
Last updated
27 April, 2007
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