Fisheries Behavioral Ecology - Abstracts
Stoner, A.W. and E.A. Sturm. 2004. Temperature and hunger mediate sablefish (Anoplopoma fimbria) feeding motivation: implications for stock assessment. Canadian Journal of Fisheries and Aquatic Sciences 61:238-246.
Abstract
Laboratory experiments were conducted to test the hypothesis that temperature (2–8 °C) and recent feeding
history (1–6 days of food deprivation) influence feeding motivation and attacks on baits by adult sablefish (Anoplopoma
fimbria). Activity level after introduction of a bait-related olfactory cue increased with increasing water temperature
and food deprivation. Fish at the lowest temperature (2 °C) attacked and consumed fewer squid baits (33–71%)
than those at higher temperatures (100% at 8 °C). Baits were frequently inspected or handled multiple times before
consumption in low temperatures, and time to attack (seconds to >40 min), time to consume, and time to handle baits
(2–20 s) all decreased significantly with increasing temperature, with some temperature x feeding history interactions.
The total ration consumed increased (<1–8% of body weight) with increasing water temperature. The observed variability
in activity and feeding motivation in sablefish may have a large impact on the effective area of baited gear but is
rarely considered in stock assessment models. In particular, population sizes based upon baited gear surveys may be
underestimated in conditions where temperature is low, natural prey density is high, or where other environmental variables
reduce feeding motivation.
Last updated
27 April, 2007
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