Vol. 53 - Alaska Resources Library and Information Services

and high resultant mortality. Sonntag et al. (1980) predicted that annual
benthic productivity ("benthic food growth rate") would reach zero
at sediment oil concentrations of 8 to 16 g oil/m², well within the
range of possible sediment concentrations predicted by participants of
the 1981 Anchorage Workshop.
In a realistic spill scenario (about
500,000 barrels of oil; AMOCO CADIZ lost 223,000 mt = 2.47 x 106 barrels
of oil; IXTOC 1 blowout spilled 30,000 barrels day for several months)
several thousand square kilometers could be so impacted and food resources
of crabs reduced on a large scale.
In addition to outright loss of
prey, food consumption could be reduced by a sublethal, anorexic response
to increasing tissue levels of oil as shown for lobster larvae
(Wells and Sprague 1976).
Reduction of food intake by either cause could trigger an energetic
imbalance in which metabolic needs account for the largest expenditure
of ingested energy and little remains for tissue and gamete production
(Edwards 1978).
Sub-optimal temperatures can exacerbate the effect of
oil on growth and energy budgets of a species as theorized by Warren
(1971). Sublethal oil concentrations can act synergistically with suboptimal
temperatures to reduce energy consumption (Edwards 1978) but at
the same time increase respiration even at cold temperatures (Laughlin
and Neff 1977), thereby further narrowing the scope for growth (Warren
1971). Similar impairment of bioenergetic demands may affect pelagic
larvae exposed to sublethal oil concentrations.
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