Vol. 53 - Alaska Resources Library and Information Services

viability of the gametes is impaired and normal development of embryos
is arrested, resulting in greatly reduced hatching success. 3) Normal
gametes are produced and eggs fertilized and extruded, but sediment
hydrocarbons are absorbed directly by the lipid-rich developing embryo
and remaining yolk mass. Again, at critically high tissue levels
(unknown), development is arrested and the year-class weakened by virtue
of poor hatch (see Toxicity to Eggs). 4) Oil WSF adversely affects
chemosensory cues used for mating after the females molt, so that
copulation is reduced.
The first hypothesis is
predicated on the possibility that extensive
mortality of epibenthic and infaunal prey would severely restrict
feeding by crabs.
by Curl and Manen 1982)
Scenarios of oil transport to the benthos (summarized
predict accumulation of amounts up to 60 g m[superscript]-
2
and resultant high 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 m[superscript]
-2 , well within
the range of possible sediment concentrations predicted by participants
of the 1981 Anchorage Workshop.
In the very large spill scenario of
about 500,000 bbl of oil, several thousand square kilometers could be so
impacted and food resources of crabs reduced on a large scale.
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).
In
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 might 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 of growth.
406