Vol. 53 - Alaska Resources Library and Information Services

One or two very weak year-classes resulting from oil pollution may
have important, though unknown, ecological ramifications via impacts
on epibenthic and infaunal communities.
Jewett and Feder
(1981) reported that commercial crabs comprise 55% and 82% of epifaunal
biomass on the middle (40-100 m) and outer (>100 m) shelves,
respectively.
Reduction of this enormous predator/prey group by
catastrophic loss of larvae could radically alter the community
composition, perhaps by an increase of echinoderms (sea stars) that
are also abundant.
The effect of this may be to slow recovery of
crab stocks faced with large populations of competitors that increase
to replace one or two years of crabs lost to oil.
Populations
of the crab Uca pugnax were still adversely affected 7 years
after a small oil spill at West Falmouth, Massachusetts, that reduced
the overall population, lowered female to male ratios, reduced
juvenile settlement, and caused heavy winter mortalities and
behavioral anomalies (Krebs and Burns 1978).
8.4 Extent of Area Affected by Oil
Scenarios considered by participants of the 1981 Anchorage OCSEAP
Workshop included only spills or blowouts that released 50,000 barrels
which, in retrospect, is a quantity far less than might be expected from
mishaps involving modern tankers.
Oil spill scenarios used during the
North Aleutian Shelf Synthesis meeting in Anchorage (March 1982) were
even smaller for the southeastern Bering Sea.
Exceedingly small spills
of 10,000 barrels were modelled by Pelto (1983) and covered relatively
small areas of the Bering Sea (20 km by less than 1 km).
The AMOCO
CADIZ released 223,000 mt = 2.47 x 106 barrels of oil (1 barrel = 35
816