United States
Environmental Protection
Agency
Environmental Research
Laboratory
Corvallis OR 97333
or:^
Research and Development
EPA/600/S3-86/018 Apr. 1986
&EPA Project Summary
Sources, Fates and Effects of
Aromatic Hydrocarbons in the
Alaskan Marine
Environment with
Recommendations for
Monitoring Strategies
J. W. Anderson, J. M. Neff, and P. D. Boehm
Information about polycyclic
aromatic hydrocarbons in the Alaskan
marine environment is relatively sparse.
About 300 references were reviewed to
create an assessment of the current
state of knowledge on sources, fates
and effects of oil-derived polycyclic
aromatic hydrocarbons in cold marine
waters.
This Project Summary was developed
by EPA's Environmental Research
Laboratory, Corvallis, OR, to announce
key findings of a literature review that is
fully documented in a separate report of
the same title (see Project Report
ordering information at back).
Introduction
The objective of the full report is to
critically review what is known about the
sources, fates and effects of polycyclic
aromatic hydrocarbons (PAH) in the
Alaskan marine environment. Based on
this review, several information needs
are identified and recommendations
made for the design of research and
monitoring strategies to fill these needs.
The specific areas reviewed are 1) the
natural and anthropogenic sources of
aromatic hydrocarbons in the Alaskan
marine environment, 2) the physical,
chemical and biochemical fates of these
compounds in marine ecosystems.
and 3) the bioaccumulation and bio-
logical effects of aromatic hydrocarbons
in marine organisms.
Findings
The major point sources of polycyclic
aromatic hydrocarbons (PAH) in the
Alaskan marine environment are
discharges of treated produced water,
crude oil tanker ballast water and
domestic/industrial sewage. These, as
well as new point sources of PAH, can be
expected to increase in number and
volume as offshore reserves of oil and gas
are developed and industrial activity in
Alaska increases. Currently, these point
sources contribute only a small portion of
the total PAH entering the Alaskan
coastal waters from all sources. Major
non-point sources of PAH in Alaskan
coastal waters and sediments are aerial
deposition of particle-bound PAH derived
from remote industrial and other
combustion sources. Burning of wood for
home heating and in controlled or wild
forest fires may be major sources of
airborne particulate PAH in some parts of
Alaska. Additional important sources of
PAH include erosion of peat and coal
deposits and submarine oil seeps.
The composition of hydrocarbon
assemblages in marine sediments of
developed and remote areas of Alaska
reveal a predominantly biogenic (natural)
and pyrogenic (combustion) origin. Oil
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spilled in the ocean under arctic and
subarctic conditions similar to those in
Alaska tends to be quite persistent. In
coastal areas characterized by high
suspended sediment loads, such as Cook
Inlet, the Beaufort Sea and Norton Sound
off the Yukon River, PAH from spilled oil
will adsorb rapidly to suspended
sediment and be transported to the
bottom, where they are quite persistent.
Evaporation of low molecular weight
aromatic hydrocarbons is slow at low
water temperatures and is nearly
completely impeded by ice cover.
The main mechanisms of removal of
PAH and related hydrocarbons from
Alaskan marine waters are evaporation,
photochemical and chemical degrada-
tion, and metabolism by marine bacteria,
fungi, phytoplankton, and animals. In
Alaskan waters, these processes tend to
proceed more slowly than at lower
latitudes because of low ambient
temperatures and low net incident solar
radiation during much of the year. Thus,
PAH introduced into Alaskan waters by
natural mechanisms, intentional dis-
charges, or accidental spills will tend to
persist and may accumulate over time to
high concentrations in Alaskan marine
sediments.
Alaskan marine animals readily
accumulate PAH and related
hydrocarbons during exposure to these
compounds in the water, food, or
sediment. Bioaccumulation is most rapid
and efficient from the water. However,
since PAH reach high concentrations and
are more persistent in sediments than in
water, the major source of PAH for
benthic and demersal marine animals is
from contaminated sediments.
Bioconcentration factors (concentration
in tissues/concentration in medium) for
PAH increase with increasing PAH
molecular weight and tend to be higher in
marine molluscs than in polychaetes,
crustaceans, and fish. This is directly
related to the relative capability of these
taxa to metabolize and excrete PAH.
Because PAH are metabolized by
members of higher trophic levels, there is
no evidence of biomagnification of PAH in
marine food webs.
Low temperatures, characteristic of
Alaskan waters, have only a slight effect
on rate of accumulation of PAH in marine
animals but do seem to slow metabolic
degradation and excretion of ac-
cumulated PAH. The slower rate of
depuration plus the greater persistence of
PAH in low temperature marine
environments may mean that the potential
for chronic impacts of PAH pollution of the
Alaskan marine environment is greater
than for more temperate and tropical
climates.
Alaskan marine animals do not appear
to be significantly more sensitive to
aromatic hydrocarbons than similar
species from more temperate and tropical
climates. However, because of the greater
persistence of light aromatics and PAH in
cold Alaskan waters, biological impacts of
an Alaskan oil spill may be more severe
and subsequent recovery slower than for a
similar spill in a warmer climate. However,
many marine communities in Alaskan
coastal environments are already
naturally stressed by the severe climatic
conditions. Such communities recover
rapidly following a disturbance such as an
oil spill or cessation of a chronic pollutant
discharge. The Alaskan marine
populations most likely to be severely
damaged by oil spills and chronic dis-
charges are the large, long-lived species
such as king crabs, salmon, and marine
mammals.
Conclusions
Based on this literature review.it is
concluded that the following additional
information is needed to more accurately
assess the impact of aromatic
hydrocarbons: a quantitative inventory
of PAH sources in the Alaskan marine
environment; composition over time of
produced water and ballast water
discharges and their long-term fate after
discharge to Alaskan coastal waters;
sensitivity to and PAH metabolism by
populations and communities of marine
animals from the high arctic (Chukchi and
Beaufort Seas); and field validation of
arctic oil spill models. To address these
needs, the design of long-term
monitoring studies is presented to assess
the environmental impacts of produced
water discharges to Cook Inlet and of
offshore oil and gas development in the
Beaufort Sea.
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J. W. Anderson is with Pacific Northwest Laboratory, Sequim, WA 98382, J. M.
Nell, and P. D. Boehm are with Battelle, Duxbury, MA 02332.
James C. McCarty is the EPA Project Officer (see below).
The complete report, entitled "Sources, Fates and Effects of Aromatic Hydro-
carbons in the Alaskan Marine Environment with Recommendations for
Monitoring Strategies," (Order No. PB86-168 291 /A S; Cost: $22.95, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Engvironmental Research Laboratory
U.S. Environmental Protection Agency
Corvallis, OR 97333
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use S300
EPA/600/S3-86/018
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