‘ _‘ “‘
In comparison With input from human activities, less than 100,000 metric
‘1ÏÏj‘
tons of crude oil are estimated to be released annually in the oceans by natu—
ral leaks from offshore oil deposits such as those near Coal Oil Point, Cali—
fomia [12]. Hydrocarbons produced naturally by marine plants total only
ïïÏ
three million metric tons each year [13]. Furthermore, crude oil and oil prod—
ucts released by man are persistent, toxic chemicals, whereas natural hydro—
carbons released by organic activity are less complex and, with a few exceptions, nontoxic [14]. By 1980, then, the total of 24.7 million tons from the
business of man Will be eight times the entire natural hydrocarbon output
from marine biological activity and from natural underwater seeps—a situa—
tion With seriOus implications for marine life and even for human health.
Despite the predominance of airborne hydrocarbon pollutants, oil pollu—
tion control strategy at sea is aimed primarin at reduction of discharges dur—
ing transport or at cleànup of discharges once they occur. These are necessary
’Ÿ
measures, but a comprehensive strategy requires identication and control of
all sources of pollution throughout the hydrological cycle.
'
The large input of hydrocarbons from human activities also demonstrates
the aw in the popular retort to environmentalists that nature, not man, is the
“
i i i ?—
dominant polluter in the world due to natural processes such as erosion and
volcanic emptions. This sidesteps the problem of toxic pollution, which is
caused not by large-scale geological forces but by the discharge of pollutants
'
such as chemicals and metallic compounds in amounts that are large relative
i
—
to the amounts found naturally in the environment.
Asto the metals, the amounts of at least one—lead—appear to be fairly
evenly divided between man—made and natural sources, With man—made
sources possibly“ having the edge. According to Dr. Edward D. Goldberg of
Scripps Institution of Oceanography:
.
'
In the Northern Hemisphere about 350,000 metric tons of lead, as the anti”{Ï
,
knock agent tetraethyllead, is bumed in automobile internal combustion en—
f
gines and subsequently introduced into the atmosphere. . . . About 250,000
';;j
metric tons of lead is annually washed out over the oceans and about 100,000
metric tons over
in correspondence to their relative areas. Some
'
,
of the land fallôut eventually reaches the oceans as river runoif. This compares
With an annual input of lead into the occans through natural weathering proc—
’,”);
esses of 150,000 metric tons [15].
,
'ÂÏ”;
The concentraüôn of lead, which in excessive amounts can be magnied
:jl‘ÊÏ
along the food chain and become hazardous to aquatic life [16], has risen
from a prehistoric level of about .01 to .02 ppb to a current level of .07 ppbi
*
surface waters d‘fth€ oceans in the Northern Hemisphere. The increase is p‘ri:
marin due to the modern combustion of fuels containing lead [17].
The amount of mercury_that enters the ocean each year from human activities also may beapproaching the amount produced by natural sources,
a“
1Ï _Ë
though there is COn3iderable variation among estimates
because of the
data. At least 25,000 ‘inetric
mercury are washeddeW 1nram into the ocean each year, and
In comparison With input from human activities, less than 100,000 metric
‘1ÏÏj‘
tons of crude oil are estimated to be released annually in the oceans by natu—
ral leaks from offshore oil deposits such as those near Coal Oil Point, Cali—
fomia [12]. Hydrocarbons produced naturally by marine plants total only
ïïÏ
three million metric tons each year [13]. Furthermore, crude oil and oil prod—
ucts released by man are persistent, toxic chemicals, whereas natural hydro—
carbons released by organic activity are less complex and, with a few exceptions, nontoxic [14]. By 1980, then, the total of 24.7 million tons from the
business of man Will be eight times the entire natural hydrocarbon output
from marine biological activity and from natural underwater seeps—a situa—
tion With seriOus implications for marine life and even for human health.
Despite the predominance of airborne hydrocarbon pollutants, oil pollu—
tion control strategy at sea is aimed primarin at reduction of discharges dur—
ing transport or at cleànup of discharges once they occur. These are necessary
’Ÿ
measures, but a comprehensive strategy requires identication and control of
all sources of pollution throughout the hydrological cycle.
'
The large input of hydrocarbons from human activities also demonstrates
the aw in the popular retort to environmentalists that nature, not man, is the
“
i i i ?—
dominant polluter in the world due to natural processes such as erosion and
volcanic emptions. This sidesteps the problem of toxic pollution, which is
caused not by large-scale geological forces but by the discharge of pollutants
'
such as chemicals and metallic compounds in amounts that are large relative
i
—
to the amounts found naturally in the environment.
Asto the metals, the amounts of at least one—lead—appear to be fairly
evenly divided between man—made and natural sources, With man—made
sources possibly“ having the edge. According to Dr. Edward D. Goldberg of
Scripps Institution of Oceanography:
.
'
In the Northern Hemisphere about 350,000 metric tons of lead, as the anti”{Ï
,
knock agent tetraethyllead, is bumed in automobile internal combustion en—
f
gines and subsequently introduced into the atmosphere. . . . About 250,000
';;j
metric tons of lead is annually washed out over the oceans and about 100,000
metric tons over
in correspondence to their relative areas. Some
'
,
of the land fallôut eventually reaches the oceans as river runoif. This compares
With an annual input of lead into the occans through natural weathering proc—
’,”);
esses of 150,000 metric tons [15].
,
'ÂÏ”;
The concentraüôn of lead, which in excessive amounts can be magnied
:jl‘ÊÏ
along the food chain and become hazardous to aquatic life [16], has risen
from a prehistoric level of about .01 to .02 ppb to a current level of .07 ppbi
*
surface waters d‘fth€ oceans in the Northern Hemisphere. The increase is p‘ri:
marin due to the modern combustion of fuels containing lead [17].
The amount of mercury_that enters the ocean each year from human activities also may beapproaching the amount produced by natural sources,
a“
1Ï _Ë
though there is COn3iderable variation among estimates
because of the
data. At least 25,000 ‘inetric
mercury are washeddeW 1nram into the ocean each year, and