GLOBAL MARINE POLLUTION
A. D. Mclntyre, University of Aberdeen, Aberdeen, UK
& 2009 Elsevier Ltd. All rights reserved.
This aritcle is designed to provide an entry to the
historical and global context of issues related to
pollution of the oceans.
Until recently, the size and mobility of the oceans
encouraged the view that they could not be significantly affected by human activities. Freshwater lakes
and rivers had been degraded for centuries by effluents, particularly sewage, but, although from the
1920s coastal oil pollution from shipping discharges
was widespread, it was felt that in general the open
sea could safely dilute and disperse anything added
to it. Erosion of this view began in the 1950s, when
fallout from the testing of nuclear weapons in the
atmosphere resulted in enhanced levels of artificial
radionuclides throughout the world’s oceans. At
about the same time, the effluent from a factory at
Minamata in Japan caused illness and deaths in the
human population from consumption of mercurycontaminated fish, focusing global attention on the
potential dangers of toxic metals. In the early 1960s,
buildup in the marine environment of residues from
synthetic organic pesticides poisoned top predators
such as fish-eating birds, and in 1967 the first wreck
of a supertanker, the Torrey Canyon, highlighted the
threat of oil from shipping accidents, as distinct from
operational discharges.
It might therefore be said that the decades of the
1950s and 1960s saw the beginnings of marine pollution as a serious concern, and one that demanded
widespread control. It attracted the efforts of national
and international agencies, not least those of the
United Nations. The fear of effects of radioactivity
focused early attention, and initiated the establishment of the International Commission on Radiological Protection (ICRP), which produced a set of
radiation protection standards, applicable not just to
fallout from weapons testing but also to the increasingly more relevant issues of operational discharges
from nuclear reactors and reprocessing plants, from
disposal of low-level radioactive material from a
variety of sources including research and medicine,
and from accidents in industrial installations and
nuclear-powered ships. Following Minamata, other
metals, in particular cadmium and lead, joined mercury on the list of concerns. Since this was seen, like
radioactive wastes, as a public health problem, immediate action was taken. Metals in seafoods were
monitored and import regulations were put in place.
As a result, metal toxicity in seafoods is no longer a
major issue, and since most marine organisms are
resilient to metals, this form of pollution affects ecosystems only when metals are in very high concentrations, such as where mine tailings reach the sea.
Synthetic organics, either as pesticides and antifoulants (notably tributyl tin (TBT)) or as industrial
chemicals, are present in seawater, biota, and sediments, and affect the whole spectrum of marine life,
from primary producers to mammals and birds. The
more persistent and toxic compounds are now banned or restricted, but since many are resistant to
degradation and tend to attach to particles, the seabed sediment acts as a sink, from which they may be
recirculated into the water column. Other synthetic
compounds include plastics, and the increasing use of
these has brought new problems to wildlife and
amenities.
Oil contaminates the marine environment mainly
from shipping and offshore oil production activities.
Major incidents can release large quantities of
oil over short periods, causing immense local damage; but in the longer term, more oil reaches the sea
via operational discharges from ships. These and
other threats to the ocean are controlled by the
International Convention for the Prevention of Pollution from Ships, administered by the International
Maritime Organisation of the UN. Pollution is
generated by human activities, and the most ubiquitous item is sewage, which is derived from a variety
of sources: as a direct discharge; as a component of
urban wastewater; or as sludge to be disposed of after
treatment. Sewage in coastal waters is primarily a
public health problem, exposing recreational users to
pathogens from the local population. The dangers are
widely recognized, and many countries have introduced protective legislation. At the global level, the
London Dumping Convention controls, among other
things, the disposal of sewage sludge. As well as
introducing pathogens, sewage also contributes carbon and nutrients to the sea, adding to the substantial
quantities of these substances reaching the marine
environment from agricultural runoff and industrial
effluents. The resulting eutrophication is causing
major ecosystem impacts around the world, resulting
in excessive, and sometimes harmful, algal blooms.
The need for a global approach to ocean affairs was
formally brought to the attention of the United Nations in 1967, and over the next 15 years, while sectoral treaties and agreements were being introduced,
263
A. D. Mclntyre, University of Aberdeen, Aberdeen, UK
& 2009 Elsevier Ltd. All rights reserved.
This aritcle is designed to provide an entry to the
historical and global context of issues related to
pollution of the oceans.
Until recently, the size and mobility of the oceans
encouraged the view that they could not be significantly affected by human activities. Freshwater lakes
and rivers had been degraded for centuries by effluents, particularly sewage, but, although from the
1920s coastal oil pollution from shipping discharges
was widespread, it was felt that in general the open
sea could safely dilute and disperse anything added
to it. Erosion of this view began in the 1950s, when
fallout from the testing of nuclear weapons in the
atmosphere resulted in enhanced levels of artificial
radionuclides throughout the world’s oceans. At
about the same time, the effluent from a factory at
Minamata in Japan caused illness and deaths in the
human population from consumption of mercurycontaminated fish, focusing global attention on the
potential dangers of toxic metals. In the early 1960s,
buildup in the marine environment of residues from
synthetic organic pesticides poisoned top predators
such as fish-eating birds, and in 1967 the first wreck
of a supertanker, the Torrey Canyon, highlighted the
threat of oil from shipping accidents, as distinct from
operational discharges.
It might therefore be said that the decades of the
1950s and 1960s saw the beginnings of marine pollution as a serious concern, and one that demanded
widespread control. It attracted the efforts of national
and international agencies, not least those of the
United Nations. The fear of effects of radioactivity
focused early attention, and initiated the establishment of the International Commission on Radiological Protection (ICRP), which produced a set of
radiation protection standards, applicable not just to
fallout from weapons testing but also to the increasingly more relevant issues of operational discharges
from nuclear reactors and reprocessing plants, from
disposal of low-level radioactive material from a
variety of sources including research and medicine,
and from accidents in industrial installations and
nuclear-powered ships. Following Minamata, other
metals, in particular cadmium and lead, joined mercury on the list of concerns. Since this was seen, like
radioactive wastes, as a public health problem, immediate action was taken. Metals in seafoods were
monitored and import regulations were put in place.
As a result, metal toxicity in seafoods is no longer a
major issue, and since most marine organisms are
resilient to metals, this form of pollution affects ecosystems only when metals are in very high concentrations, such as where mine tailings reach the sea.
Synthetic organics, either as pesticides and antifoulants (notably tributyl tin (TBT)) or as industrial
chemicals, are present in seawater, biota, and sediments, and affect the whole spectrum of marine life,
from primary producers to mammals and birds. The
more persistent and toxic compounds are now banned or restricted, but since many are resistant to
degradation and tend to attach to particles, the seabed sediment acts as a sink, from which they may be
recirculated into the water column. Other synthetic
compounds include plastics, and the increasing use of
these has brought new problems to wildlife and
amenities.
Oil contaminates the marine environment mainly
from shipping and offshore oil production activities.
Major incidents can release large quantities of
oil over short periods, causing immense local damage; but in the longer term, more oil reaches the sea
via operational discharges from ships. These and
other threats to the ocean are controlled by the
International Convention for the Prevention of Pollution from Ships, administered by the International
Maritime Organisation of the UN. Pollution is
generated by human activities, and the most ubiquitous item is sewage, which is derived from a variety
of sources: as a direct discharge; as a component of
urban wastewater; or as sludge to be disposed of after
treatment. Sewage in coastal waters is primarily a
public health problem, exposing recreational users to
pathogens from the local population. The dangers are
widely recognized, and many countries have introduced protective legislation. At the global level, the
London Dumping Convention controls, among other
things, the disposal of sewage sludge. As well as
introducing pathogens, sewage also contributes carbon and nutrients to the sea, adding to the substantial
quantities of these substances reaching the marine
environment from agricultural runoff and industrial
effluents. The resulting eutrophication is causing
major ecosystem impacts around the world, resulting
in excessive, and sometimes harmful, algal blooms.
The need for a global approach to ocean affairs was
formally brought to the attention of the United Nations in 1967, and over the next 15 years, while sectoral treaties and agreements were being introduced,
263