ES&T
OUTLOOK The marine environment How healthy are the oceans? The world's oceans are much healthier than they were thought to be at the Stockholm Conference 10 years ago. The marine environment is taken to include estuaries, coastal waters, and the open ocean. It is an area from which humans extract living and nonliving resources. It is used for recreation and waste disposal, and it plays a fundamental role in maintaining present conditions for life on the earth. Although the open seas are in fine shape, coastal waters are not. For instance, there are "hot spots" that need action. These hot spots range in size from a few square meters around a discharge pipe to the full extent of a major estuary, and they can encompass specific habitats or ecosystems such as salt marshes, kelp beds, mangrove swamps, and coral reefs. Most of these future threats to the marine environment will have their main potential impact on the coastal zone. Such are the findings of a report, "Health of the Oceans," prepared by the United Nations Environment Programme (UNEP). Written by the world's leading marine scientists, the report was four years in the making and will be updated in another four years. These scientists make up the group, GESAMP, the Joint Group of Experts on the Scientific Aspects of Marine Pollution. Interactions with air and land The report points out that the world's oceans cannot be regarded as isolated entities since they interact intimately with the atmosphere, the seafloor, and the continents—from all of which they receive input. Continent (land) and atmosphere have been given a major place in the report—in view of processes that affect the fluxes both within the marine environment and between the oceans. The first GESAMP report, "UNEP Regional Seas Report and Studies No. 0013-936X/82/0916-0643A$01.25/0
Océanographie research. This core sample is used for checking heavy metals in coastal waters.
© 1982 American Chemical Society
Environ. Sci. Technol . Vol. 16. No. 12, 1982
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Now You Can Rapidly Assess The Toxicity off Waste Material, Leachate or Effluent Samples.
16," treats five categories of substances—sewage, chloroorganics, petroleum, metals, and radionuclides. Other substances will be treated in subsequent reports. The report is addressed to scientific administrators and decision makers concerned with the state of the marine environment and its protection. It is composed of technical papers (chapters) that were written by individual scientists and which were used by the Task Groups of G E S A M P . These seven chapters are factual and technical, and include references to the open literature.
In minutes, the Microtox™ Toxicity Analyzer can: • Quantitate the relative toxicity of hazardous waste samples • Monitor clean-up efficiency at waste or chemical spill sites • Determine toxicity of leachates from and test well samples surrounding dump sites • Establish toxicity of industrial and municipal WWTP effluents • Protect WWTP from toxic shock • Save time and money by quickly identifying samples which require further analysis The Microtox™ Toxicity Analyzer provides toxicity information in less than 30 minutes utilizing a simple but highly effective biological test technique. This test is particularly useful for establishing the toxicity of complex samples whose individual components are present in non-toxic levels, but in combination are acutely toxic Beckman's rapid test uses a specially selected strain of luminescent bacteria. Upon exposure to toxic material the light output of these bacteria diminish in direct proportion to the concentration of toxicants present. Sensitivity is similar to conventional bioassays, but test results are obtained in minutes, not days. The test procedure is simple, cost effective and reproducible. Microtox™ users include state environmental and U.S. EPA Labs where applications include hazardous waste monitoring and effluent monitoring. For more information, including application data specific to hazardous waste materials or effluent monitoring, write: Beckman Instruments, Inc, 6200 El Camino Real, Carlsbad, CA 92008.
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Environ. Sci. Technol., Vol. 16, No. 12. 1982
Atmospheric measurements. Instruments on board ship measure wind, temperature, humidity, and radiation; line in foreground is attached to a sea-temperature sensor. The five topics Harmful effects of pollution can be seen. Semienclosed seas such as the Gulf of Mexico, the Mediterranean Sea, the North Sea, and the Baltic Sea receive substantial contamination, some of which is sewage. The use of the coastal zone for sewage disposal is worldwide, and the input is increasing. But, according to the report, "if the disposal of sewage to the sea is adequately controlled and if the sites are properly selected so that the assimilative capacity is not exceeded, then the fertilizing nature of the sewage may be regarded as more significant than its potential toxicity." With regard to petroleum, the report continues, "Oil spill effects on deep sea communities are rarely drastic; recovery is usually a question of weeks or months. But the impact on intertidal and subtidal communities may be severe, with recovery taking
years or decades. Birds are particularly at risk, but there is no evidence that oil alone can threaten species' survival." As for PCBs, according to the report, there is no confirmed record of human illness having been caused by consumption of marine organisms that contained PCBs. However, the concentration of PCB residues in some marine organisms exceeds the level set by some national authorities to safeguard human health. On the other hand, heavy metal concentrations generally recorded in shellfish and fish do not suggest any threat to the average human consumer, and they rarely damage the ecosystem, the report says. Addressing radionuclides, the report notes that "over the past two decades, methods have been employed to regulate the introduction of radioactive materials to the sea. These are based on the concept that there exists an environmental capacity that can be calculated, using critical pathway techniques. The utility of the application of this approach to the controlled release of other materials is worthy of careful consideration." Prognosis New techniques for waste disposal should be evaluated. The incineration of chemical wastes at sea and the burial of contaminated solid waste in the seabed under a cap of clean sediment should be kept under review, according to suggestions in the report. It would be difficult, if not impossible, to monitor the seas for all potential contaminants. But there is a strong case for monitoring selected substances in the oceans. The focus is on toxic substances that are produced and used commercially. The field effort is concentrated on geographical areas of known input. The scientists want to obtain the necessary data to make better predictions of environmental impact. The important issue is perhaps not so much to name new potential pollutants, the report says, but rather to develop a strategy for approaching the problem. Continued development and standardization of analytical techniques are important aspects of the problem. Although effects of pollution have not yet been detected on a global scale, general trends of contamination can be recognized in some areas, and these trends are warning signals. The signals are noticeable mainly in the marine areas most intensively used by humans—coastal waters. —Stanton Miller
