Detailed information regarding pollution surveys in the Black Sea is to be published in the “First Pollution Assessment of the Black Sea” (BSEP Technical Series publications, November, 1997). The following information summarizes the main results:
Purpose of the surveys
Prior to the start of BSEP, most of the information concerning the concentration of chemical contaminants in the Black Sea is unsupported by information on data quality. This omission is a serious one since analytical techniques for trace contaminants tends to be very prone to errors and without an indication of the size of the errors, the data cannot be regarded as reliable. Very few of the Black Sea laboratories had participated in international intercomparison exercises, except for some sporadic ones for heavy metals which had been organized under the framework of ComEcon in the 1980’s. Furthermore, most of the laboratories lacked the conditions and instruments necessary for producing consistently reliable results.
Establishing a network of proficient, well-equipped laboratories is a task which takes several years to complete and is currently being undertaken in the region. In order to establish a first “baseline” of measurements of the state of pollution in the Black Sea, BSEP and its partners have conducted a series of pilot studies using the Regional Activity Centre for Special Pollution Monitoring in Odessa, specialist laboratories in Sochi (Russia) and Erdemli (Turkey) and with the close cooperation of the Marine Environmental Laboratory of IAEA (Monaco) and a number of centres involved in the EROS-21 experiment, sponsored by the European Union. The pilot surveys covered the following areas: N.W. Black Sea shelf (Danube discharge, Odessa bay, etc.), Russian coast near Sochi, Romanian coastal lagoons (Danube Delta), Area close to the Bosphorus (Turkey). The coverage is far from comprehensive and further work will be needed, especially near coastal hot spots. These results will however, help to establish priorities for future monitoring activities in the region as well as providing a clearer picture of the current state of pollution in the Black Sea.
Of the 111 thousand tons of oil entering the Black Sea each year (see Section A.1.1.), 48% is transported by the Danube river and most of the remainder is introduced from land-based sources through inadequate waste treatment and poor handling of oil and oil products. The amount reaching the Black Sea from ballast water discharges by ships is unknown (the practice is illegal) but though to be considerable.
In the pilot surveys, oil levels were measured in sediments and sea water. The sediment levels were found to be of concern near sea ports (Odessa and Sochi), but in open coast and the Bosphorus outflow areas, the levels were relatively low and correlated with lipid content (the oil was probably transported by organisms). The levels of oil and petroleum hydrocarbons in general in sediments were comparable with those of the Mediterranean. In the EROS measurements of dissolved oil, rather high levels of fresh oil were observed, especially near the discharge of the River Danube. Concentrations found in the surficial waters of the W. Black sea are one order of magnitude higher than in the W. Mediterranean which is consistent with the heavy maritime traffic in the Black Sea. In the suspended particles, the concentration of degraded oil ranged from 10 ng/L in a reference station to 600 ng/L in the Danube river mouth. Concentrations of poly aromatic hydrocarbons (PAH), particularly toxic petroleum hydrocarbon compounds, are generally low and include contributions from petrogenic (oil) and pyrogenic (combustion products) sources.
Pesticides and PCBs
The concentration of these compounds was found to be rather low in most cases. Some slightly elevated concentrations of lindane were found near the Danube discharge (Romanian lagoon samples), but most samples were comparable with the Mediterranean. In order to double-check this situation a “Mussel-Watch” (survey of concentration of chlorinated pesticides and PCBs using mussels as sentinel organisms) will be conducted in autumn 1996. Certainly these compounds are not a major concern to the open Black Sea.
Quite a large amount of reliable data has been gathered on the concentration of heavy metals in the Black Sea. This data has been analyzed in such a manner as to distinguish natural sources of metals from anthropogenic (human-induced) ones. From this analysis, it is quite apparent that the Black Sea is not generally polluted by heavy metals. There are some areas where elevated concentrations may occur (near “industrial hot spots”) and it will be important to complete a more detailed survey of coastal sites. The fact remains however that the heavy metal concentrations in the Black Sea are virtually indistinguishable from natural levels.
There are obvious concerns regarding the level of radionuclides in the Black Sea and, thanks to the sponsorship and guidance of the International Atomic Energy Agency, quite a large effort is underway in this area. Certainly concentrations of some radionuclides are one order of magnitude higher in the Black Sea than the adjacent Mediterranean. Notwithstanding, studies concerning the radiological consequences of radionuclides in the world ocean (MARDOS) and the Mediterranean (MARINA-MED) indicate that doses from anthropogenic radionuclides in the Black Sea are low. Work will continue on this matter under the auspices of the IAEA.
There is little quantitative information on this problem in the Black Sea. Some municipalities in the south and south-east part of the sea are known to be discharging municipal garbage to beaches, the sea or to river banks discharging to the sea. As a consequence, beaches are highly littered. The situation below the waterline is unknown. Steps are already being taken to prevent such sources.
The BSEP pilot survey of microbial contamination was disappointing, largely due to the unwillingness of authorities to use standard methodologies and to exchange data. Even so, the data received showed a “fail rate” for samples of between 5 - 44%. In other words, between 5 and 44% of the samples determined did not meet the sanitary criteria established for the country in question (the data is shown in section A.2.3.). In the Black Sea coastal region, approximately 10,385,000 people have sewerage coverage and discharge an estimated 571,175,000 m3/year into the Black Sea or into downstream stretches of rivers and from there to the sea. The current pilot studies confirmed that regular beach closures occur in many of the Black Sea countries and that, although no cause-effect relationship has been clearly established, there are increasingly frequent outbreaks of serious water borne diseases such as cholera and Hepatitis A. The need for better sewage treatment is evident as is the need for greater transparency in the gathering and diffusion of information on this subject.
Nutrients and eutrophication
This is clearly the main ecological concern in the Black Sea. It is a subject which requires urgent action through the protection of sensitive ecosystems and the reduction of loads. It also requires continued research efforts through programmes designed to develop scientifically based strategies for mitigation. The matter is dealt with extensively in the remaining sections of this TDA.
A detailed monitoring strategy has been prepared and will be published in the “First Pollution Assessment of the Black Sea” (BSEP Technical Series publications, November, 1997). It features an initial screening approach in which the biological effects of pollution are studied using biochemical and biological techniques. The chemical analyses required to detect the nature of the pollutants and for the more routine “status and trends” measurements must be supported by a regionally-based independent system for data quality assurance. A Quality Assurance/Quality Control strategy has been included in the above cited report.
The sections included in this TDA include specific reference to “uncertainties”. These management uncertainties can only be resolved on the basis of a strong research programme and governments are encouraged not to ignore this important matter.
|3.A.2.2||Insufficient information flow and data exchange|
|3.A.2.3||State of recreational waters and beaches in the Black Sea coastal area|
|2.A.2||Monitoring the levels and effects of pollutants for compliance and for long-term trends, data exchange|