Establishment of a geographical area of analysis and study, outside the Black Sea Basin that could present a risk of pollution.

Introduction

As the pollution of the Black Sea does not only come from the pollution of coastal areas and from the pollution of maritime transport and offshore gas exploitation, we decided to establish an extended area of the Black Sea Basin, for analysis and study that presents a very high risk of pollution for Black Sea waters. in order to have a real and complete overview of all the sources of pollution of the Black Sea. We have established this geographical area as being outside the Black Sea Basin, calling it the Extended Black Sea Basin and it will more accurately reflect the situation of all potential existing sources of pollution.

The extended hydrographic basin of the Black Sea includes the sum of the hydrographic basins of the 6 countries Romania, Ukraine, Russia. Georgia, Turkey and Bulgaria and the Danube river basin that collects waters from 18 other riparian countries in central and southeastern Europe (Albania, Austria, Bosnia and Herzegovina, Bulgaria, Croatia, Switzerland, the Czech Republic, Germany, Italy, Macedonia, Moldova, Poland, Romania, Serbia and Montenegro, Slovakia, Slovenia, Ukraine and Hungary).

Extensive Black Sea Basin

In Figure no. 1 shows the Black Sea Basin (respectively geographical area of analysis)

Fig.1 The extended river basin of the Black Sea

The ecological status of the Black Sea depends largely on the anthropogenic pressure of a territory of 20 countries, with an area of 800,000 km2, inhabited by a population of about 100 million inhabitants, with many industrial activities generating pollutants with a special impact on the Basin. Extensive hydrographic and marine environment of the Black Sea.

In the years 1960-1990 due to excessive pollution throughout the basin it is considered that the Black Sea is in great danger of becoming a dead sea from an ecological point of view. For example, only the Danube, which was considered the collecting channel of Central Europe, contributed 30% to the total pollution of the Black Sea.

The main pollutants that reach the Black Sea waters are:

• toxic substances (permanent organic pollutants, pesticides)
• radioactive substances (radionuclides)
• heavy metals (Cd, Cu, Zn, Fe, Ca, Hg)
• petroleum products (hydrocarbons, petroleum residues)
• inorganic nutrients (nitrates, nitrites, phosphates)
• household waste (plastic, garbage).

The most important factor with a high risk of pollution of the Black Sea is the contribution of polluted waters from the entire extended river basin. The extensive river basin of the Black Sea consists of the sum of the basins of large rivers whose water supply is in percentages as follows:

1. Danube 200 km3 (57.5%)
2. Dnieper 43.5 km3 (12.5%)
3. Rioni 13.37 km3 (3.8%),
4. Dniester 9.1 km3 (2.6%)
5. Chorokhi 8.71 km3 (2.5%)
6. Kizil-Irmak 5.90 km3 (1.7%)
7. Sakarya 5.60 km3 (1.6%)
8. Yesil-Irmak 5.30 km3 (1.5%)

There are about a thousand rivers that flow into the Black Sea and all are significantly different in both water volume and basin size, These have not been fully studied. However, the existing data sets on the total discharge of fresh water into the Black Sea estimate between 294 k3 per year and 474 km3 per year. Thus, the flow of the river into the Black Sea is dependent on the geographical area and on average the rivers supply 348 km3 of fresh water per year in the sea.

The contribution of the 10 large rivers and streams that flow into the Black Sea is 86% of the total.

• Under natural conditions, the spill would have been more than 381 km3.
• In addition to the surface discharge, at least 17 cubic kilometers of fresh water reach Black Sea from underground sources.
• Precipitation contributes another 238 km3 (average annual rainfall 562 mm).

Thus, the annual volume of fresh water entering the Black Sea (river water plus rainfall plus underground sources) is on average 603,000,000,000 m3.

The impact of pollution in the Extended Basin on the ecological status of the Black Sea.

In the waters of the Extended River Basin collected in the waters of the Black Sea are found the following persistent organic pollutants POP * in water and sediments: lindane, heptachlor, aldrin, dieldrin, phenols and heavy metals: Cd, Cu, Zn, Fe, Ca, Hg.

Their level generally varies in water from the limit of detection to concentrations up to 0.12 μg / L, and in sediment from the limit of detection to 0.027 μg / g sediment. In the case of these contaminants, the concentrations frequently exceed the threshold values that define good ecological status. Other investigated compounds (endrin, phenols, heavy metals) have much lower concentrations, which vary in water between the detection limit and concentrations up to 0.03 μg / L, and in sediments between the detection limit and 0.007 μg / g sediment . Of particular interest is the presence of contaminants in fish and other marine organisms intended for human consumption. By contaminants we mean, according to European legislation, “dangerous substances present in marine organisms, as a result of environmental contamination, for which limits have been set for human consumption or whose presence in fish is relevant”.

Persistent organic pollutants and heavy metals have been associated with a significant impact on the environment in terms of a wide variety of species and virtually all trophic levels.

Many persistent organic pollutants and heavy metals have been implicated in a wide variety of adverse effects on the environment and human health, including impaired reproduction, endocrine disorders, reduced immunity, and cancer. In addition, exposure to these contaminants has been correlated with population decline in several marine mammals. Adverse effects associated with chronic exposure to low levels of environmental contamination are of particular interest because they may affect the stability of the entire ecosystem.

Another type of pollution is pollution with inorganic nutrients: nitrates, nitrites, phosphates, which in seawater cause the phenomenon of seaweed flourishing, with a special impact on the balance of marine ecosystems by depriving biological oxygen and also with aesthetic impact on tourism on coast.

Fig.2 The situation of nitrate pollution in the extended Black Sea basin

Along the rivers in the Extended Hydrological Basin, nitrate pollution occurs with a direct impact on the health of the population, especially for the health of young children.

Figure 2 shows the situation of nitrate pollution in the Extended Hydrological Basin of the Black Sea. It is observed from the analysis of the six most important river basins that the most polluted in nitrate discharges are the Dniester basin and the Kizilmark basin. The Don basin has a medium pollution, the Sakaria and Dnieper basins have a low pollution.

In the Danube basin, some measures have been taken to reduce nitrate pollution. In this basin there are some sources still unresolved (industrial areas such as Gabrovo, Linz).

In order to monitor this huge volume of water supply, which is particularly important for the ecological state, special measures are needed applied for the entire extended Black Sea basin.

A good example of monitoring and measures for water quality monitoring is provided by the TNNN Transnational Monitoring Network – Transnational Monitoring Network of ICPDR – International Commission for the Protection of the Danube, which regularly monitors water quality in the Danube river basin, In figure no. 3 illustrates the Situation of Water Quality Monitoring in the Danube River Basin

Fig.3 Water quality monitoring stations in the Danube River Basin

This monitoring measure does not have a spectacular effect on Danube pollution. Several forces should be mobilized and corroborated in order to take concrete and efficient measures for greening the Danube waters.

Geographically, the Black Sea region connects the northeastern part of Europe with its eastern-southern part; therefore, it is a strategic intersection not only for many EU and NATO countries, but also for Russia, as clearly demonstrated by the events in Georgia in 2008 and Crimea in 2014. Consequently, as the region becomes a prominent theater of mutual interest, the greater the chances of an open confrontation in its area or even the emergence of a type of hybrid conflict.

Concluzii.

1.  Pollution in the Extended River Basin has a special impact on the ecological status of the Black Sea, with several significant locations, the Dniester, the Dnieper, the Kerch Strait at the Sea of Azov, the Kizilmark River, the Bosphorus, but especially the Danube. 30% of total pollution.
2. The ecological situation of the Black Sea, despite the measures to reduce pollution, is still fragile, so it is observed the reduction of the oxygen-rich seawater layer, the increase of the anoxic seawater layer (rich in H2S – hydrogen sulfide), the imbalance marine ecosystems, species extinctions and diminishing fish stocks.
3. Also the salinity of the Black Sea water is particularly low: between 7 and 10 g / l due to the massive fresh water inputs (603X109 m3 / year), unlike the Mediterranean Sea which has an average salinity of 35 g / l

* Definition of POP – persistent organic pollutants
Persistent organic pollutants (acronym POP) are organic compounds resistant to the chemical, biological and photolytic action of environmental agents, so they are resistant to degradation.
12 such persistent organic pollutants are known to have toxic properties, negatively influencing the life of living organisms.

• pesticides: aldrin, dildrine, dichloro-diphenyl-tetrachloroethane (DDT), heptachlor, mirex,
  chlordane, taxofen, endrin;
• industrial chemicals: hexachlorobenzol pesticide (HCB), polychlorinated biphenyls
  (polychlorinated biphenyl, PCB);
• combustion by-products: dioxins (especially polychlorodibenzo-para-dioxins),
  furans (especially polychlorodibenzofurans).

Many POPs are or have been used as pesticides, solvents, pharmaceuticals and industrial chemicals. Although some POPs are also produced naturally, as in volcanoes and some metabolic pathways, most are man-made by total chemical synthesis.

Sources

1. Black Sea State of Environment report 2009-2014 www.blacksea-commission.org
2. Commission for the Protection of the Black Sea against Pollution http://www.blacksea-commission.org/
3.  Event reports https://blackseablueconomy.eu/publication-categories/deliverables
4.  BSIMAP Integrated Black Sea Monitoring and Evaluation Program www.europa.eu

Author: Raul Hangu – ECOM Team Romania