the Black sea after the Chernobyl accident was the reason for multiple studies on
radionuclide accumulation processes in biota. The Black sea received a great
amount of radionuclide impact due to its geographical position as the closest marine
basin to the accident site. The technogenic radionuclides got into the marine
ecosystems through atmospheric fallout and through the big rivers Danube, Dnieper
and Dnester that enter the northwest Black sea corner. For this reason, the level of
anthropogenic nuclides should be monitored to evaluate the radioactivity transfer
along the trophic chain and assess the radiation risk for biota in the marine
ecosystem.
Since 1945 there has been a continuous release of technogenic radionuclides to
the environment started, leading to their accumulation in the seas and oceans, the
main source of contamination being nuclear weapons tests in the atmosphere, on
land and in water. The Bulgarian Black Sea coast received a great amount of
radionuclide impact during nuclear tests in 1960s and after 1986 being close to
Chernobyl NPP, a considerable direct atmospheric radionuclide fallout occurred in
the environment, Additionally, Chernobyl nuclides entered the marine environment
mostly in the northwest corner of the Black Sea carried by the big rivers – Dnyepr,
Dnester, Danube (Keondjan et al. 1990) plus pollutant emissions carried by the
local rivers (Tuncer et al. 1998).
Marine sediments are widely used for environmental control because of their
ability to accumulate various pollutants. Macroalgae are another important medium
for nuclide accumulation in marine ecosystems. Radionuclides affect the living
organisms both as heavy metals and by their radiation. They participate in radionuclide and heavy metal transfer to the biosphere and man as elements of the food
chain of marine biota. Many authors have investigated migration of radionuclides
as well as biological effects of ionizing radiation in the Black sea environment.
18.2 Radioecological Studies of Black Sea Ecosystems
18.2.1 Romanian Marine Research
A semi-enclosed tideless basin bordering six countries, the Black Sea is still
considered a “unicum hidrobiologicum” because of its physical, chemical, and
biological peculiarities; unlike any other sea. The Black Sea is permanently deficient in oxygen, or anoxic below a depth of 150–200 m (Bologa 1994). Major
factors contributing to the deterioration of the Black Sea environment are pollution
and improper use of natural resources (Osvath et al. 1998). The Black Sea is a
unique marine environment, one especially exposed to anthropogenic impact.
Almost landlocked, besides the link with the shallow inland Azov Sea, its only
exchange of water with the World Ocean is through the narrow Bosporus Strait.
As to radioactive contamination, different IAEA programmes showed that
concentration of anthropogenic radionuclides in the Black sea environment,
300
A. Strezov
radionuclide accumulation processes in biota. The Black sea received a great
amount of radionuclide impact due to its geographical position as the closest marine
basin to the accident site. The technogenic radionuclides got into the marine
ecosystems through atmospheric fallout and through the big rivers Danube, Dnieper
and Dnester that enter the northwest Black sea corner. For this reason, the level of
anthropogenic nuclides should be monitored to evaluate the radioactivity transfer
along the trophic chain and assess the radiation risk for biota in the marine
ecosystem.
Since 1945 there has been a continuous release of technogenic radionuclides to
the environment started, leading to their accumulation in the seas and oceans, the
main source of contamination being nuclear weapons tests in the atmosphere, on
land and in water. The Bulgarian Black Sea coast received a great amount of
radionuclide impact during nuclear tests in 1960s and after 1986 being close to
Chernobyl NPP, a considerable direct atmospheric radionuclide fallout occurred in
the environment, Additionally, Chernobyl nuclides entered the marine environment
mostly in the northwest corner of the Black Sea carried by the big rivers – Dnyepr,
Dnester, Danube (Keondjan et al. 1990) plus pollutant emissions carried by the
local rivers (Tuncer et al. 1998).
Marine sediments are widely used for environmental control because of their
ability to accumulate various pollutants. Macroalgae are another important medium
for nuclide accumulation in marine ecosystems. Radionuclides affect the living
organisms both as heavy metals and by their radiation. They participate in radionuclide and heavy metal transfer to the biosphere and man as elements of the food
chain of marine biota. Many authors have investigated migration of radionuclides
as well as biological effects of ionizing radiation in the Black sea environment.
18.2 Radioecological Studies of Black Sea Ecosystems
18.2.1 Romanian Marine Research
A semi-enclosed tideless basin bordering six countries, the Black Sea is still
considered a “unicum hidrobiologicum” because of its physical, chemical, and
biological peculiarities; unlike any other sea. The Black Sea is permanently deficient in oxygen, or anoxic below a depth of 150–200 m (Bologa 1994). Major
factors contributing to the deterioration of the Black Sea environment are pollution
and improper use of natural resources (Osvath et al. 1998). The Black Sea is a
unique marine environment, one especially exposed to anthropogenic impact.
Almost landlocked, besides the link with the shallow inland Azov Sea, its only
exchange of water with the World Ocean is through the narrow Bosporus Strait.
As to radioactive contamination, different IAEA programmes showed that
concentration of anthropogenic radionuclides in the Black sea environment,
300
A. Strezov