in Ulva. Significant positive correlation coefficient (synergistic interaction between
HM) was obtained only for the pair Fe–Mn in Enteromorpha while negative
correlation (antagonistic) was obtained for Cu–Cd in Ulva. These correlation
coefficients differ from unit and therefore the correlation dependence is not clearly
expressed, meaning that the variables are connected but with weak functional
dependence.
If we assess the obtained algae data depending on the chemical nature of the HM,
the obtained tree diagram clearly separates Fe and Cu while Pb and Cd are strongly
linked which is clear as these two elements belong to one and the same group of the
Periodic table (Fig. 18.10).
Data were obtained for Fe, Mn, Cu, Pb and Cd content in the most widespread
Black Sea green macroalgae for the period 1996–2003 (Figs. 18.11, 18.12, 18.13,
18.14 and 18.15) HM environmental behavior in the marine environment of eight
locations (Shabla, Tuzlata, Kaliakra, Ravda, Rossenetz, Ahtopol, Sinemoretz,
Rezovo), distributed along the whole Bulgarian coast, has been studied. All
obtained results prove the dependence of toxic metal accumulation on green
algae species as well as on the location (Fig. 18.16).
It can be concluded that Fe, Mn, Cu, Pb and Cd concentration in Black Sea green
macroalgae decrease during the studied period. U. rigida species accumulate the
lowest concentrations of the studied metals. The highest Fe, Mn, Pb and Cd content
has been measured in macrophytes from Tuzlata and Rezovo. High Cu concentration is observed in the southern coastal area – Ahtopol and Sinemoretz (the highest
at Rossenetz).
All Black Sea green algae data are subjected to cluster analysis for all toxic
metal accumulation. The obtained tree diagram for all HM (Fig. 18.17) shows that
the algae are combined in two main groups plus C. coleothrix. The first main group
consist of Ulva and Bryopsis linked by Chaetomorpha. The second group is
Enteromorpha and C. vagabunda.
If the cluster analysis is performed for the toxic elements Cu, Pb and Cd, again
two main groups are obtained – first group containing C. coleothrix and
Chaetomorpha. The second group is divided in two – Enteromorpha, Bryopsis,
C. vagabunda linked with Ulva. The main influence on these clusters is due to the
presence of Cu because if we exclude Cu from the cluster process the obtained tree
diagrams are less affected.
If the obtained algae data are assessed depending on the chemical nature of the
HM, the obtained tree diagram clearly separates Fe and Cu while Pb and Cd are
strongly linked which is understandable as these two elements belong to one and the
same group of the Periodic table.
In conclusion it can be pointed out that Chlorophyta and Rhodophyta algae phyla
can be used as bioindicators for monitoring of the ecological state of the Black Sea
environment. A comparative analysis of contaminants in different Bulgarian coastline regions leads to the conclusions that the data obtained for red and green
macroalgae illustrate the level of contamination by HM and nuclides at seven
locations of the Black Sea Coast.
18 Radioecology of the Black Sea
323
HM) was obtained only for the pair Fe–Mn in Enteromorpha while negative
correlation (antagonistic) was obtained for Cu–Cd in Ulva. These correlation
coefficients differ from unit and therefore the correlation dependence is not clearly
expressed, meaning that the variables are connected but with weak functional
dependence.
If we assess the obtained algae data depending on the chemical nature of the HM,
the obtained tree diagram clearly separates Fe and Cu while Pb and Cd are strongly
linked which is clear as these two elements belong to one and the same group of the
Periodic table (Fig. 18.10).
Data were obtained for Fe, Mn, Cu, Pb and Cd content in the most widespread
Black Sea green macroalgae for the period 1996–2003 (Figs. 18.11, 18.12, 18.13,
18.14 and 18.15) HM environmental behavior in the marine environment of eight
locations (Shabla, Tuzlata, Kaliakra, Ravda, Rossenetz, Ahtopol, Sinemoretz,
Rezovo), distributed along the whole Bulgarian coast, has been studied. All
obtained results prove the dependence of toxic metal accumulation on green
algae species as well as on the location (Fig. 18.16).
It can be concluded that Fe, Mn, Cu, Pb and Cd concentration in Black Sea green
macroalgae decrease during the studied period. U. rigida species accumulate the
lowest concentrations of the studied metals. The highest Fe, Mn, Pb and Cd content
has been measured in macrophytes from Tuzlata and Rezovo. High Cu concentration is observed in the southern coastal area – Ahtopol and Sinemoretz (the highest
at Rossenetz).
All Black Sea green algae data are subjected to cluster analysis for all toxic
metal accumulation. The obtained tree diagram for all HM (Fig. 18.17) shows that
the algae are combined in two main groups plus C. coleothrix. The first main group
consist of Ulva and Bryopsis linked by Chaetomorpha. The second group is
Enteromorpha and C. vagabunda.
If the cluster analysis is performed for the toxic elements Cu, Pb and Cd, again
two main groups are obtained – first group containing C. coleothrix and
Chaetomorpha. The second group is divided in two – Enteromorpha, Bryopsis,
C. vagabunda linked with Ulva. The main influence on these clusters is due to the
presence of Cu because if we exclude Cu from the cluster process the obtained tree
diagrams are less affected.
If the obtained algae data are assessed depending on the chemical nature of the
HM, the obtained tree diagram clearly separates Fe and Cu while Pb and Cd are
strongly linked which is understandable as these two elements belong to one and the
same group of the Periodic table.
In conclusion it can be pointed out that Chlorophyta and Rhodophyta algae phyla
can be used as bioindicators for monitoring of the ecological state of the Black Sea
environment. A comparative analysis of contaminants in different Bulgarian coastline regions leads to the conclusions that the data obtained for red and green
macroalgae illustrate the level of contamination by HM and nuclides at seven
locations of the Black Sea Coast.
18 Radioecology of the Black Sea
323