Seasonal variability in biomarkers in the bivalves Mytilus edulis and Macoma balthica from the northern Baltic Sea

Indices for the assessment of environmental pollution of the Baltic Sea coasts: Integrated assessment of a multi-biomarker approach

“…In the Baltic Sea the blue mussel usually reproduces between late spring and mid-summer, sometimes showing a second spawning peak in late summer (Kautsky, 1982). In the mussel and the soft-bottom clam Macoma balthica elevated levels of biomarkers (AChE, GST, catalase and MT) and the resulting IBR have been recorded during the reproductive period in the northern Baltic Sea (Leiniö and Lehtonen, 2005), corresponding with the results obtained in the present study.…”

“…In the original version of Beliaeff and Burgeot (2002) the order of biomarkers within the data sets used in the calculation of Star Plot areas was fixed, randomly or intentionally, ignoring the obvious problem of obtaining different values with different biomarker arrangements. In the modification applied here (Leiniö and Lehtonen, 2005;Lehtonen et al, in press) several IBRs were calculated from the same data changing the order of the biomarkers and using the mean ± SD of all the index values as the final index value. As one might expect the SD of mean becomes smaller as the number of biomarkers increases, illustrating that the order of the biomarkers in the calculation process does not play any notable role when their number is sufficiently large.…”

A multibiomarker approach in the clam Ruditapes decussatus to assess the impact of pollution in the Ria Formosa lagoon, South Coast of Portugal

“…Moreover, ALAD activity varied negatively with temperature and AChE with salinity and dissolved oxygen, and this has already been pointed out by others authors in different bivalve species (Dellali et al, 2001;Pfeifer et al, 2005). It is also known that AChE is directly affected by temperature (Dellali et al, 2001;Leiniö and Lehtonen, 2005;Pfeifer et al, 2005). In the present work, no significant correlation was found between this biomarker and temperature (p > 0.05), but the lowest mean AChE activity was at site 4, where the mean temperature was also lowest (Table 2).…”

“…The high temporal variability of biomarkers, with higher responses in summer can thus be strengthened by the influence of environ--mental parameters (e.g. higher seawater temperature, solar irra--diance, oxygen decrease) that could induce higher physiological stress as already observed for other bivalve species (Andrès et al, 1999;Baudrimont et al, 1997;Bocchetti and Regoli, 2006;Bocchetti et al, 2008;Leiniö and Lehtonen, 2005). Additionally, oxidative damage such as lipid peroxidation or DNA damage can be triggered and produce detrimental effects on the physiological status of clams (Bocchetti and Regoli, 2006;Bocchetti et al, 2008;Sobral and Widdows, 1997).…”

“…Therefore, to overcome this drawback and integrate the data as a whole, a PCA was conducted. In ecosystems like the Ria Formosa lagoon, where contamination is not particularly high, seasonal factors such as severe environmental parameters (Table 2) have an important effect on biomarkers response (Leiniö and Lehtonen, 2005;Orbea et al, 2002), as reflected by the correlation between biomarkers and environmental conditions for the global studied period (Fig. 2).…”