Table 3.

Correlation coefficients between metal pollution index (MPI) and biomarker responses of mussels from different sampling sites in Bulgaria, significant at p < 0.05 (N = 20).

Biometric indices/biomarker responses	Spearman's rang correlation coefficient
CI total	n.s.
CI 2	n.s.
CI 3	-0.824
CI 4	n.s.
CI 5	-0.592
CAT	0.745
GPx	0.718
GR	0.904
ChE	-0.710
ASAT	-0.760
ALAT	-0.772
LDH	n.s.
Tail intensity	0.953

n.s.: Non-significant.

CI total = weight of soft tissue (g)/total weight (g) x 100, CI 2 = weight of soft tissue (g)/shell weight (g) x 100, CI 3 (state index) = weight of soft tissue (g)/shell length (cm) x 100, CI 4 (shell component index) = shell weight (g)/(shell weight (g) + meat weight (g)) x 100, CI 5 (condition factor) = weight of soft tissue (g)/shell lengthˆ3 (mm) x 100.

ASAT – aspartate aminotransferase, ALAT – alanine aminotransferase, CAT – catalase, ChE – cholinesterase, GPx – glutathione peroxidase, GR – glutathione reductase, and LDH – lactate dehydrogenase in the digestive glands of caged mussels (U/mg protein).

Tail intensity (TI%) – average results of DNA damage (percentage of DNA in the tail of the comet) in the haemocytes of caged mussels.