MUGIL CEPHALUS BIOINDICATORE DEL CARICO ANTROPICO DI ALCUNI METALLI PESANTI NEL LAGO DI FARO: INFLUENZA STAGIONALE E MONITORAGGIO DEI “BLOOD BIOMARKERS"

The aim of this study was: 1) to evaluate in striped mullet Mugil cephalus (Linnaeus, 1758), a sentinel fish species captured exposed to heavy metal pollution, the capacity of bioaccumulation in different tissues and organs. 2) to determine the seasonal variations in the concentration of some heavy metals (cadmium Cd; Lead Pb; chromium Cr and mercury Hg) in different tissues (muscle, gills, liver, stomach and intestine) of this species. 3) to evaluate haematological and haematochemical response of fish in relation to the different bioaccumulation of metals in different season, in order to identify possible blood biomarkers useful to biomonitoring the aquatic environment exposed to heavy metal pollution. For this purpose, 80 M. cephalus (20 for each season) were captured in three different stations of Faro Lake, Messina, Sicily. Biometric indices (weight, fork length and total length) of each fish were registered. The physico-chemical parameters of the water of the study area were also measured and the content of heavy metal in water and sediment was determined. On all fish, haematological (white blood cell, WBC; red blood cell, RBC; haemoglobin concentration, Hb; haematocrit, Hct; mean corpuscular volume, MCV; mean corpuscular haemoglobin, MCH; mean corpuscular haemoglobin concentration, MCHC; thrombocytes count, TC), haematochemical parameters (aspartate aminotransferase, AST; alanine aminotransferase, ALT; alkaline phosphatase, ALP; lactate dehydrogenase, LDH) and the concentration of heavy metals in different tissues in the four seasons were assessed. Our results showed that different tissues of M. cephalus have a different heavy metal bioaccumulation capacity; gills were the tissue with the highest concentration of metals while the muscle with the lowest. The results of statistical analysis of the data, after the application of one-way analysis of variance (ANOVA) showed statistically significant differences in the haematological, haematochemical parameters and in the tissue concentration of heavy metals in the different seasons. Our research provides a valid contribute to techniques concerning environmental biomonitoring and, therefore, to the control of pollution and water management, it also contributes to expanding the studies, carried out to date in this field, to improve the health and sustainability of aquatic environments.