Response of biomarkers to metals, hydrocarbons and organochlorine pesticides contamination in crabs (Callinectes ornatus and C. bocourti) from two tropical estuaries (São José and São Marcos bays) of the Maranhão State (northeastern Brazil).

Response of biomarkers to chemical contamination was evaluated in crabs of the Callinectes genus (Callinectes ornatus and C. bocourti) from two tropical estuaries (Sao Jose and Sao Marcos bays) of the Maranhao State (northeastern Brazil). Biomarkers evaluated included hepatopancreatic metallothionein-like proteins (MTLP) and lipid peroxidation (LPO), as well as muscle acetylcholinesterase (AChE). Tissue concentrations of metals (pereiopod muscle and hepatopancreas), hydrocarbons (hepatopancreas) and organochlorine pesticides (hepatopancreas) were also evaluated. Crab samples were collected in three sites of each estuary (Sao Marcos Bay and Sao Jose Bay). Sampling was performed in August/2012 (dry season), January/2013 (rainy season), August/2013 (dry season), and January/2014 (rainy season). Concentrations of chemical contaminants and responses of biomarkers showed significant spatial (Sao Marcos Bay and Sao Jose Bay) and/or seasonal (dry and rainy seasons) and annual (2012-2014) variability. However, a general higher Zn concentration was observed in hepatopancreas of crabs from Sao Jose Bay. In turn, a general higher Cd concentration paralleled by oxidative damage (LPO) was observed in hepatopancreas of crabs from Sao Marcos Bay. As expected, these findings support the idea that this bay is more intensively or chronically impacted by industrial activities while the Sao Jose Bay is likely more affected by domestic activities. Interestingly, LPO level in crab hepatopancreas showed to be the most reliable and adequate biomarker to distinguish the two bays.