Bioaccumulation of heavy metals by shrimp (Litopenaeus schmitti): A dose-response approach for coastal resources management

We reveal a dose-response relationship for bioaccumulation of Zn, Cu and Cr in shrimp Litopenaeus schmitti from Sepetiba Bay, Rio de Janeiro, Brazil. Our model estimates the current risk (AD50 was 70% of the legal limit) and the daily metal uptake rate for each metal. It can also evaluate the relative reliability of predictions for tissue concentrations reaching the legal limits for human consumption (approximately 1 year) and predictions related to asymptotic length, arising from (i) direct regression of the metal concentration (MeC) versus total length (TL) and age (duration of exposure), and (ii) correlation of the incorporation rate (IR = MeC/TL) with age. Metal incorporation rates (IR), i.e. a kinetic proxy for absorption during growth up to attainment of asymptotic length, decrease with age, reflecting a slow-down in metal absorption. This pattern mitigates the high initial concentrations observed for juveniles.