Metal accumulation, filtration and O2 uptake rates in the mussel Perna perna (Mollusca: Bivalvia) exposed to Hg2+, Cu2+ and Zn2+

Tissue metal concentrations, filtration and oxygen uptake rates were investigated for Perna perna (Bivalvia: Mollusca) during exposure to Hg2+, Cu2+ and Zn2+ (50 mug/l for 24 days, and 24 days recovery with no metal). Hg and Cu tissue levels increased with exposure time, reaching maximum levels after 24 days (87.5 mug Hg/g dry mass and 45 mug Cu/g dry mass, respectively). Zn levels peaked after 4 days exposure (to 233 mug Zn/g dry mass) and stabilized thereafter. Accumulated metal was rapidly lost from tissues when mussels were returned to uncontaminated seawater, suggesting that tissue concentration data may be of limited use in biomonitoring situations where environmental metals fluctuate to low levels. Filtration rates fell below control rates during Hg2+ exposure, and became elevated again during the recovery period. Cu2+ and Zn2+ exposure had little effect on filtration, but suppressed oxygen uptake. During recovery, oxygen uptake of Cu2+ and Zn2+ exposed mussels was elevated above the controls. Filtration and oxygen uptake rates were not correlated, but rather responded in different ways to metal pollution. While these physiological responses of P perna may be of limited use in biomonitoring, they could indicate how populations may respond to marine pollution. (C) 2002 Elsevier Science Inc. All rights reserved.