Body size-dependent Cd accumulation in the zebra mussel Dreissena polymorpha from different routes.
Understanding body size-dependent metal accumulation in aquatic organisms (i.e., metal allometry) is critical in interpreting biomonitoring data. While growth has received the most attention, little is known about controls of metal exposure routes on metal allometry. Here, size-dependent Cd accumulation in zebra mussels (Dreissena polymorpha) from different routes were investigated by exposing mussels to A.(111Cd spiked algae+113Cd spiked river water) or B.(111Cd spiked sediments+113Cd spiked river water). After exposure,111Cd or113Cd levels in mussel tissue were found to be negatively correlated with tissue weight, while Cd allometry coefficients (b values) were dependent on Cd exposure routes: -0.664 for algae, -0.241 for sediments and -0.379 for river water, compared to -0.582 in un-exposed mussels. By comparing different Cd exposure routes, we found that size-dependent Cd bioaccumulation from algae or river water could be more responsible for the overall size-dependent Cd accumulation in mussels, and the relative importance of the two sources was dependent on mussel size ranges: Cadmium obtained from algae (algae-Cd) was more important in size-dependent Cd accumulation in smaller mussels (tissue dry weight < 5 mg), while river water-Cd became more important in larger individuals (tissue dry weight > 5 mg). In contrast, sediment-Cd contributed only a small amount to Cd accumulation in zebra mussels and may have little effect on size-dependent Cd bioaccumulation. Our results suggest that size-dependent Cd accumulation in mussels could be largely affected by exposure routes, which should be considered when trying to interpret Cd biomonitoring data of zebra mussels.
School of Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, People's Republic of China. Electronic address: melody102@163.com.
Wen-Li
WL
Tang
Environmental and Resource Studies Program (ERS), Trent University, Peterborough, Ontario, Canada; School of Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, People's Republic of China. Electronic address: devans@trentu.ca.
Douglas
D
Evans
Environmental and Resource Studies Program (ERS), Trent University, Peterborough, Ontario, Canada. Electronic address: lisakraemer@trentu.ca.
Lisa
L
Kraemer
School of Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, People's Republic of China; Environmental and Life Sciences Program (EnLS), Trent University, Peterborough, Ontario, Canada. Electronic address: huanzhong@trentu.ca.
Huan
H
Zhong
D000818:Animals; D049628:Body Size; D002104:Cadmium / Q000032:analysis / Q000378:metabolism*; D000460:Chlorophyta / Q000737:chemistry*; D049875:Dreissena / Q000254:growth & development* / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*
D002104:Cadmium
Algae; Allometry; Bioaccumulation; Cadmium; Sediment; Zebra mussel