THE ROLE OF THE ZEBRA MUSSEL, DREISSENA-POLYMORPHA, IN CONTAMINANT CYCLING .2. ZEBRA MUSSEL CONTAMINANT ACCUMULATION FROM ALGAE AND SUSPENDED PARTICLES, AND TRANSFER TO THE BENTHIC INVERTEBRATE, GAMMARUS-FASCIATUS
Ka. Bruner et al., THE ROLE OF THE ZEBRA MUSSEL, DREISSENA-POLYMORPHA, IN CONTAMINANT CYCLING .2. ZEBRA MUSSEL CONTAMINANT ACCUMULATION FROM ALGAE AND SUSPENDED PARTICLES, AND TRANSFER TO THE BENTHIC INVERTEBRATE, GAMMARUS-FASCIATUS, Journal of Great Lakes research, 20(4), 1994, pp. 735-750
To determine the contribution of ingested material to zebra mussel con
taminant accumulation, contaminant assimilation efficiencies (fraction
of the total contaminant exposure that is accumulated into tissue, AE
) from spiked algae and suspended sediment particles were measured for
benzo(a)pyrene, the insecticide DDT, and selected polychlorinated bip
henyl (PCB) congeners. Contaminant transfer from zebra mussel feces to
the benthic invertebrate, Gammarus fasciatus, was determined by measu
ring AE from PCB contaminated mussel feces to gammarids. Further, muss
el contaminant AE values coupled with physiological and environmental
parameters were used in a steady-state model to examine the relative i
mportance of the algal, suspended sediment, and water-borne exposure r
outes for a representative organochlorine compound, hexachlorobiphenyl
(HCBP). The relative accumulation via the fecal and water exposure ro
utes were modeled for gammarids. Mussel AE values for contaminant accu
mulation were greater from algae than from suspended sediments. Model
estimates indicated that when contaminant concentrations in the water
were near detection limits, dietary exposure was the primary route of
contaminant accumulation (61.5% of the total contaminant concentration
). Water was the most important route of contaminant exposure (89.5% o
f the total contaminant concentration) when contaminant concentrations
in water were IO times greater than the compound detection limit. Sus
pended sediment was the major dietary source of contaminants at all wa
ter concentrations. % AE for zebra mussel feces to gammarid transfer w
ere high-79.0 and 89.4% for hexachlorobiphenyl and tetrachlorobiphenyl
respectively-but not statistically different. Model estimates indicat
ed that the dietary route of exposure was the primary source of PCB ex
posure for gammarids and indicated a potential for PCB biomagnificatio
n in the mussel-based detrital food chain. Results suggest that zebra
mussels have the potential to change contaminant cycling in the Great
Lakes by rerouting dissolved and particulate bound contaminants throug
h zebra mussel food chains with possible biomagnification in upper tro
phic levels.