Dynamic energy budget as a basis to model population-level effects of zinc-spiked sediments in the gastropod Valvata piscinalis.
This paper presents original toxicity test designs and mathematical models that may be used to assess the deleterious effects of toxicants on Valvata piscinalis (Mollusca, Gastropoda). Results obtained for zinc, used as a reference toxicant, are presented. The feeding behavior, juvenile survival, growth, age at puberty, onset of reproduction, number of breedings during the life cycle, and fecundity were significantly altered when the snails were exposed to zinc-spiked sediments. Dynamic energy budget models (DEBtox) adequately predicted the effects of zinc on the V. piscinalis life cycle. They also provided estimates for lifecycle parameters that were used to parameterize a demographic model, based on a Z-transformed life-cycle graph. The effect threshold for the population growth rate (lambda) was estimated at 259 mg/kg dry sediment of zinc, showing that significant changes in abundance may occur at environmental concentrations. Significant effects occurring just above this threshold value were mainly caused by the severe impairment of reproductive endpoints. Sensitivity analysis showed that the value of lambda depended mainly on the juvenile survival rate. The impairment of this latter parameter may result in extinction of V. piscinalis. Finally, the present study highlights advantages of the proposed modeling approach in V. piscinalis and possible transfer to other test species and contaminants.
Ducrot
Virginie
V
Laboratoire d'écotoxicologie, Cemagref, 3bis quai Chauveau, CP 220, F-69336 Lyon Cedex 09, France. virginie.ducrot@rennes.inra.fr
Péry
Alexandre R R
AR
Mons
Raphaël
R
Quéau
Hervé
H
Charles
Sandrine
S
Garric
Jeanne
J
D000818:Animals; D004305:Dose-Response Relationship, Drug; D049851:Gastropoda / Q000187:drug effects* / Q000254:growth & development; D019015:Geologic Sediments / Q000737:chemistry*; D008018:Life Cycle Stages / Q000187:drug effects* / Q000502:physiology; D008954:Models, Biological; D008962:Models, Theoretical; D011158:Population Growth; D013997:Time Factors; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*; D015032:Zinc / Q000378:metabolism / Q000633:toxicity*
D014874:Water Pollutants, Chemical; D015032:Zinc