|Title||A critical body residue approach for predicting persistent bioaccumulative toxicant effects on reproduction and population dynamics of meiobenthic copepods|
|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Chandler, GT, Ferguson, PL, Klauber, WW, Washburn, KM|
|Journal||Environmental Toxicology & Chemistry|
|Pagination||1076 - 1082|
Critical body residues (CBRs) are the measured tissue toxicant concentrations yielding a median dose-response on a dry-weight or lipid-normalized basis. They facilitate management decisions for species protection using tissue analysis. Population CBR is the mean dose yielding 50% population suppression and was predicted here in Amphiascus tenuiremis for fipronil sulfide (FS) using lifetables and the Leslie matrix. Microplate bioassays (ASTM E-2317-14) produced biomass sufficient for dry mass and lipid-normalized CBR estimates of reproduction (fertility) and population growth suppression. Significant FS toxic effects were delayed naupliar development (at ≥0.10μgL -1), delayed copepodite development (at 0.85μgL -1), decreased reproductive success (at ≥ 0.39μgL -1), and decreased offspring production (at 0.85μgL -1). A reproductive median effective concentration (EC50) of 0.16μgL -1 (95% CI: 0.12-0.21μgL -1) corresponded to an adult all-sex CBR and lipid-normalized CBR of 0.38pg FS·μg -1 dry weight (95% CI: 0.27-0.52pg FS·μg -1) or 2.8pg FS·μg -1 lipid (95% CI: 2.2-3.6pg FS·μg -1), respectively. Copepod log bioconcentration factor (BCF)=4.11±0.2. Leslie matrix projections regressed against internal dose predicted fewer than five gravid females in a population by the third generation at 0.39 and 0.85μg FS·L -1 (i.e., 9.6-10.2μg FS·μg -1 lipid), and 50% population suppression at a CBR of 1.6pg FS·μg -1 lipid. This more integrative population CBR as a management tool would fall 1.75 times below the CBR for the single most sensitive endpoint-fertility rate. © 2012 SETAC.
|Short Title||Environmental Toxicology & Chemistry|