• Final Report: BUI Delisting Studies in the Buffalo River AOC, 2014-2015

      Haynes, James M.; Wellman, Sara T.; Haynes, James M.; Wellman, Sara T.; Marsocci, Anthony R. (2016-05-16)
      Only two mink were caught during 4,157 trap-days of effort in the BR AOC during the fall of 2014. This result led to changing the focus of the study to determining mink habitat suitability and analysis of BUI chemicals of concern in mink prey. According to the USFWS Habitat Suitability Index Model, habitat in the BR AOC is poorly suited for mink. On a scale of 0 to 1, the HSI for mink is 0.38. No amphibians were observed in riparian habitats along the Buffalo River in the AOC during ~300 h of searching for them in August, October & November 2014 and April & July 2015. During 35 minnow trap-days in mid-November 2015 and ~6 h of snorkeling to overturn rocks in June and November 2015 combined, far too few crayfish to create three 70 g samples for chemical analyses were caught in the BR AOC. Lower trophic level (bluegill, pumpkin seed and yellow perch) and upper trophic level (large mouth bass) fish samples were composited and analyzed for total mercury, total PCB and total TEQ (sum of PAH REP, PCB TEQ and CDD/CDF TEQ). Among the six composited prey samples analyzed (three each of lower and upper trophic level fish) for BUI chemicals of concern, only three of the 24 analyses (4 chemicals * 6 samples) exceeded dietary LOAELs for mink: two upper trophic level fish samples for total PCB (by 8.4 and 20.1%) and one upper trophic level fish sample for PCB TEQ (by 1.4%). Mink are one of the most sensitive mammals to the chemicals analyzed, especially to TEQ concentrations of CDD/CDF and co-planar PCB congeners which have similar toxic effects. If mink living in the BR AOC ate only large mouth bass from the Buffalo River (the upper trophic level fish analyzed in this study), on average they would exceed the dietary LOAEL for total PCB by 3.6% and not exceed the dietary LOAELs for any of total mercury, PAH REP and TEQ for CDD/CDF and PCB. Since mink eat prey from multiple trophic levels, many at lower levels than large mouth bass, it is very unlikely that mink and other predatory wildlife and birds in the BR AOC are adversely affected by any of the BUI chemicals of concern. We estimated the potential dietary exposures of BR AOC mink to BUI chemicals of concern for both “worst-case” (trophic level 3.7 diet) and “typical-case” (trophic level 2.4 diet) dietary scenarios. Neither diet exceeded any of the dietary LOAELS for BUI contaminants in mink. The trophic levels of mink trapped in our previous RE AOC study, and the two mink trapped in this study, suggest that mink in the BR AOC are consuming diets with trophic levels well below that of our estimated “worst-case” diet, putting them at no increased risk for either deformities or reproductive problems. For the “Bird or Animal Deformities or Reproductive Problems” BUI, it would be reasonable to consider the delisting criteria relating to mink to be unimpaired in BR AOC because using a worst case diet scenario for mink and the analytically determined mean concentrations of BUI contaminants in potential prey a hazard assessment showed that the dietary LOAELs for the contaminants of concern would not be exceeded for mink. Because mink are highly sensitive to mercury and CDD/CDF/PCB TEQ, it is unlikely that other piscivorous wildlife and birds in the BR AOC would be adversely affected by consuming a worst-case mink diet.
    • Final Report: BUI Delisting Studies in the Niagara River AOC, 2014-2015

      Haynes, James M.; Wellman, Sara T.; Haynes, James M.; Wellman, Sara T.; Marsocci, Anthony R. (2016-09-26)
      From 8 December 2013 to 6 April 2015, 24 mink were caught in the Niagara River AOC, 12 upriver and 12 downriver from Niagara Falls. Average concentrations of total mercury in mink brain and PAH REP in mink liver were 22 and 201 times lower, respectively, than their LOAELs for deformities or reproductive impairment. The average concentration of total PCB in mink liver was 1.15 times higher than the LOAEL for deformities or reproductive impairment, but two mink (one caught upriver and one downriver from Niagara Falls) had very high concentrations of both total PCB and total TEQ (mostly comprised of PCB TEQ). Average concentrations of PCB TEQ and CDD/CDF TEQ in mink liver were 2.9 times higher and 2.9 times lower, respectively, than their LOAELs for deformities or reproductive impairment. The average concentration of total TEQ (sum of PCB, CDD/CDF and PAH) in mink liver was 3.3 times higher than the LOAEL for deformities or reproductive impairment. Mink are one of the most sensitive mammals to CDD/CDF and co-planar PCB congeners, and 67% of the mink trapped in the NR AOC exceeded one or both of the published LOAELs for deformities or reproductive impairment for total PCB and total TEQ. Yet mink are reasonably abundant in suitable habitats in the AOC; thus they are either reproducing there or migrating in from adjacent areas with lower contaminant exposures. The most sensitive biomarker of mink health after exposure to total PCB or total TEQ is the presence of pre-cancerous tissues associated with the jawbone. Of the nine mink with the highest total PCB or total TEQ concentrations, two (22%) had the mildest form and one (11%) had the most severe form of this condition. All of the affected mink were captured in the lower river below Niagara Falls. For the “Bird or Animal Deformities or Reproductive Problems” BUI, in terms of mink health in the NR AOC, it appears that the time for delisting is not yet at hand.
    • Final Report: BUI Delisting Studies in the Rochester Embayment AOC, 2013-2014

      Haynes, James M.; Wellman, Sara T. (2015-12-01)
      Substantial evidence of live mink was observed along the shoreline of the Genesee River portion of the RE AOC, which supports delisting the “mink are present and are reproducing” criterion of the Degradation of Fish and Wildlife Populations and the Loss of Fish and Wildlife Habitat BUIs. According to the USFWS Habitat Suitability Index Model, habitat appears to be highly suitable (85%) for mink along the Genesee River shoreline of the RE AOC, which supports delisting of the Loss of Fish and Wildlife Habitat BUI.For total mercury chemical analysis: a. No amphibian, crayfish and lower trophic level fish samples exceeded the published dietary lowest observed adverse effect level (LOAEL) for mink. b. All upper trophic level fish samples exceeded the published dietary LOAEL for mink (500 ng/g), by 13% on average. For PAH, PCB and dioxin (CDD)/furan (CDF) chemical analyses: a. None of the 12 composited mink prey samples exceeded dietary LOAELs for total PCBs (960,000 pg/g) and TEQ for CDD/CDF (9.2 pg/g). b. Ten of the 12 samples did not exceed the dietary LOAEL for PAHs, co-planar PCBs, and CDD/CDF combined (9.2 pg/g). c. One upper trophic level fish sample exceeded the dietary LOAEL for PAHs by 147% because it contained ~100 times more PAHs (which accounted for 95% of total TEQ in that sample) than the other two samples. d. One lower trophic level fish sample exceeded the dietary LOAEL for PCB TEQ by 4% because it contained ~90 times more PCB 126 (which accounted for 93% of total TEQ in that sample) than the other two samples. Mink hazard assessment: a. Using the “highest exposure” mink diet found in published literature (92% from aquatic sources), and using mean concentrations of BUI contaminants found in 2 potential mink prey in the Genesee River portion of the RE AOC, the maximum dietary exposure of mink would be 81% of the LOAEL for total mercury, 23% of the LOAEL for total PCBs, and 69% of the LOAEL for total TEQ (PAHs + CDD/CDF + co-planar PCBs). This is the “worst case” diet scenario. b. Using the average of six mink diets reported in published literature (65% from aquatic sources) comparable to what mink would eat in the Genesee River portion of the RE AOC, and using mean concentrations of BUI contaminants found in potential mink prey in the study area, the dietary exposure of mink would be 48% of the LOAEL for total mercury, 13% of the LOAEL for total PCBs, and 40% of the LOAEL for total TEQ. This is the “likely” diet scenario. It would be reasonable to delist the Bird or Animal Deformities or Reproductive Problems BUI in the RE AOC because: a. Except for total mercury (13% above) and total TEQ (3.4% below; CDD/CDF, PAH and co-planar PCB TEQ combined) in upper trophic level fish, mean concentrations of BUI contaminants in the other three mink prey groups (crayfish, amphibians, lower trophic level fish) were far below dietary LOAELs for mink. b. Using a worst case diet (92% aquatic) for mink, and the analytically-determined mean concentrations of BUI contaminants in potential prey, a hazard assessment showed that the dietary LOAELs for total mercury, total PCBs, and total TEQ would not be exceeded for mink in the Genesee River portion of the RE AOC.