Jeffry Bernardy | Geology Reports

USGS2020

Distribution of niclosamide following granular Bayer applications in lentic environments

Temporal and spatial distribution of niclosamide in the water column and sediment were evaluated after the application of granular Bayluscide in six lentic sea lamprey ( Petromyzon marinus ) larval assessment plots. Water and sediment were collected 0.25, 1, 3, 5, and 7 hours after application and were analyzed for niclosamide, the active ingredient in granular Bayluscide. Water samples were collected from five heights in the water column (1 cm, 13 cm, 26 cm, 1/2 water column, and water surface) at five locations inside and four locations 10 m outside of each assessment plot. Sediment was collected from 18 locations within each plot. Niclosamide water concentrations inside and outside of the plots did not vary by depth but did vary between plots and by time. Niclosamide water concentrations also varied by sampler location outside of the plots. Following granular Bayluscide applications the mean niclosamide concentration in water for all levels, within the plots, decreased from 0.12 mgL -1 (SD = 0.12 mgL -1 ) at 15 minutes to 0.061 mgL -1 (SD = 0.040 mgL -1 ) at hour 1. The mean niclosamide concentration in the top 4 cm of sediment was 2.9 mgkg -1 (SD = 2.4 mgkg -1 ) 15 minutes after application and was 1.3 mgkg -1 (SD = 1.8 mgkg -1 ) at hour 7. Concentrations in all sediment samples ranged from < 0.001 to 30.730 mgkg -1 and varied between the six plots. Niclosamide concentrations measured in sediment samples were more than 1 order of magnitude greater than in the water and varied spatially by over 4 orders of magnitude.

Michigan, Wisconsin↗

USGS2020

Lampricide residues in sea lamprey larvae carcasses recovered after 3-trifluoromethyl-4- nitrophenol (TFM) or TFM/Bayluscide stream treatments

Lampricide concentrations in whole larval sea lamprey ( Petromyzon marinus ) carcasses collected after lampricide treatments were determined to support risk assessment for non-target organisms that may consume lampricide-laden carcasses. Dead larvae were collected by Sea Lamprey Control personnel following the Ford River (Delta County, Michigan) 4.1 mg·L -1 3-trifluoromethyl-4-nitrophenol (TFM) treatment, Sturgeon River (Baraga County, Michigan) 0.64 mg·L -1 /7.1 µg·L -1 TFM/niclosamide treatment, and two treatments on the Chippewa River (Isabella County, Michigan). The upper reach of the Chippewa River was treated with 3.1 mg·L -1 /33 µg·L -1 TFM/Bayluscide and the lower reach was treated with 4.1 mg·L -1 TFM. Carcasses were removed from each stream via scap nets immediately after treatment completion. To assess instream degradation, half of the collected carcasses from both Chippewa River treatments were placed in cages and returned to the river for 2 days before they were analyzed for lampricide residues. The estimated mean and standard error of the mean (SEM) TFM concentration in the fresh carcasses (n = 80) collected from all the TFM and TFM/Bayluscide treated rivers was 4.6 µg·g -1 (SEM =1.1 µg·g -1 ). The mean concentration of niclosamide (the active ingredient in Bayluscide) in the fresh carcasses (n = 40) from the two rivers treated with TFM/ Bayluscide was 0.49 µg·g -1 (SEM = 0.21 µg·g -1 ). The mean 2-day postmortem carcasses from the Chippewa River TFM/Bayluscide treatment contained 0.14 µg·g -1 (3%) of the TFM and 0.41 µg·g -1 (64%) of the niclosamide found in the fresh-carcass group (4.4 µg·g -1 TFM and 0.64 µg·g -1 niclosamide). The mean 2-day postmortem carcasses from the Chippewa River TFM treatment contained 0.72 µg·g -1 (12%) compared to the 6.1 µg·g -1 of TFM found in the fresh-carcass group.

Michigan↗