Baron Delʹvig; materīaly bīograficheskīe i literaturnye,

Bio-bibliographical notes included in "Primi︠e︡chanīi︠a︡" (p. [99]-[116])Stikhotvorehīi︠a︡ i statʹi barona Delʹviga.--Pisʹma i offit︠s︡īalʹnyi︠a︡ bumagi barona Delʹviga.--Pisʹma raznykh lit︠s︡ i dokumenty, kasai︠u︡shchīesi︠a︡ barona Delʹviga.--Iz kommentarīev k stikhotvorehīi︠a︡m barona Delʹviga.Mode of access: Internet

Si͡evernye t͡si͡ety [microform]

Edited by A. Delʹvig and O. Somov.Microfilm.Mode of access: Internet

Correction: Potential of Environmental DNA to Evaluate Northern Pike (Esox lucius) Eradication Efforts: An Experimental Test and Case Study.

[This corrects the article DOI: 10.1371/journal.pone.0162277.]

Data from: Potential of environmental DNA to evaluate Northern pike (Esox lucius) eradication efforts: an experimental test and case study

Determining the success of invasive species eradication efforts is challenging because populations at very low abundance are difficult to detect. Environmental DNA (eDNA) sampling has recently emerged as a powerful tool for detecting rare aquatic animals; however, detectable fragments of DNA can persist over time despite absence of the targeted taxa and can therefore complicate eDNA sampling after an eradication event. This complication is a large concern for fish eradication efforts in lakes since killed fish can sink to the bottom and slowly decay. DNA released from these carcasses may remain detectable for long periods. Here, we evaluated the efficacy of eDNA sampling to detect invasive Northern pike (Esox lucius) following piscicide eradication efforts in southcentral Alaskan lakes. We used field observations and experiments to test the sensitivity of our Northern pike eDNA assay and to evaluate the persistence of detectable DNA emitted from Northern pike carcasses. We then used eDNA sampling and traditional sampling (i.e., gillnets) to test for presence of Northern pike in four lakes subjected to a piscicide-treatment designed to eradicate this species. We found that our assay could detect an abundant, free-roaming population of Northern pike and could also detect low-densities of Northern pike held in cages. For these caged Northern pike, probability of detection decreased with distance from the cage. We then stocked three lakes with Northern pike carcasses and collected eDNA samples 7, 35 and 70 days post-stocking. We detected DNA at 7 and 35 days, but not at 70 days. Finally, we collected eDNA samples ~ 230 days after four lakes were subjected to piscicide-treatments and detected Northern pike DNA in 3 of 179 samples, with a single detection at each of three lakes, though we did not catch any Northern pike in gillnets. Taken together, we found that eDNA can help to inform eradication efforts if used in conjunction with multiple lines of inquiry and sampling is delayed long enough to allow full degradation of DNA in the water

Potential of Environmental DNA to Evaluate Northern Pike (Esox lucius) Eradication Efforts: An Experimental Test and Case Study.

Determining the success of invasive species eradication efforts is challenging because populations at very low abundance are difficult to detect. Environmental DNA (eDNA) sampling has recently emerged as a powerful tool for detecting rare aquatic animals; however, detectable fragments of DNA can persist over time despite absence of the targeted taxa and can therefore complicate eDNA sampling after an eradication event. This complication is a large concern for fish eradication efforts in lakes since killed fish can sink to the bottom and slowly decay. DNA released from these carcasses may remain detectable for long periods. Here, we evaluated the efficacy of eDNA sampling to detect invasive Northern pike (Esox lucius) following piscicide eradication efforts in southcentral Alaskan lakes. We used field observations and experiments to test the sensitivity of our Northern pike eDNA assay and to evaluate the persistence of detectable DNA emitted from Northern pike carcasses. We then used eDNA sampling and traditional sampling (i.e., gillnets) to test for presence of Northern pike in four lakes subjected to a piscicide-treatment designed to eradicate this species. We found that our assay could detect an abundant, free-roaming population of Northern pike and could also detect low-densities of Northern pike held in cages. For these caged Northern pike, probability of detection decreased with distance from the cage. We then stocked three lakes with Northern pike carcasses and collected eDNA samples 7, 35 and 70 days post-stocking. We detected DNA at 7 and 35 days, but not at 70 days. Finally, we collected eDNA samples ~ 230 days after four lakes were subjected to piscicide-treatments and detected Northern pike DNA in 3 of 179 samples, with a single detection at each of three lakes, though we did not catch any Northern pike in gillnets. Taken together, we found that eDNA can help to inform eradication efforts if used in conjunction with multiple lines of inquiry and sampling is delayed long enough to allow full degradation of DNA in the water

Raw_data

Quantification cycle values and scores for Northern pike DNA in water samples collected at multiple lakes across time

Schematic of the locations of eDNA sampling.

<p>Locations of pre (○)and post (●)-rotenone treatments are identified in Derks, East Mackey, Union, and West Mackey Lakes near Soldotna, AK. Post-treatment samples were collected at all pre-treatment sample locations. The background base map is exclusive property of Environmental Systems Research Institute, Inc. (Esri).</p

Schematic of the locations of Northern pike cages relative to eDNA sampling locations.

<p>Northern pike carcass locations were identical to cage locations in Tiny, Gensle, Little Bear, and Denise lakes near Soldotna, AK. The background base map is exclusive property of Environmental Systems Research Institute, Inc. (Esri).</p

Physical habitat and fish stocking data for caged and carcass experiments.

<p>Physical habitat and fish stocking data for caged and carcass experiments.</p