Experimental Observations on the decay of Environmental DNA from Bighead and Silver Carp-Data
공공데이터포털
Interest in the field of environmental DNA (eDNA) is growing rapidly and eDNA surveys are becoming an important consideration for aquatic resource managers dealing with invasive species. However, in order for eDNA monitoring to mature as a research and management tool, there are several critical knowledge gaps that must be filled. One such gap is the fate of eDNA materials in the aquatic environment. Understanding the environmental factors that influence the decay of eDNA and how these factors impact detection probabilities over time and space could have significant implications for eDNA survey design and data interpretation. Here we experimentally explore eDNA decay in waste materials and reproductive cells obtained from captive stocks of the invasive bigheaded carps, Hypophthalmichthys nobilis and H. molitrix, as well as the influence of differing levels of water turbulence, temperature, microbial load, and pH on rates of eDNA decay. We found that the decay patterns of eDNA associated with both H. nobilis biological waste and H. molitrix milt significantly fit monophasic exponential decay curves. Secondly, we observed that the highest temperature we tested resulted in decay half-life as much as 5.5X more rapid than the lowest temperature we tested. When we suppressed microbial loads in eDNA samples, we observed that overall losses of eDNA were reduced by about 2.5X. When we amended eDNA samples with pond water the half-life of eDNA was reduced by about 2.25X, despite relatively little apparent increase in the overall microbial load, indicating the microbial sources, not only loads, might play a critical role in eDNA degradation. A shift in pH from 6.5 to 8.0 in the samples resulted in a 1.6X reduction in eDNA half-life. Water turbulence in our study had no apparent effect on eDNA decay. When we combined different temperature, pH, and microbial load treatments to create a rapid decay conditions and a slow decay conditions, and tracked eDNA decay over 91 days, we observed a 5.0X greater loss of eDNA by Day 5 under rapid decay conditions than under slow decay conditions. At the end of the trials, the differences in eDNA loss between the rapid decay and baseline and slow decay conditions were 0.1X and 3.3X, respectively. Our results strongly demonstrate the potential for environmental factors to influence eDNA fate, and thus the interpretation of eDNA survey results.
Experimental Observations on the decay of Environmental DNA from Bighead and Silver Carp-Data
공공데이터포털
Interest in the field of environmental DNA (eDNA) is growing rapidly and eDNA surveys are becoming an important consideration for aquatic resource managers dealing with invasive species. However, in order for eDNA monitoring to mature as a research and management tool, there are several critical knowledge gaps that must be filled. One such gap is the fate of eDNA materials in the aquatic environment. Understanding the environmental factors that influence the decay of eDNA and how these factors impact detection probabilities over time and space could have significant implications for eDNA survey design and data interpretation. Here we experimentally explore eDNA decay in waste materials and reproductive cells obtained from captive stocks of the invasive bigheaded carps, Hypophthalmichthys nobilis and H. molitrix, as well as the influence of differing levels of water turbulence, temperature, microbial load, and pH on rates of eDNA decay. We found that the decay patterns of eDNA associated with both H. nobilis biological waste and H. molitrix milt significantly fit monophasic exponential decay curves. Secondly, we observed that the highest temperature we tested resulted in decay half-life as much as 5.5X more rapid than the lowest temperature we tested. When we suppressed microbial loads in eDNA samples, we observed that overall losses of eDNA were reduced by about 2.5X. When we amended eDNA samples with pond water the half-life of eDNA was reduced by about 2.25X, despite relatively little apparent increase in the overall microbial load, indicating the microbial sources, not only loads, might play a critical role in eDNA degradation. A shift in pH from 6.5 to 8.0 in the samples resulted in a 1.6X reduction in eDNA half-life. Water turbulence in our study had no apparent effect on eDNA decay. When we combined different temperature, pH, and microbial load treatments to create a rapid decay conditions and a slow decay conditions, and tracked eDNA decay over 91 days, we observed a 5.0X greater loss of eDNA by Day 5 under rapid decay conditions than under slow decay conditions. At the end of the trials, the differences in eDNA loss between the rapid decay and baseline and slow decay conditions were 0.1X and 3.3X, respectively. Our results strongly demonstrate the potential for environmental factors to influence eDNA fate, and thus the interpretation of eDNA survey results.
Taxonomic composition of environmental DNA acquired by filtration from the St. Regis River, New York
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Environmental DNA (eDNA) surveys have become important tools for monitoring aquatic biodiversity. Barcode sequencing of eDNA generates community profiles that, while potentially biased in both capture and amplification, can nonetheless yield high information content per unit cost. While factors affecting eDNA capture and amplification have been heavily studied, watershed-scale assessments of fish communities and our confidence in such have been less frequent. We performed an initial watershed-scale characterization of fish eDNA using rapid, low-volume filtering with replicate and control samples scaled for a single Illumina MiSeq flow cell, using the mitochondrial 12S ribosomal RNA locus for taxonomic profiling. Our bioinformatic approach included 1) direct estimation of sequencing error from unambiguous mappings (alignments) and simulation of error in taxonomic assignment under various mapping criteria; 2) binning of species based on inferred assignment error rather than by taxonomic rank; and 3) visualization of mismatch distributions to facilitate discovery of distinct haplotypes attributed to the same reference. Our approach was implemented for the St. Regis River, New York, United States, which supports a valuable recreational fishery and has been a target of restoration activities. We used a large record of St. Regis-specific observations to validate our assignments. We found that 300 mL drawn through 25-mm filters yielded greater than 5 ng/µL DNA at most sites in August and September, which was an approximate threshold for generating strong sequencing libraries in our hands. Using inferred sequence error rates, we binned 12S references for 110 species on a state-level checklist into 85 single-species bins and seven multispecies bins. Of 48 taxonomic bins actually observed in the St. Regis, we detected eDNA consistent with 40, with an additional four detections flagged as potential contaminants post-collection. Sixteen unobserved species detected by eDNA ranged from plausible to implausible based on distributional data, whereas six observed species had no 12S reference sequence.
Taxonomic composition of environmental DNA acquired by filtration from the St. Regis River, New York
공공데이터포털
Environmental DNA (eDNA) surveys have become important tools for monitoring aquatic biodiversity. Barcode sequencing of eDNA generates community profiles that, while potentially biased in both capture and amplification, can nonetheless yield high information content per unit cost. While factors affecting eDNA capture and amplification have been heavily studied, watershed-scale assessments of fish communities and our confidence in such have been less frequent. We performed an initial watershed-scale characterization of fish eDNA using rapid, low-volume filtering with replicate and control samples scaled for a single Illumina MiSeq flow cell, using the mitochondrial 12S ribosomal RNA locus for taxonomic profiling. Our bioinformatic approach included 1) direct estimation of sequencing error from unambiguous mappings (alignments) and simulation of error in taxonomic assignment under various mapping criteria; 2) binning of species based on inferred assignment error rather than by taxonomic rank; and 3) visualization of mismatch distributions to facilitate discovery of distinct haplotypes attributed to the same reference. Our approach was implemented for the St. Regis River, New York, United States, which supports a valuable recreational fishery and has been a target of restoration activities. We used a large record of St. Regis-specific observations to validate our assignments. We found that 300 mL drawn through 25-mm filters yielded greater than 5 ng/µL DNA at most sites in August and September, which was an approximate threshold for generating strong sequencing libraries in our hands. Using inferred sequence error rates, we binned 12S references for 110 species on a state-level checklist into 85 single-species bins and seven multispecies bins. Of 48 taxonomic bins actually observed in the St. Regis, we detected eDNA consistent with 40, with an additional four detections flagged as potential contaminants post-collection. Sixteen unobserved species detected by eDNA ranged from plausible to implausible based on distributional data, whereas six observed species had no 12S reference sequence.
Environmental DNA (eDNA) is an Effective Tool to Track Recolonizing Migratory Fish Following Large-Scale Dam Removal, field data
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We collected environmental DNA (eDNA) data from the Elwha River, home to the world’s largest dam removal project, to track the spatial and temporal patterns of species responses following dam removal. In total, we collected data for 11 different fish taxa, sampled at 25 sites ranging across 56 river kilometers in a wilderness river for 4 years following dam removal. We show that eDNA can effectively be used to determine whether fish have recolonized past former dams, and in some cases determine the spatial extent of that recolonization.
Environmental DNA (eDNA) is an Effective Tool to Track Recolonizing Migratory Fish Following Large-Scale Dam Removal, field data
공공데이터포털
We collected environmental DNA (eDNA) data from the Elwha River, home to the world’s largest dam removal project, to track the spatial and temporal patterns of species responses following dam removal. In total, we collected data for 11 different fish taxa, sampled at 25 sites ranging across 56 river kilometers in a wilderness river for 4 years following dam removal. We show that eDNA can effectively be used to determine whether fish have recolonized past former dams, and in some cases determine the spatial extent of that recolonization.