Understanding how well stream ecosystems recover from disturbances is an important objective for aquatic ecosystem conservation because it provides insights into these ecosystems’ resilience and the factors that influence their recovery. A common approach to evaluate stream quality is to document macroinvertebrate taxa richness. This can help identify sites of unusual biodiversity that can serve as reference sites for comparison with other streams and provide baselines for documenting long-term changes in ecosystem integrity. Estimates of macroinvertebrate taxonomic richness are strongly influenced by number of organisms collected, distribution of sampling sites and sampling duration.
Environmental DNA (eDNA) sampling is a promising tool for environmental assessment. The eDNA approach has many advantages over the traditional surveying methods such as increased scope for assessing biodiversity, increased sampling efficiency, reduced processing time, and a higher chance of detecting species. Environmental DNA can be useful in conserving aquatic ecosystems by providing data on the presence and abundance of aquatic species, their distribution and genetic diversity and complementing traditional survey methods.
The goal of this study is to analyze the efficacy of eDNA for evaluating aquatic macroinvertebrate biodiversity relative to traditional methods. Therefore, we conducted macroinvertebrate surveys using the Multiple Habitat Sampling Protocol and Hester-Dendy samplers in 23 streams that are part of a long-term monitoring program at the Savannah River Site (SRS) in South Carolina, USA. We studied the changes of macroinvertebrate communities since the last sampling effort in 2017 and compared the traditional methods currently used for bioassessment. Additionally, we analyzed the opportunities of using eDNA for monitoring benthic macroinvertebrate assemblages. Results to date show increases in overall taxa richness and sensitive taxa over time. This research can be used to understand the trajectory of recovery of SRS streams and to make improvements to current bioassessment monitoring methodologies, making them more efficient and effective.