Integrating physiology and environmental dynamics to operationalize environmental DNA (eDNA) as a means to monitor freshwater macro‐organism abundance

Citations Over TimeTop 10% of 2021 papers

Abstract

Research has demonstrated consistent positive correlations between organism abundance and absolute environmental DNA (eDNA) concentrations. Robust correlations in laboratory experiments indicate strong functional links, suggesting the potential for eDNA to monitor organism abundance in nature. However, correlations between absolute eDNA concentrations and organism abundance in nature tend to be weaker because myriad biotic and abiotic factors influence steady-state eDNA concentrations, decoupling its direct functional link with abundance. Additional technical challenges can also weaken correlations between relative organism abundance and relative eDNA data derived from metabarcoding. Future research must account for these factors to improve the inference of organism abundance from eDNA, including integrating the effects of organism physiology on eDNA production, eDNA dynamics in lentic/lotic systems, and key environmental parameters that impact estimated steady-state concentrations. Additionally, it is critical to manage expectations surrounding the accuracy and precision that eDNA can provide - eDNA, for example, cannot provide abundance estimates comparable to intensively managed freshwater fisheries that enumerate every individual fish. Recent developments, however, are encouraging. Current methods could provide meaningful information regarding qualitative conservation thresholds and emergent research has demonstrated that eDNA concentrations in natural ecosystems can provide rough quantitative estimates of abundance, particularly when models integrate physiology and/or eDNA dynamics. Operationalizing eDNA to infer abundance will probably require more than simple correlations with organism biomass/density. Nevertheless, the future is promising - models that integrate eDNA dynamics in nature could represent an effective means to infer abundance, particularly when traditional methods are considered too "costly" or difficult to obtain.

Related Papers

• → The ecology of environmental DNA and implications for conservation genetics(2015)1,139 cited
• → History, applications, methodological issues and perspectives for the use environmental DNA (eDNA) in marine and freshwater environments(2014)105 cited
• → Detection of rare and invasive freshwater fish species using eDNA pyrosequencing: Lake Iznik ichthyofauna revised(2016)34 cited
• → Book review: Environmental DNA: For Biodiversity Research and Monitoring by Pierre Taberlet, Aurélie Bonin, Lucie Zinger and Eric Coissac(2019)10 cited
• → Application of environmental DNA metabarcoding in ecology(2015)6 cited