What is eDNA?

Environmental genomics is the use the DNA left behind by organisms in the ecosystem in which they exist or through which they transit.  Through DNA sequencing and bioinformatics, this environmental DNA (eDNA) can reveal the biological characteristics of any environment.  Environmental genomics can help resolve issues inherent to the conventional approaches of assessing and monitoring biodiversity.

To accomplish environmental stewardship and sustainability goals, oil and gas companies undertake a variety of ecological measurements aimed at characterizing the environments in which they operate and monitoring changes within such environments.  Such measurements are accomplished through direct sampling (e.g., catching fish species in nets, collecting benthic organisms with grab samplers, etc…), visual and acoustic observations (e.g., marine wildlife observers trained to identify marine mammals or marine birds; scientists trained to identify salamander calls, etc…).  These conventional approaches tend to be time consuming, expensive, and often inaccurate and/or imprecise.  For example, the identification of specimens recovered from the environment relies on expert taxonomists that are often unavailable or that require a long lead (e.g., months to years) for specimen identification; visual observation are limited in low visibility and harsh environmental conditions; some acoustic observations are applicable only to vocalizing animals.  In addition, the high expenses incurred by projects undertaking biodiversity surveys is a result of the reliance on specialized and heavy equipment, the amount of time spent on the field and waiting for results from the surveys, and the cost of hiring specialists for specimen identification or visual field observations.

Environmental genomics has the potential to be cheaper, faster and to provide more complete biodiversity data than conventional methods.  The approach does away with specimen sampling and instead relies on the collection of environmental media (water, soil, sediment, air) for the identification of the organisms that inhabit a given ecosystem.  The DNA recovered from this environmental media allows the identification organisms at all trophic levels – from bacteria at the bottom of the food chain to large mammals at the top of the food chain.  Advances in high-throughput massively parallel DNA sequencing technology now provide a platform to analyse large numbers of samples in a short period of time and at a significantly cheaper rate than a decade ago.

The environmental genomics for the characterization and monitoring of biodiversity is an emerging application of genomics being developed and implemented by academics, industry, and regulators (e.g., US. Environmental Protection Agency, Environment Canada, the Norwegian Environmental protection agency, CSIRO) around the world.  In fact, many oil and gas companies have been involved in the development and application of environmental genomics over several years.