DNA Barcoding Effective Tool for Measuring, Protecting Ecosystem Health

Better protection of biodiversity in remote and threatened natural areas from human impacts such as oil sands extraction could eventually come from a new study of large-scale DNA barcoding published today by researchers including University of Guelph biologists.

For the first time, scientists have demonstrated the usefulness of high-throughput genetic monitoring as a quick and accurate way to measure ecosystem health from environmental samples, says co-author Prof. Mehrdad Hajibabaei, Department of Integrative Biology, and a member of the U of G’s Biodiversity Institute of Ontario.

The study appears in the journal PLOS One.

The researchers used DNA sequences to distinguish groups of organisms in bulk samples from the environment. That’s important information for conservation managers monitoring human-caused impacts, he said.

“We can separate biodiversity in sites and track changes,” said Hajibabaei. “If an ecosystem goes toward degradation, we can track that change.”

The team used “high-throughput” genetic sequencing to analyze DNA from so-called indicator organisms collected in mixed samples of sediments scooped up from river beds.

Hajibabaei said existing methods for sorting and identifying indicator organisms by hand are too expensive and labour-intensive to work in large-scale resource management.

Developed by U of G biologist Paul Hebert, DNA barcoding uses a telltale snippet of genetic material to identify species of organisms more quickly, easily and cheaply.

The new study shows that biologists can use high-throughput sequencing to crunch through millions of DNA fragments from hundreds of organisms contained in bulk samples of water or soil.

The researchers analyzed sediment samples collected from the Peace-Athabasca river delta downstream from the Alberta oil sands. Using computers to analyze those samples, they were able to tell which genetic material came from which river.

Hajibabaei said the study shows that bulk DNA barcoding can work alongside other tools such as remote sensing and chemical analysis to assess ecosystem status and inform environmental assessment.

The Peace-Athabasca delta is the largest inland freshwater delta in the world and a UNESCO World Heritage Site. It’s located within Wood Buffalo National Park, the largest national park in Canada.

Referring to oil sands and hydroelectric projects in Alberta, he said, “What’s happening upstream may impact what’s happening in the delta.”

He said the method holds promise for the Canadian Aquatic Biomonitoring Network, an Environment Canada program that tracks the health of freshwater ecosystems.

The technology might also help in assessing the impacts of mining in northern Ontario, farming on Lake Winnipeg and the Red River, and forestry in Atlantic Canada.

The paper’s authors included Guelph post-doc researchers Joel Gibson, Shadi Shokralla and Ian King. They worked with researchers at Environment Canada and the University of New Brunswick.

This research was funded by Genome Canada, the Natural Sciences and Engineering Research Council and Environment Canada.