Visible to the naked eye, benthic macroinvertebrates (also known as “benthos) are aquatic organisms that pack a huge punch. They are small animals that have no backbone and live among stones, logs, sediments and aquatic plants on the bottom of streams, rivers and lakes. Just like a canary in the early days of coal mining, benthos alert provincial biologists if there are abnormal changes that could harm Alberta’s river systems.

“Benthic monitoring has been done for years in Alberta. It is a core activity and a well-established methodology, both nationally and a part of major international monitoring’, says Fred Wrona, Chief Scientist with the Environmental Monitoring and Science Division (EMSD) (formerly AEMERA) of Alberta Environment and Parks. “EMSD adopted the approach but tailored it specifically to the Athabasca river systems in Alberta,” he says.

Unlike fish, benthos are relatively sedentary and prefer to gather at the bottom of waterbodies in the rocks and sediment. Given they do not swim around much, they are the ideal test subject to determine if water quality is being affected by oil sands development because they’re less able to escape the effects of stressors such as pollution, nutrient depletion, or contaminants.

Petri dish of benthos collected in the oil sands region. Scientists will look at the entire sample of benthos, observing the types, diversity and abundance.

Petri dish of benthos collected in the oil sands region. Scientists will look at the entire sample of benthos, observing the types, diversity and abundance.

Benthos sampling and analysis is usually done in early September in Alberta. Over a twelve day period, a team of ten or twelve biologists and environmental scientists with aquatic backgrounds pack up their research equipment and set out the day after Labour Day.

Valerie Smith, collecting benthos samples.

Valerie Smith, collecting benthos samples.

“Half of the locations that we monitor are only accessible by helicopter,” says Dr. Bruce Kilgour, lead environmental consultant at Kilgour & Associates Ltd., who works closely with EMSD. “We put on our rubber boots and waders, then load into the chopper. We get dropped down in the middle of the bush and while the blades are still spinning, we jump out just like you’d see in an action movie.”

“Six hours later, the chopper returns and we head back to the lab. By comparing communities of benthos and studying their differences, we can pinpoint types of pollutants in the water and the potential source, should we come across an abnormal sample,” he says.

Liza Hamilton, researcher with Kilgour & Associates Ltd.

Liza Hamilton, researcher with Kilgour & Associates Ltd.

Biological monitoring programs help EMSD take an active stance at protecting the well-being of the surrounding ecosystems that could be impacted by industry. Aquatic research improves our understanding of the current state of the environment and enhances the ability to detect environmental change and manage cumulative effects of the Athabasca River and its major tributaries.

Who knew something so small could tell you so much?!