Understanding ecosystem health by monitoring benthic organisms: Blackbird Creek, Lake Superior

Blackbird Creek.

Photo: © Environment and Climate Change Canada.

2012-2013 Funding: $48,080, including $16,580 provided by the Great Lakes Sustainability Fund

Other Project Contributors: EcoSuperior Environmental Programs; the Ontario Ministry of Natural Resources; and the Ontario Ministry of the Environment.

In a remote creek on the north shore of Lake Superior, small organisms living in the muddy bottom sediment are providing important clues about the health of Jackfish Bay, through a program supported by the Great Lakes Sustainability Fund.

In 2011, Jackfish Bay was re-designated as an Area of Concern in Recovery. The area is located about 250 kilometres northeast of Thunder Bay. It consists of Jackfish, Moberly and Tunnel Bays, as well as a 14-kilometre stretch of Blackbird Creek and two small lakes. For many years, effluent from a pulp mill in the nearby town of Terrace Bay has been discharged directly into Blackbird Creek, contaminating the sediment and adversely affecting water quality and fish habitat.

Jackfish Bay’s Remedial Action Plan does not require the removal of contaminated sediment from Blackbird Creek. Instead, it is expected that natural processes will bury contaminants in the sediment, effectively isolating them from the water and food web. However, the recovery of the Jackfish Bay ecosystem needs to be monitored so that progressive changes in the ecosystem can be evaluated.

That’s where the mud-dwelling small organisms - known as benthos - come in. These are invertebrate organisms, such as worms, nymphs and insect larvae that dwell for all or part of their lives in the bottom sediments of lakes and rivers. Benthos respond to changes in an ecosystem faster than other members of the aquatic community. For this reason, scientists often use the health and abundance of these organisms as indicators of ecosystem health.

Project partners investigated whether the health of the benthos in Blackbird Creek changes as quickly as the water quality. Study results confirmed that benthic invertebrate monitoring provides an excellent ongoing measure of water quality in the creek - a finding that gives the partners confidence that they will be able to detect improvements in the Jackfish Bay ecosystem over time. 

The research also confirmed that the quality of effluent has a significant impact on the health of the creek ecosystem. While Blackbird Creek is still severely impaired, future improvement in the quality of effluent or reductions in the volume of effluent discharged into the creek should result in continued improvement in the ecosystem’s health. 

For more information on the Jackfish Bay Area of Concern in Recovery, please visit: InfoSuperior.

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