By Taylor Wright

For The Chronicle-Journal

On June 27, the highly destructive emerald ash borer (EAB) was confirmed in Thunder Bay.

This small, metallic green beetle, thought to be unintentionally introduced to North America from Eastern Asia in untreated wood packaging materials, was first discovered in Detroit, Mich., and Windsor, Ont., in 2002.

It has since devastated North American ash tree populations in Ontario, Quebec, and many neighbouring American states.

In Ontario, it has already killed more than 1 million ash trees, and continues to spread.

EAB acts quickly and is capable of killing mature, healthy ash trees in three to four years once it is established.

Thunder Bay has been preparing for the arrival of EAB.

A proposed management plan, currently being reviewed by the city, recommends treating a portion of city-owned ash tree species with an insecticide, and replacing ash trees that cannot be saved with other tree species that are not attacked by the EAB.

The estimated price-tag attached to Thunder Bay's EAB management plan is approximately $6.3 million over 10 years.

The cost of managing EAB is high, but damage to an urban forest from EAB may be just as great.

A healthy urban forest provides benefits to all urban residents.

For example, urban trees help to mitigate flooding and reduce strain on infrastructure by absorbing precipitation; purify air by removing pollutants and particulate matter from the atmosphere; boost human health and wellbeing; reduce energy costs by providing shade and wind protection for houses and commercial buildings; beautify neighbourhoods and parks, leading to increased property values; amplify the green infrastructure of the community, attracting new residents, businesses, and entrepreneurs; capture and store carbon helping to mitigate climate change; and provide food and habitat for many native species of birds, insects, and mammals that call this city home.

In short, a healthy urban forest will help to ensure that Thunder Bay remains a thriving urban centre in Northern Ontario.

Thunder Bay's urban canopy currently consists of nearly 25 per cent ash trees, all of which are at risk from EAB. Many of these are located along streets, and in parks, backyards, woodlands, and greenspace throughout the city where shade trees have the greatest value.

If the urban forest of Thunder Bay was a car, EAB has just punctured one it its tires. Rapid detection and response can repair this leak and keep the operation of the car from being severely impacted.

Losing 25 per cent of the urban forest to the EAB would diminish the function, integrity, and services provided by this resource.

Learn more about the devastating impacts of EAB on urban forests online at, and how you can help by reporting any sightings of this insect to the Invading Species hotline (1-800-563-7711), or online at

The Invasive Species Centre is a non-profit organization that connects stakeholders, knowledge and technology to prevent and reduce the spread of invasive species that harm Canada's environment, economy and society. Visit the Invasive Species Centre's family of websites at or follow us on Facebook, Twitter (@InvSp) or LinkedIn.

The Ontario Invasive Plant Council is a multi-sector, non-profit group committed to the collaboration of organizations and citizens in order to effectively respond to the threat of invasive plants in Ontario. To learn more about Ontario's invasive plants and what is being done to reduce their impact please visit

Taylor Wright is project co-ordinator, Invasive Species Centre which helped to produce this piece with the Ontario Invasive Plant Council.

Recommended for you