Healthy Watersheds, Healthy People, Wildlife

Posted: Wednesday, September 7, 2022
Dr. Justina Ray

Monitoring, managing cumulative effects on watershed scale is important to protect nature in order to protect human and ecosystem health

by Dr. Justina Ray, President and Senior Scientist, Wildlife Conservation Society Canada

The link between protecting natural areas and preventing pandemics received only modest attention as Canadians struggled with the impacts of coronavirus (COVID-19). This linkage is really at the heart of the issue, however, with 72 per cent of new viral disease outbreaks originating in wildlife.

Why is this happening? By pushing into intact wild areas around the world for resource extraction (logging, mining), to build roads, and to expand urban areas, we have expanded the interface between wildlife and people, raising the odds of exposure to new viruses (which are more than plentiful). As author David Quammen wrote, in The New York Times, “We disrupt ecosystems, and we shake viruses loose from their natural hosts. When that happens, they need a new host. Often, we are it.”

Could it happen here? It is happening here: the spread of Lyme disease is a perfect example of what happens when humans disrupt ecosystems, in this case by fragmenting intact forest areas and thereby allowing Lyme hosts like white-footed mice to thrive, along with black-legged ticks that spread diseases via human contact.

Climate change is also a growing factor, including by making our weather wetter and thereby creating more conducive conditions for viral carriers like mosquitoes. That is why the World Health Organization (WHO) placed “Protect and preserve the source of human health: Nature …”  as the number one priority for a “healthy recovery from COVID-19.”
A One Health approach recognizes that the health of natural areas and ecosystems is essential to human health. A great place to implement that concept is on the watershed level. Watersheds are ideal for adopting proactive conservation approaches thanks to their workable but meaningful scale and the multiple benefits that can be gained from good stewardship. These benefits include reduced flood risk, protection of water sources for safe drinking, cooling benefits of tree cover, and mental health benefits from access to green spaces.

We also need to pay much more attention to monitoring and managing cumulative effects in these watersheds: the piling of one impact on another resulting in amplification of negative effects, like combining nutrient runoffs into waterways with higher water temperatures driven by climate change or new highways that lead to more urban sprawl and more fragmented natural habitat. Careful monitoring of key indices at the watershed scale is crucial for understanding our success in managing these so-called environmental determinants of health.

– Why the pandemic story is far from over was addressed by Dr. Justina Ray, President and Senior Scientist with Wildlife Conservation Society (WCS) Canada, in a webinar to the Healthy Lake Huron – Clean Water, Clean Beaches Partnership in December of 2020. WCS has been a leading voice in pointing to the need for a One World, One Health approach to guard against future pandemics. This approach is based on its extensive scientific research on both wildlife health and effective approaches to wildlife conservation.