35th Anniversary logo for Friends of Casco Bay

Rising seas: confronting change and cultivating resilience

Water Reporter By Sandy Marsters Chandlers Wharf Sea Level Rise
Flooding on Portland Pier in Portland shows the local impact of sea level rise, captured by Water Reporter Sandy Marsters. The support of our Water Reporters documenting changing conditions across the Bay is proving indispensable.

Many of us are all too familiar with the feeling that the crises of climate change are larger than life, beyond the scope of our individual actions. It can be difficult to know that we can make a difference.

As climate change poses a challenge of global proportion, the strongest solutions will require the participation of many. This truth is exemplified by our community of intrepid Water Reporters, who simply by being in the right place at the right time, are capturing critical moments of climate change’s impacts around the Bay, from recording coastal erosion and nuisance algal blooms to documenting the impacts of sea level rise.

“Science shows unequivocally that our climate is changing and our seas are rising, and nothing drives home that fact quite like a photograph of city streets underwater,” says Casco Baykeeper Ivy Frignoca. “Having our Water Reporters document the real-time impacts of sea level rise around the Bay is instrumental to highlighting the fact that change is here and we must act now.”

At our Casco Bay Matters event in March, Ivy was joined by Marine Geologist Peter Slovinsky to discuss the latest science on sea level rise and increasing storm intensity. Seas are rising, driven by melting glaciers and the expansion of warming ocean waters. In Casco Bay sea levels have risen for over 100 years, demonstrated by data collected in Portland Harbor. But, Peter pointed out that nearly 50 percent of documented sea level rise here in Casco Bay has occurred in the past 30 years, representing a rapid increase in the rate of change.

Looking ahead, the frequency of “nuisance” flooding events may increase ten to fifteen-fold with just a 1.0 foot rise in sea level – a modest projection of a 1.5 foot rise is expected by 2050. Another sobering projection suggests that a 1.6 foot rise would submerge roughly half of Maine’s coastal sand dunes and beaches. Coupled with the predictions of greater storm intensity, our communities must adapt our infrastructure and coastal environments.

Water Reporter By Karla Talanian Mere Point Boat Launch Sea Level Rise
Water Reporter Karla Talanian documents high tide at Mere Point Boat Launch.

As a member of the Maine Climate Council’s Coastal and Marine Working Group, Ivy has been working to help address these issues. Of the group’s many recommendations to mitigate the impacts of rising seas and increased storm surges along Maine’s coast, one proposal is to adopt “nature-based solutions.” Salt marshes and wetlands, for example, are extremely good at absorbing impacts from storm surge and rising seas while filtering pollutants and excess nutrients. However, if these services are to be provided, we must work to maintain the resiliency and health of our coastal ecosystems.

Across Casco Bay, pilot projects are testing the efficacy of a nature-based solution called a “living shoreline.” This technique stabilizes eroding shorelines with native materials, rather than with rock or cement walls, while maintaining the natural land-water interface. This allows for habitat migration and preservation. At Wharton Point in Brunswick, a living shoreline was constructed last summer using bags of oyster shells and logs along the edge of an eroding salt marsh.

“When I visited the site in March, I could see material building up on the bags. It’s such a hopeful sign that the project is helping the marsh rebuild,” says Ivy. “Efforts like this can add up. Adapting to climate change is a marathon, not a sprint. Years down the road we’ll look back and see that even these small efforts collectively made the difference.”

A living shoreline test site in Maquoit Bay shows promise for stabilizing eroding salt marshes while maintaining the ecosystem’s natural land-water interface.