Letting nature be nature: restoring Puget Sound’s shoreline
Stretching from Admiralty Inlet to the city of Olympia, Puget Sound has 1330 miles of shoreline. Home to 4 million people along its shores, armor covers over 25% of the region’s shoreline. In the summer of 2023, we caught up with University of Washington School of Aquatic and Fisheries Sciences (UW SAFS) researcher, Jason Toft from the Wetland Ecosystem Team, who has been working for over 10 years on monitoring the impact of shoreline restoration when armor is removed. Installed throughout the last century to minimize erosion risk in the uplands, science has actually revealed the opposite is the case waterward of the armor: armor disrupts the natural ecosystem of shorelines that support habitat for much of Puget Sound’s fish, wildlife and vegetation.
In a new paper published in Restoration Ecology, Simone Des Roches, a UW SAFS Research Scientist, led a team of researchers studying the impact of armor removal and other restoration activities on shorelines through time in Puget Sound locations. “Part of the issue with evaluating the most effective shoreline restoration strategy is that it’s very hard to pinpoint only one thing, as the actions are so interactive,” shared Simone. “In general, other restoration activities such as planting native vegetation and log placement aren’t as effective without armor removal, so that remains the most important shoreline restoration strategy to start with. Everything else follows from there.”
With armor removal gaining momentum in the last decade, almost 30 restoration sites monitored by the Wetland Ecosystem Team in collaboration with their partners are covered in the new publication. “A major impetus for the removal of shoreline armor was the Puget Sound Chinook salmon being listed as threatened under the Endangered Species Act in 1999,” Jason shared. “This led to subsequent exploration of the impacts of armor on shorelines in the region.”
Once armor is removed, planting endemic, native vegetation, such as dunegrass, is one of the most important ‘living shoreline’ strategies. “When armor is initially removed, you inevitably get some erosion as the natural processes come back into play. By planting things like dunegrass that grow and establish quickly and has a lot of fine root systems that retain sediment, this is a great way to reduce a massive amount of erosion,” Simone noted. “It also has a higher chance of success as it occurs naturally in our Puget Sound region. By planting it in restoration projects, we give this flora a head-start on invasive species such as blackberry bushes. In essence, we’re kickstarting the natural endemic function before invasive ones have a chance to establish.”
So, what is considered a successful restoration of a shoreline? “The answer isn’t so simple,” said Simone. “Along with initial erosion, the removal of armor along a shoreline can make a previously tidy shoreline look, quite frankly, messy. But this is because restoring ecosystems is a process, and natural systems are dynamic. Restoration is not a one and done activity.” In many cases, scientists might not know what a successful restoration project looks like for many years as natural processes take time to adjust to armor removal.
The added effects of climate change also have unprecedented consequences that are still being studied, and so the removal of armor might not result in a shoreline looking the same as it did pre-armor. “One of the key things we deal with in our new paper is that shoreline restoration is happening at different timescales and therefore it’s difficult to look at these projects and make definitive judgements on what success looks like,” Simone noted. “Armor removal hasn’t happened on every Puget Sound shoreline on one day. And the timescales we’re looking at – spanning 10s of years – are still undergoing transitions that may even outlive us.”
A vital part of armor removal and shoreline restoration projects is public education and participation in restoration projects. “The Shoreline Monitoring Database has been essential for combining data from multiple groups, including community scientists,” Jason said. A collaborative project developed by a team including community science groups, the Washington Department of Fish and Wildlife (WDFW) and UW, the Shoreline Monitoring Database provides publicly accessible, standardized protocols to allow for widespread shoreline monitoring and training.
“There are a lot of nuances in restoration, and I would love to emphasize, especially to the public, that natural systems are messy and variable,” Simone added. “One of the things that shoreline armor and river dams are doing is constraining natural processes so there is less variability. By removing this, we end up with a wild, messy, natural system, which looking at in comparison to a neat and tidy beach, can be quite uncomfortable for many people. But I like to say: trust the process!”
A huge amount of diversity exists in the types of shorelines found in Puget Sound, from pebbly beaches and sandy beaches, to sheer cliffs and rockpools. “This means there is no one ideal shoreline to aim for in restoration projects,” said Simone. “The many types of beaches depend on where the water is flowing from, how far it flows, what direction the beach is facing, how much sediment comes in. But all these characteristics contribute to a functioning shoreline ecosystem. Because of this, the ideal functioning shoreline looks messy, with lots of logs and vegetation, the presence of beach wrack, and different types of bugs living in the washed-up seaweed and in the sand. And all of this contributes to the presence of other species such as birds, fish, and even whales that the ecosystem is supporting.”
This brings us to an important question – how far into the water does an effective, functioning, restored shoreline stretch? The answer is quite far. “The farther down the shoreline you build armor, the more naturally sloping beach you’re removing. This is an important shallow habitat and safety zone for small fishes and other marine organisms that are significant food sources for bigger species that don’t go into shallow water, such as orcas,” Simone noted. “So, shoreline restoration doesn’t just impact the small bit of visible coastline that we can see, but instead has huge implications for the entire ecosystem that makes up Puget Sound.”
“My ultimate takeaway for people interested in shoreline restoration is to embrace the disorderly – that’s what nature is,” Simone shared. “Letting nature be nature is something we should be applying not just to our shorelines, but also to our rivers and other spaces. It means we should look to creative solutions for our living spaces to be in synergy with nature, and part of this is accepting that these spaces might not be neat, tidy, predictable, and homogenous.”