Part 1: Biomimicry for coastal protection

Back in late February near the start of my PhD, my sponsors were asked if they had an interest in organizing a Biomimicry Open Innovation Session for 2017. Similar to last October’s Open Innovation Session organized by former Biomimicry Fellow Emily Kennedy (now a graduate!) and her sponsor GOJO, the idea is to pose a challenge statement unique to your industry that is open to collaboration and biomimicry design thinking to seek potential solutions. These sessions leverage the regional biomimicry community with support from Great Lakes Biomimicry.

Following many planning sessions with my three sponsors (Biohabitats, Cleveland Water Alliance, ODNR) as well as Great Lakes Biomimicry throughout the year, the Innovation Session was held at the Great Lakes Brewing Company Tasting Room on Wednesday November 1st from 1-5pm. 26 people from 8 unique institutions participated with 10+ biomimicry models identified and abstractions generated!

Innovation Session group photo

Participants working on biological model identification and principle abstraction at the Great Lakes Brewing Company Tasting Room, credit: Christine Hockman, Great Lakes Biomimicry

The challenge statement was as follows: To incorporate habitat features into existing and/or new shore protection structures to provide aquatic habitat for targeted fish species and enhance ecological functions, benefits and services in both freshwater riverine and coastal environments

Three potential focus areas were given:

  1. Structure: Alter structure to absorb or dissipate instead of reflect or refract wave energy. Wave reflection & refraction result in altered sediment transport pathways along Lake Erie’s shoreline.
  2. Habitat utilization: Nursery habitat for larval and young fish, habitat refugia that provide hiding places and protection against predators, feeding habitat for foraging fish.
  3. Materials: Soft structures utilize natural materials, like woody debris and vegetation, while hard structures are comprised of rock, cement and steel. Consider alternative, biologically compatible materials that offer functional benefits. Or, offer a solution between hard and soft structures or a structure that can be a combination of both hard and soft materials.

Throughout this week, I have prepared a three-part series (Tuesday through Friday morning) to share the content from the introductory presentations given at the start of the Innovation Session. I am presenting all this information for a few reasons. First, for those who didn’t attend to learn about what was presented and discussed. Second, for all those who follow this blog to learn more about the background behind my PhD thesis. 2018 (Year 2) is coming up for me already, which means a hopeful thesis proposal defense by the end of Year 2!

The three presentations were:

  • Characterization of the Ohio Lake Erie shoreline through the lens of coastal protection – Jim Park, ODNR Coastal Engineer (Part 1)
  • Aquatic habitat for targeted nearshore and open fish populations of Lake Erie – Scott Winkler, Ohio EPA Division of Surface Waters (Part 2)
  • Coastal restoration: Project examples of coastal protection and ecological function – Chris Streb, Biohabitats Ecological Engineer (Part 3)

Part 1: Characterization of the Ohio Lake Erie shoreline through the lens of coastal protection

What is a shore protection structure?
Jim gave many examples, which included revetments, seawalls, groins, breakwaters and beach.

Revetments are typically composed of large, rough, angular rock on a slope that dissipates wave energy on both the slope and rough surface. Revetments typically protect the foot of a cliff or a dune, or a dike or seawall against erosion by wave actions, storm surge and currents.

Revetment example

Example of revetment – provided by Jim Park, ODNR

Seawalls are vertical structures at the land/water interface designed to prevent erosion and storm surge flooding. They are made of concrete block, cast-in-place concrete or steel sheet pile. Seawalls reflect wave energy; they do not dissipate. Seawalls provide easy access to the water by boats docked along the wall. Steel sheet pile seawalls are almost exclusively used along the mouth of the Cuyahoga River in downtown Cleveland for transportation of goods by freighters and for recreational boaters to dock by restaurants along the water.

Seawall example

Example of seawall – provided by Jim Park, ODNR

Groins are shore-perpendicular structures made of stone, concrete or sheet-pile. They are effective in beach protection and had widespread past use in Ohio. If you are familiar with the Cleveland coastline, there are a few stone groins at Edgewater Beach and a few being installed at Perkins Beach currently!

Groin example

Example of groin – provided by Jim Park, ODNR

Breakwaters can be submerged, off-shore or connected to the land and are made up of large stone. They are designed to reduce wave action. Breakwaters are usually built to provide calm waters for harbors and marinas. Submerged breakwaters are specifically built to reduce beach erosion. A beach is typically formed or retained on the landward site.  They may also be referred to as artificial “reefs.”
If beaches are there, they are the most natural and effective form of shore protection.

Concrete rubble

Eastern Cuyahoga and Lake Counties – concrete rubble

The Ohio shoreline of Lake Erie is one of the most developed and structurally protected of the Great Lakes. Structural protection began in the early 1800s with the development of harbors, but any protection structure caused adjacent downdrift shoreline erosion. The affected shoreline, in turn, then requires armoring to mitigate the wave energy breaking directly on the shoreline rather than dissipating along the beach. As the Lake Erie Commission explains in their 2004 State of the Lake Report, “This ‘domino effect’ of erosion and shoreline armoring continues to this day.”

These shore protection structures have limited natural habitat value and alter coastal and hydrologic connections that in turn affect ecological processes and biological life cycles. On the mainland shore of western Lake Erie, the current coastal protection structures are not favorable to the nearshore biological community in both structure type and composition.

We know that coastal protection structures alter the primary mode of wave energy reduction; i.e. some reflect the waves back into the lake or refract the waves instead of dissipate. We also know these structures disrupt sediment (or the more technical term – littoral) transport pathways across the lake and many cause downdrift shoreline erosion. We also know they disconnect the land-water interface. How does this connection and other disruptions affect ecological processes and biological life cycles? We will touch on this question some with Scott Winkler’s presentation on nearshore fish populations tomorrow for Part 2!

Feel free to comment below or reach out to me on LinkedIn throughout this week if you have questions or ideas to contribute!

References:

Fuller, J.A., and B.E. Gerke. 2005. Distribution of shore protection structures and their erosion effectiveness and biological compatibility. Ohio Department of Natural Resources, Sandusky, Ohio.

[LEC] Lake Erie Commission. 2004a. State of Ohio, State of the Lake Report. Toledo, Ohio.

*Note- All shore protection structure photos were part of the presentation given by Jim Park on November 1st at Great Lakes Brewing Company Tasting Room. Permission was granted to share content and photos.

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