Contact: Bonnie Coblentz
Wind, waves, sunshine, and boat rides on the Gulf of Mexico represent peace and relaxation for many people. But the same waves that soothe beachgoers are making changes to the shoreline—an impact Mississippi State University researchers want to know more about.
The natural action of waves is responsible for much of a coastline’s features, but what happens when boats are added to the equation? In a confined space such as a bay that hosts hundreds of pleasure boats, these vessels could create a significant amount of wave energy that laps onto the miles of Gulf Coast shoreline.
MSU researchers are confronting this challenge head-on by seeking a way to preserve coastlines while boaters continue to enjoy the freedom their watercrafts offer.
Dr. Eric Sparks, director of the MSU Coastal and Marine Extension Program, said there are a variety of funded projects underway that examine different aspects of wave action impact on shorelines. These programs are coordinated from the MSU Coastal Research and Extension Center in Biloxi.
“A better understanding of wave energy sources and impact can help with design of coastal restoration projects,” said Sparks, an associate Extension professor in the Department of Wildlife, Fisheries, and Aquaculture.
Matthew Virden, Extension associate with the Coastal and Marine Extension Program, is working on three different wave studies.
One study specifically examines the influence of boat activity on waves in a semi-enclosed area that serves as an estuary. An estuary is a partially enclosed coastal body of brackish water where fresh water from rivers or streams mingles with salt water. These areas serve as valuable breeding grounds for numerous forms of sea life.
The Back Bay of Biloxi is the specific target of this wave study.
“Wave energy is a major driver for many coastal processes that directly influence shoreline vegetation and stability,” Virden said.
He explained that coastal conservation and restoration projects often include wave climate estimations in the decision-making process, but these rely on data from windwave models that incorporate variables such as wind speed and wind direction to estimate wave climate.
“Boat wake is often not incorporated into these models and is an important contributor to wave energy in semi-enclosed bodies of water,” Virden said. “In this study, site-specific wave measurements are being used to compare wind-protected and open sites in Back Bay, Mississippi.”
In tackling this tough issue, the preliminary results indicate that waves caused by boats in the Back Bay have as much or more impact on the shoreline as naturally occurring waves.
A second study is looking at the impact of waves on shoreline vegetation. Many coastal conservation and restoration projects have the primary goal of establishing or maintaining shoreline vegetation.
“Knowing which species to plant and whether or not protection structures are needed based off site-specific wave climates will help in developing an economically and ecologically efficient restoration plan,” Virden said.
Ashleigh Robbins, an Extension associate who is also a part of the Coastal and Marine Extension Program, is working on a project that focuses on the sustainability of shoreline solutions under rising sea level scenarios.
“When wave energy estimates are derived from wave gauges rather than solely relying on wind, shoreline management models can produce more accurate recommendations,” Robbins said.
She also contributes to another project that involves collecting wave data from around the bay to integrate wave gauge data into a living shoreline suitability model for Back Bay.
Wave gauges are important tools in these projects, as researchers must know the exact size, strength, and frequency of a wave impacting an area. Virden said commercial wave gauges are effective data-collecting tools, but they can be expensive.
MSU researchers developed a creative solution to the cost challenge. In another project, Virden and group members took a do-it-yourself (DIY) approach to wave gauges with a trip to the local home improvement store.
“With partners from the University of South Alabama, we created wave gauges using housing components we bought at a local store combined with high-performance yet affordable electrical components,” Virden said.
When tested side by side with a commercial wave gauge, measurements from the DIY wave gauges were in acceptable to near-perfect agreement.
“This development allowed for access to premium wave climate estimations for a fraction of the cost of commercial counterparts,” Virden said. “Additionally, these low-cost DIY wave gauges provided many opportunities for Extension and other STEM educators to incorporate low-cost teaching tools for product design, electrical engineering, data collection, coding, and processing into their curricula.”
MSU offers the DIY wave gauge plans for free to anyone who is interested. Visit coastal.msstate.edu/waves.
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