Alfred University collaborative effort produces possible solution to eelgrass decline
Alfred University may be hundreds of miles from fresh saltwater, but the University has become a crucible – literal and metaphoric – for an engineering effort to reinvigorate the Atlantic Ocean’s eelgrass beds, which have been disappearing at a steady rate over the past twenty years.
And it took the intervention of a professor of art history to catalyze the effort.
Alfred University Professor of Art History Mary McInnes and her husband, Drew, were spending a summer at their home on Mt. Desert Island when their 12-year-old daughter, Ellen, began participating in a day camp for young environmentalists connected with the Mount Desert Island Biological Laboratory, headed by Jane Disney.
Disney, director of the MDIBL’s Community Health Environmental Laboratory, was explaining to McInnes the challenges facing the laboratory’s efforts to transplant healthy specimens of eelgrass to coastal areas where the plant had died off.
The trick, Disney explained, was to set the plants on the sandy bottom so they could take root. The laboratory had tried attaching eelgrass to wire grids, then installing the grids during low tide in a labor intensive process. Then the U.S. Army Corps of Engineers became concerned with the environmental impact of the metal in seawater. The laboratory started experimenting with wooden frames. Light wood, such as balsa, would disintegrate in the seawater as the eelgrass plugs took root. The process of sinking the large, unwieldy wooden frames, however, was also laborious and time-consuming to the point of being impractical.
Listening to Disney describe the various issues, McInnes wondered: Why not attach the eelgrass to a ceramic material? The ceramic medium would be heavier than water, so it would sink and settle onto the sand, and the material wouldn’t pose the environmental hazard that had concerned the Corps of Engineers.
That conversation sparked a collaboration between the Mount Desert Island Biological Laboratory and Alfred University’s Inamori School of Engineering, spearheaded by Professor of Ceramic Engineering Bill Carty and joined by students studying ceramic and mechanical engineering.
Under the direction of both Carty and Assistant Professor of Mechanical Engineering Seong-Jin Lee, Alfred University students began a series of design and manufacturing processes that have resulted in a seven-holed ceramic disk, about five inches in diameter, with one convex side and an opposing, flat side. Contributing to the inter-disciplinary process was David Crenshaw, director of the digital fabrication center at Alfred University’s School of Art and Design.
According to Carty, the disks have gone through several iterations, beginning with a porcelain prototype that was actually too substantial – “A thousand years from now, someone will stub their toe on one of those,” he jokes. The project teams tried a gypsum-based material that disintegrated too quickly in sea water. The ceramic model that Carty’s team finally settled on is composed principally of terra cotta, fired at a temperature that, together with the material, ensures a steady, consistent disintegration in salt water. By the time the disk has broken into fragments, the eelgrass plants attached to it have taken root in their new ocean bed. Carty’s engineering team produced hundreds of the disks last summer for the MDIBL, and Disney – who visited Alfred University earlier this month with her MDIBL colleague Anna Ferrell – pronounces the effort so far a success.
According to marine biologists, eelgrass beds have experienced significant declines over the last two decades, possibly as a result of the commercial harvesting of mussels. Changing ocean temperatures and a growth in the green crab population have also been cited as possible causes. In any case, the deforestation of eelgrass poses a significant environmental threat. Eelgrass beds prevent ocean bed erosion and provide a habitat for a large range of marine organisms and juvenile fish such as flounder, hake and cod.
The efforts of Alfred University’s Inamori School of Engineering could help reverse that trend, not only along the eastern seaboard, but worldwide.
McInnes says she is pleased to have served as a liaison between the MDI Biological Laboratory and the Inamori School of Engineering. “My main function has been to liaison between the parties,” she says. “Alfred University has been an incubator for great interdisciplinary research.”
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