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Potatoes for oysters

Categorie(s): Biotechnology, Ecology, Sustainable projects

Restoring ecosystems

All over the world wet ecosytems like mangroves, marshes, coralreefs, coasts, are playing an important role in keeping the local nature in balance. This is common knowledge, but still  many of these ecosystems are disappearing or degraded. People are trying to restore these ecosystems, but usually not very successful . It is so difficult because  these ecosystems depend very much on feedback of key species. A typical chicken-and-egg-problem.

The potatoe and the oyster

Have you heard the one about the potato and the oyster? It’s not a joke, but a game-changing technology — a three-dimensional grid made from potato starch — that has the potential to help reverse the decline of the world’s oyster reefs: .Biodegradable EcoSystem Engineering Elements (BESE) is already making waves in the world of coastal conservation.

Oysters

Most of us know them only as delicacy– so delicious they have been compared to angels dancing on your tongue. But coastal conservationists see the oyster in an entirely different light.
“It’s the quiet, unsung hero of our estuaries,” says Anne Birch, (Marine Program Manager for The Nature Conservancy in Florida). In many places around the world, including Florida, oyster reefs play a vital role in keeping our coasts healthy. 
Muddy and sharp, these reefs might not be much to look at, but they improve water quality, with each oyster filtering up to 50 gallons per oyster per day. They provide nursery areas, food and shelter for countless species such as fish, crabs, shrimp and birds. They stabilize shorelines. And yes, oysters are also an economic boon, bringing upwards of $10 million into Florida alone.  “I can think of few other species that combine such great ecological and economic benefits,” says Birch.

The problem is that, as vital as they are, oyster beds are in serious decline.  Over the last two centuries, 85% of the world’s oyster habitat has disappeared. Coastal run-off, natural predators, disease and over-harvesting have taken a toll. Oyster reefs that once grew 100 feet deep in some areas have been all-but eradicated by oyster dredges. “The health of our estuaries hangs in the balance,” says Birch. “The importance of restoring oyster reefs cannot be over emphasized.”

Birch has been a part of the solution since 2005 when she began managing the Conservancy’s Indian River Lagoon Restoration project. Charged with replenishing the lagoon’s oyster reefs, she was struck by the community support she received. “Until then I had no idea how charismatic oysters are. In the seven years I worked in the lagoon,” she remembers, “we attracted over 25,000 volunteers. Adults, school children, the disabled…  people from all walks of life and abilities came out to help replenish the lagoon’s oyster beds, making and deploying oyster mats .”

And this is where BESE fits in. Oysters – and mussels – need hard surfaces on which to settle and grow. Many oyster restoration projects use plastic oyster mats or bags  filled with oyster shells, or loose fossilized shells as the substrate (foundation) for new reefs. 

When we were asked if we would be interested in adding BESE

elements as a new method,” explains Birch. “Interested? You bet we were. We had it in the water less than two months later.” 

Better than plastic

Why are Birch and other marine conservationists so excited about BESE?. Made from the byproduct in potato chip manufacturing, BESE elements have clear ecological benefits over the traditional forms of plastic substrate. It’s a three-dimensional solid grid (similar in design to an egg carton) that snaps together into sheets. It’s not labor intensive. It doesn’t leach chemicals. It’s digestible and, best of all, it biodegrades in 5 to 10 years (depending on the glue used to bind the potato starch). “It’s the ideal starter kit for an oyster reef,” she enthuses.

It could be a miracle solution,” agrees Dr. Christine Angelini, a professor of Environmental Engineering Sciences at the University of Florida, who is working with the Conservancy in Charlotte Harbor. This and three other test sites in Florida will show which variables — high or low tidal zone, temperature, salinity, prevalence of seabirds and fish, etc.– produce the best results. “The results could have a big impact on all forms of coastal conservation,” she continues. “Today so much of the work relies on plastic. How much better would it be if we could substitute it with a biodegradable material that leaves nothing but nature behind.”

New possibilities

Now this is where things get really interesting. If BESE works for oyster beds, maybe with the proper adaptions, it could take the place of plastic in all sorts of coastal and deep-water applications. If it can be tailored to suit different applications, then its potential is enormous. BESE could take the place of PVC piping in mangrove planting. It could provide a stabilizing framework for growing sea grass. It could be used as a structure for coral reef restoration. Bags made of BESE could be weighted down in intertidal areas to reinforce shorelines.



Mussels growing on BESE in the Netherlands