Posted on EPOCA: 24 Oct 2012 — Harnessing the strength of natural glue from shelled filter-feeders.
(ISNS) — Mussels may be tasty, but for a growing set of researchers, they are also an inspiration. Their bodies spin out a fine silky thread that helps the creatures hold tight onto rocks, ship hulls, and even whales. Researchers believe that sticky substance can offer important insights for developing new adhesives.
Emily Carrington, a marine ecologist at the University of Washington’s Friday Harbor Laboratories on San Juan Island, has worked on the biology of mussel fibers for years. She noticed that natural mussel populations had a difficult time clinging to surfaces during the warmer summer months.
“Mussel silk is a thin, collagen-like protein, which the mussels mold in their foot one strand at a time, and make many make a radial array which tethers to rocks and ropes,” said Carrington.
Carrington started to look into the effects of warming and ocean acidification on mussels. Her lab raised mussels in different water and pH conditions for six weeks and then used a special materials testing machine known as a tensometer, which is typically used to testing rebar or concrete, but in this case tested the strength of the mussels’ silk-like threads, called byssus – including the glue it uses to attach to the rocks.
In research presented last month at the Third International Symposium on the Ocean in a High CO2 World, Carrington’s lab found that in water with a pH more acidic than 7.6, the mussels’ glue was significantly weakened. They also found that higher temperatures weakened the byssus fibers, with threads about 60 percent weaker in 77 degree Fahrenheit water than in cooler 65 degree water.
Worldwide, raising mussels are a $742 million business, so understanding exactly how they come unglued is important to the aquaculture industry, said Carrington.
“Farmers would want to have farms in areas that are prone to mild warming events, because slightly warmer water makes the mussels grow faster. But put climate change on top of that, they could be pushing the animals beyond their physiological limits — and they’ll have lower yields,” said Carrington.
Katharine Gammon, Inside Science, 19 October 2012. Article.