The ecomechanics of adhesion in marine mussels

• Main Authors: George, Matthew N, Pedigo, Ben, Edelsward, MacKenzie, Boccamazzo, Rachel, Carrington, Emily
• Format: Text
• Language: English
• Published: Western CEDAR 2016
• Subjects: Fresh Water Studies; Life Sciences; Marine Biology; Natural Resources and Conservation; Marvel; Ocean acidification
• Online Access: https://cedar.wwu.edu/ssec/2016ssec/climate_change_ocean_acidification/20

In hydrodynamically turbulent marine environments, the settlement and survival of marine organisms depend on a strong attachment to the ocean floor. Marine mussels achieve this by anchoring themselves to rocks with stretchy, collagen-like fibers (known as byssal threads) that are tipped with a natural adhesive. Synthesized in seawater and curing within days, the glue that byssal threads use is a biomechanical marvel that has inspired the synthesis of several novel synthetic glues due to its unique ability to adhere to a variety of conventionally challenging surfaces (e.g. glass, plastics, wood, and Teflon), all while in the presence of excess water, salts, and polar organic molecules. However, despite the adhesive’s notoriety little is known about how the glue matures or "cures" in natural environments and under what seawater conditions this process is either accelerated or retarded – information that could be ecologically and economically relevant as seawater conditions change as a result of ocean acidification, the expansion of hypoxic zones, and increases in sea-surface temperatures predicted by climate models. Here we describe laboratory experiments wherein mussels made byssal attachments to mica sheets that then matured in a range of different temperature, dissolved oxygen, and seawater pH conditions for up to two weeks and were then pulled to failure using a materials testing machine. Results from these assays provide insights into which environmental factors promote strong byssal attachment and inform commercial aquaculture facilities about which seawater variables should be monitored to better identify and adapt to unfavorable growing conditions.