In the summer of 2010, I worked jointly with the National Oceanic and Atmospheric Administration (NOAA), the Northwest National Marine Renewable Energy Center (NNMREC), and Oregon State University (OSU) at the Hatfield Marine Science Center in Newport, Oregon studying the interaction of wave energy devices and the environment. Working under Dr. Sarah Henkel and Dr. Robert Emmett, my study was titled “Interaction of Wave Energy Devices and the Environment: Biofouling Concerns on Mooring Systems.”
The Pacific coast of the United States is attractive for the development of wave energy devices. The state of Oregon is a national leader in wave energy due its wave climate and state support of development in the context of marine spatial planning. One concern among marine spatial planners in regards to wave energy devices is the effects the devices may have on the environment. Furthermore, the seasonal rough seas of the Pacific Northwest have prompted investigation into the survivability of wave energy devices.
Common among all point absorbing wave energy devices is the need to be anchored and moored to the ocean floor. Additionally, most of these devices have been proposed to be installed in predominantly soft bottom areas of the ocean. Previous research has shown that the anchoring foundations of wave energy devices have an artificial reef effect attracting higher abundance of fish and crabs compared to surrounding soft bottoms.
Three buoys were designed and deployed off the coast of Newport, Oregon to test biofouling on mooring lines in regards to size, depth, and orientation. Moorings were retrieved after various durations of deployment. After retrieval, major taxa of organisms were identified and the post-fouled strength of the ropes were tested. This involved monotonically testing the biofouled mooring lines at the College of Forestry at OSU (see video below).
From this data, stress-strain curves of the ropes as well as breaking loads were computed. Additionally, samples were collected from buoys off the coast of Florence, Oregon to investigate the effects of longer term deployment.
To see the results of this study, please take a look at the Final Poster to the left. The poster has been presented at a number of conferences, including the Society for the Advancement of Native Americans and Chicanos in the Sciences (SACNAS) 2010 Annual Conference, where it won First Place in Engineering. Also, check out a video of the monotonic testing of the strength of mooring lines to the left.