2015 Summer Internship Program
Acoustic Substrate Classification of the Chukchi Sea
As a senior at a small college on the coast of Maine, I was thrilled to have the opportunity to travel to Seattle and intern with the Joint Institute for the Study of Atmosphere and Ocean at the University of Washington. I spent my summer at the UW School of Aquatic and Fisheries Science and worked with John Horne at the Fisheries Acoustic and Research Lab, as well as Kim Rand from the Alaska Fisheries Science Center.
For my research project, I used acoustic remote sensing and GIS analysis to characterize substrate in the eastern Chukchi Sea between Wainwright and Barrow, Alaska. I used Echoview, a hydroacoustics software, to process acoustic data taken across six 75 km transects in the eastern Chukchi Sea as part of the Shelf Ecology and Habitat of Fish and Zooplankton (SHELFZ) project in 2013. I used the bottom classification module in Echoview to process the 38 kHz acoustic backscatter data to quantify a measure of relative substrate roughness and hardness from echo integration of the primary (E1) and secondary (E2) bottom reflections. Bottom roughness and hardness were plotted to compare offshore and inshore sediment differences and to analyze how substrate hardness varies with depth and across the Barrow Canyon. Acoustically derived sediment data were then compared to sediment data taken from traditional mechanical sediment grabs.
I found that sediment in the eastern Chukchi Sea is relatively homogenous and that bottom hardness values decreased as a function of depth. Additionally, inshore sediment was found to be harder than offshore sediment, likely because inshore ice scouring exposes bedrock. A transition zone in the Barrow Canyon consistent with water flow was found in both the acoustic and mechanical sampling data. This study found that acoustic remote sensing is an effective way to characterize benthic sediment and this method could be used to explore potential relationships between the benthic community and sediment characteristics.
In addition to working at the Fisheries Acoustics and Research Lab, I had the opportunity to travel to San Juan Island and visit Friday Harbor Labs to collect acoustic data on a marine mammal cruise. I learned so much this summer and grew as a student by working closely with researchers, professors, and other students. This JISAO summer internship experience solidified my passion for marine research and my excitement to pursue graduate school in the future. I am so grateful to JISAO and my mentors for this incredible research opportunity!
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