J OURNAL OF M ARINE E NVIRONMENTAL E NGINEERING A Comparative Analysis of Submarine Cable Installation Methods in Northern Puget Sound, Washington SHAUN AUSTIN *1 , SANDY WYLLIE-ECHEVERRIA 2 , MARTHA J. GROOM 3 1 Interdisciplinary Arts and Sciences, University of Washington, Bothell, Bothell, WA 98011 2 School of Marine Affairs and Center for Urban Horticulture, University of Washington, Seattle, WA 98105-6715 3 Interdisciplinary Arts and Sciences, University of Washington, Bothell, Bothell, WA 98011 and Department of Biology, University of Washington, Seattle, WA 98195-1800 In this study we analyze environmental impact associated with installation of submarine power cables and telecommunication lines between the islands and mainland of the North Puget Sound region. Using information from permit applications, routing plans, and biological assessments, installation techniques were evaluated for their degree of nearshore habitat disturbance. Nearly 25% of the cable projects approved between 1990 and 2000 had a negative impact to nearshore habitat with over 70% having unknown impacts. The extent of disturbances ranged from geomorphic alterations with complete loss of seagrass ( Zostera marina L. ) cover to no apparent damage. Large hydraulic trenching devices caused the most severe nearshore damage. Directional drilling and the use of existing conduit produced the least amount of impact while the technique of laying the cable on the sea bottom resulted in unknown environmental impacts. Each installation method described in this study had unique environmental concerns with implications that need further examination. Keywords: Seagrass, Submarine Cable, Disturbance, North Puget Sound INTRODUCTION North Puget Sound, including the San Juan Islands, is located in the northwest section of Washington State. The North Puget Sound region is a fjord estuary carved by retreating glaciers approximately 10,000 to 20,000 years ago. These glaciers formed deep valleys and depressions creating an array of protected bays and inlets that host a large variety of marine vegetation. Kelp, macroalgae, and seagrasses are found on the shorelines throughout this region (WDNR, 2001). North Puget Sound’s marine environment has a continuous shoreline with an estimated 80% unaltered by human activities (Bailey et al., 1998), however this may change. ____________________ *Corresponding author’s e-mail: saustin37@sbcglobal.net and current address 3308 S Bending Oak Lane Pearland, TX 77584 J. of Marine Env. Engg., Vol. 7, pp. 173-184 © 2004 Old City Publishing, Inc. Reprints available directly from the publisher Published by license under the OCP Science imprint, Photocopying permitted by license only a member of the Old City Publishing Group.