Document Type

Honors Thesis

Publication Date

Winter 2015

Abstract

Ensis directus, or the Atlantic razor clam, is an infaunal bivalve species whose geographic range extends along the Atlantic coast of North America, from Canada to South Carolina. In this study, I examined the burrowing behavior of large juvenile razor clams (shell length: 60-78 mm) in two sediment types: fine mud sediment and coarse sand sediment. I categorized the burrowing behavior into four independent phases: recovery, exploration, initiation, and tunneling and recorded the proportion and time of completion of each stage of burrowing. With each clam having been exposed to both sediment types, more razor clams burrowed in the fine mud sediment and did so more quickly than in the coarse sand sediment in all phases of burrowing behavior, with statistical significant differences in the exploration, initiation, and tunneling phases between the two sediment types. Measurements of the shear and compressive strengths of both sediment types determined that the coarse sand sediment is more resistant to sediment deformation. Lastly, I utilized pressure sensors to correlate the phases of burrowing activities with changes in the pressure within sediment porewater, noting that larger changes in porewater pressure occurred while burrowing in the fine mud sediment compared to the coarse sand sediment. This research determined that the burrowing behavior of this species is sediment-dependent and should be taken into account to facilitate the establishment of razor-clam aquaculture.

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