Physical Factors Affecting the Abundance and Distribution of the Pacific Sand Lance Ammodytes hexapterus in the San Juan Archipelago

Abstract

Anecdotal evidence has suggested in the past that the Pacific Sand Lance, Ammodytes hexapterus is present every other year in the San Juan Archipelago. This study found the fish to be present in the San Juans, as they were last year, but not as abundant as in previous years sampling. As in numerous past studies, the A. hexapterus was found to preferentially burrow in medium to coarse-grained sand and avoid sediments higher in fine particles. General trends in tidal current speeds and the abundance of sand lance in the sediment were observed. Higher levels of fish was found in the sand when tidal currents slowed from ebb to slack.