Historic Sampling Effort and Nearshore Distribution of Pacific Sand Lance (Ammodytes hexapterus) In the Salish Sea, WA

Pacific sand lance (Ammodytes hexapterus) are an important component of the food web in the marine waters of the Salish Sea. These energy-dense fish constitute important prey for a variety of salmonids, groundfish, marine mammals, and seabirds. Sand lance have been well documented in nearshore surveys in Puget Sound since the early 1970's, yet little life history or biological information is available in this region outside of intertidal spawning habitat use. We conducted a retrospective analysis of nearshore sand lance distribution using historical data to elucidate basic biological parameters for sand lance of the inland marine waters of Washington state. Beach seine and tow net data were gathered from federal, state and county agencies, tribes, universities, private consulting businesses, and non-profit organizations. The majority of beach seining was intended to capture salmon smolt in the nearshore, and for studies documenting general species composition. We compiled 15,192 records collected between 1970 and 2009, from 1431 unique sites, representing 13% of Puget Sound’s shoreline. Sand lance were present in 21% of the records, and captured during every month of the year. Sites were separated into the seven watershed basins outlined by the Puget Sound Nearshore Ecosystem Restoration Project, and maps were produced depicting sand lance presence and catch size by basin. Whidbey Basin had the highest sampling effort, with sand lance comprising 68% of all sites and 49% of all records. Of stream mouths sampled along the shoreline, sand lance were present at 33%. The maximum number captured in a single net increased between May and August, with all captures exceeding 4000 sand lance per net also occurring during this period.. The three northern basins comprised 87% of these large captures, with all captures greater than 10,000 fish also from these basins.. A subset of the data found fork length ranging from 1.7 cm to 19.0 cm, with 6.5% of measured fish greater than 12 cm. This could suggest adult sand lance are smaller in Puget Sound than in the North Pacific, or that the majority of sand lance observed were not adults. There was low variability in fork length for individual samples. Extensive nearshore fish surveys throughout Puget Sound over the past 40 years demonstrate that sand lance are ubiquitous throughout the region year round, and in some instances in great abundance. Relative abundance data in our study may have application with respect to foraging patterns of sand lance predators.