Intertidal beach habitat suitability model for Pacific sand lance (Ammodytes personatus) in the Salish Sea, Canada

Abstract

Pacific sand lance (Ammodytes personatus) support marine food webs in the Salish Sea, yet our knowledge of intertidal spawning habitat for this species is limited. Increasing participation in community science surveys for intertidal sand lance spawning has resulted in the detection of eggs on >90 beaches in the Canadian Salish Sea since 2001. Using this data, we developed a MaxEnt habitat suitability model using 6 environmental variables from a suite of 9. We estimate that only 5.4% of the intertidal zone of the Canadian Salish Sea has a moderate to high likelihood of providing suitable sand lance spawning habitat. This rare habitat was best predicted by its proximity to estuaries, shoreline slope, distance to predicted subtidal sand lance burying habitat, seabed substrate and aspect. Our model could be used as the basis for a Pacific coast-wide model in areas with less available information. Identifying intertidal spawning habitat of sand lance will support conservation efforts intended to maintain forage fish species.

Reduction in overwinter body condition and size of Pacific sand lance has implications for piscivorous predators during marine heatwaves

“…diatom) production (Hobson & McQuoid 1997). The region also contains important and abundant Pacific sand lance burying and spawning habitats (Robinson et al 2021, Huard et al 2022. Furthermore, the Haro Strait region provides year-round foraging habitat for mar-ine birds of many species (Bertram et al 2023)…”

“…Unlike many forage fishes which tend to migrate between inshore spawning areas and offshore overwintering areas, Pacific sand lance are typically found in the same locations year after year because their anatomy and ecology are tied to persistent patches of habitat (Robards et al 1999). Pacific sand lance lack a swim bladder for buoyancy, instead opting to bury in low silt sandy sediments in shallow nearshore waters (Robinson et al 2021) to rest, minimize predation, and develop gonads in the late autumn, and for spawning in early winter (Huard et al 2022). In summer, these fish feed in the water column near their sandy burying habitat, returning daily to the same benthic patch (Haynes & Robinson 2011).…”