Documenting Pacific sand lance (Ammodytes hexapterus) spawning habitat in Baynes Sound, east coast Vancouver Island, and the potential interactions with intertidal shellfish aquaculture.

摘要

Intertidal beach spawning finfish, such as the Pacific sand lance ( Ammodytes hexapterus), are vulnerable to potential impacts to upper intertidal habitats from various foreshore activities, including intertidal shellfish aquaculture. This short-lived species is an important forage fish in the Pacific Northwest that rely on ecologically functioning beaches to sustain their populations. This research documented characteristics of some of the beach spawning habitat in Baynes Sound and interactions between clam tenure operations and beach spawning activity, and evaluated potential approaches to managing these interactions. Pooled data (n = 5) indicates that A. hexapterus tend to spawn on medium (50%, 0.25--0.5mm grain size) to coarse sand (30%, 0.5--2mm) substrate with 3% finer material (silt/fine sand 0.25mm). The greatest potential for interactions between predator netting and sand lance beach spawning activity is in the lower limit of spawning range and the upper limit of net placement (tidal elevation +2.7m to +3.0m CD).