The basket cockle (Clinocardium nuttallii) is a candidate species for aquaculture in the northeast Pacific. The aim of the current research was to assess the feasibility of C. nuttallii grow‐out, with an emphasis on growth performance and qualities affecting product marketability. In this article, we investigated the combined effects of culture mode (intertidal and off‐bottom suspended culture) and initial stocking density (1500, 3000, 10 500 and 21 000 ind m−2) on C. nuttallii survival and growth during the first year of grow‐out (May through October). In intertidal culture, cockles exhibited low survival and poor growth rates. In suspended culture, survival was consistently high (>96%) at all stocking densities tested; growth and condition parameters had the highest values at 1500 and 3000 ind m−2. The edible portion (meat yield) exceeded 40% of the whole wet weight at all stocking densities, occurrences of fouled and deformed cockles were <1% and no commensal species were observed. Depending on the minimum harvestable size and stocking density chosen, harvestable proportions constituted from 1.1% to 15.2% by October of the first grow‐out year in the suspended system. The effects of stocking density and depth on second year grow‐out performance of C. nuttallii are reported in a companion paper (Dunham et al. in this issue).

The basket cockle, Clinocardium nuttallii, is a candidate species for aquaculture in British Columbia, Canada. Previous research on broodstock conditioning, embryonic development and larval rearing of C. nuttallii demonstrated the potential for reliable hatchery production of cockle seed. In this paper, we investigated the e¡ects of culture density (50% and 150% bottom cover in a monolayer) and substratum (none and ¢ne sand) on cockle seed survival, growth, behaviour and shell morphology to improve the e⁄ciency of the nursery production phase. Low stocking density (50% cover) yielded a shell length increase from 3 to 7 mm over a 4-week period. High stocking density (150% cover) negatively impacted some of the growth and condition parameters studied, but did not have a statistically sig-ni¢cant e¡ect on seed survival. Growing seed without substratum did not signi¢cantly a¡ect seed survival or growth, but led to shell deformities (at shell length 415 mm) and lower burrowing rates when cockles were subsequently placed on sand. We recommend planting seed for grow-out at a shell length not exceeding 15 mm. Acclimating seed to the substratum before planting may increase the burrowing rates, thereby reducing the risks of seed dislocation and mortality. Additional studies are required to determine optimal substratum acclimation times and techniques.

We record the spatial and temporal distribution of 8 potential vectors of West Nile virus (WNV) on Vancouver Island in 2003 and 2004. Five species were widely distributed, but the other 3 were restricted to specific larval habitats. Adults were trapped from early April to September. The findings indicate a potential for WNV transmission if the virus arrives on the island. The results extend the published range of 5 mosquito species.