Development of longline mussel farming and the influence of sleeve spacing in Prince Edward Island, Canada

This paper describes the historical development of blue mussel ( Mytilus edulis) farming in Tracadie Bay (Prince Edward Island, Canada) and relates the spacing of suspended sleeves ( S S) on longlines to seston uptake. From 1990 to 2001, mussel biomass in Tracadie Bay increased by a factor of four (from 1137 to 4743 t). By 2001, seston uptake rates were approximately three-fold water renewal rates, and harvest yields (kg sleeve − 1 ) were significantly lower than in the early 1990s. A one-year field experiment was carried out to determine whether a change in S S could restore harvest yields. We found that S S (10, 20, 40, 60, 80 cm) had no significant effect on the condition index of mussels. However, high S S positively affected shell growth and abundance for small seeds that were densely packed within sleeves. A complete husbandry shift toward high S S and high seeding densities (within sleeves) may enhance farm productivity (production per unit of effort) and curtail seston uptake at the bay scale.