TOXICITY OF A BRINE EFFLUENT ON EARLY LIFE-STAGE AND JUVENILE STRIPED BASS (MORONE SAXATILIS)

Abstract

The striped bass of the Shubenacadie River, in Nova Scotia, Canada are an important part of the Bay of Fundy population which is considered endangered by COSEWIC. The estuary is key striped bass nursery habitat and the site of the planned controlled release of a brine effluent created via formation of natural gas storage caverns. Therefore, the toxicity of the brine was quantified on the sensitive early life stages including eggs, larvae, and juveniles. The median lethal concentration of brine on striped bass ranged between 30.9-65.7 ppt, which is above a regulatory mandated 28 ppt maximum threshold for the release of brine. Threshold-observable-effect concentrations were also more than this threshold value 30.8-59.7 ppt excluding 2 conditions. Changes in salinity tolerance were related to ontogenetic development, relating to behaviour and physiology. These data suggest the current plan to release brine poses little risk to the bass.