Assessing the tolerance of the marine bryozoan Electra pilosa to decreasing salinity in a laboratory experiment

Freshwater tolerance of intertidal colonies of the marine bryozoan Electra pilosa was investigated in a laboratory setting. Decreasing activity of colonies was observed with decrease in salinity. Colonies of E. pilosa showed reduced activity of individuals in salinities of 25.5‰ - 17.1‰ after one hour, but adapted to these conditions within two hours. Irreversible damage to some colonies was observed in solutions with 14.3‰ salinity. All colonies died in solutions of 8.6‰. The results of this study suggest a high resiliency of colonies to changes in salinity. Extreme changes do, however, pose considerable challenges to the organisms and may shape future distribution of E. pilosa in a changing climate.