Publication Abstract

This study investigates the effects of waterborne copper exposure on germling growth in chemically defined seawater. Germlings of the macroalgae, Fucus vesiculosus were exposed to a range of copper and dissolved organic carbon (DOC as humic acid) concentrations over 14 days. Germling growth was found to be a sensitive indicator of copper exposure with a TCu and LCu EC50 value of approximately 40 and 20 µg/L respectively in the absence of added DOC. The addition of DOC into the exposure media provided germlings with protection against copper toxicity, with an increased TCu EC50 value of 117.3 µg/L at a corrected DOC (DOC from humic acid only) concentration of 2.03 µg/L. The LCu EC50 was not effected by the cDOC concentration of 1.65 mg/L or less, suggesting that the LCu concentration not the TCu concentration was responsible for inhibiting germling growth. However, at a cDOC concentration of approximately 2 mg/L an increase in the LCu EC50 suggests that the LCu concentration may play some role in the overall toxicity to the germlings. This is contrary to current understanding of aquatic copper toxicity and possible explanations for this are discussed.