USING MACROALGAE, DISSOLVED NUTRIENT CONCENTRATIONS, AND NATURAL ABUNDANCE STABLE ISOTOPES TO TRACK SOURCES OF NITROGEN IN AQUACULTURE FARMS

Abstract

Seaweed aquaculture is a growing market in the North Atlantic which has sparked the need for finding areas that can naturally support their growth. In this thesis six farms growing Saccharina latissima, or sugar kelp, were evaluated. At these farms, kelp growth had no relationship with nitrate or phosphate, but had an inverse relationship with ammonium and temperature. This suggests that turbidity, irradiance or salinity is affecting the growth at a few sites. Not only are kelp marketable products but they are also used as tools to trace and track anthropogenic nutrients in coastal bays. In the second study, Chondrus crispus, Ulva lactuca and dissolved natural abundance isotopes of nitrate and ammonium were used to assess nutrient pollution in Shelburne, NS. This study showed that nitrogen is in a constant state of flux which makes monitoring anthropogenic source in coastal harbours difficult.