My research has focused on the effect of increasing seawater temperatures on the kelp beds in Nova Scotia. Globally, warming seawater temperatures have been linked to declines in kelp populations, through both direct and indirect mechanisms. I examined the direct effects of temperature on the growth, tissue structure, strength and chemical composition of the kelp species Saccharina latissima, Laminaria digitata and Agarum clathratum. I then asked how temperature-induced changes in kelp tissue may alter interactions between these kelp species and the invasive encrusting bryozoan Membranipora membranacea, and between the kelps and their native herbivore Lacuna vincta.
I have found that temperatures above 18 ˚C damage the structure of the kelp tissue, leading to weakening and biomass loss. The increased loss of kelp tissue at high temperatures could lead to extensive biomass loss from Nova Scotia kelp beds. The chemical composition and quality of kelp as a food source for herbivores and as a substrate for Membranipora membranacea are not effected by temperature, indicating that tissue loss caused directly by temperature increases will be added to those caused by these species.
Simonson EJ, Scheibling RE, Metaxas A (Accepted) Kelp in hot water: warming seawater temperature induces weakening and loss of kelp tissue. MEPS
Simonson EJ, Metaxas A, Scheibling RE (In revision) Kelp in hot water: Effects of warming seawater temperature on kelp quality as a food source and settlement substrate. MEPS