The Effects of Thallus Toughness and Nutritive Quality on Palatability of Antarctic Macroalgae

Abstract

AbstractPalatability of macroalgae can be affected by many different factors including thallus toughness, nutritional quality (carbohydrates, lipids, proteins, ash), and the presence of deterrent secondary metabolites. Palatability bioassays were performed using two different antarctic algal grazers (the antarctic rockfish Notothenia coriiceps and the sea star Odontaster validus). These data were then compared to toughness and chemical composition data. Toughness was determined using a penetrometer and a wide range of thallus toughness was observed in individuals of differing species as well as of the same species. Some of the tougher individuals required more than 30 N of force to cut through the thallus while others required less than 1 N to break through. Each algal species is also being tested for percent composition of carbohydrates, lipids, proteins, as well as ash. It is hypothesized that the algal species with greater nutritional quality and/or less thallus toughness are more likely to be acceptable foods to consumers (NSF OPP9814538, OPP9901076).