You are here:
Habitat surrounding patch reefs influences the diet and nutrition of the western rock lobster
MacArthur, L. D., D. L. PHILLIPS, G. A. Hyndes, C. E. Hanson, AND M. A. Vanderklift. Habitat surrounding patch reefs influences the diet and nutrition of the western rock lobster. MARINE ECOLOGY PROGRESS SERIES. Inter-Research, Luhe, Germany, 436:191-205, (2011).
In this study the influence of habitat on the diet and nutrition of a common reef-associated generalist consumer, the western rock lobster Panulirus cygnus, was tested.
In this study the influence of habitat on the diet and nutrition of a common reef-associated generalist consumer, the western rock lobster Panulirus cygnus, was tested. Stable isotopes (13C/12C and 15N/14N) and gut contents were used to assess the diet of lobsters collected from eight shallow patch-reef sites on the lower west coast of Australia in April and October 2005. A Distance-based Linear Model indicated that the predominant benthic habitat surrounding a reef (seagrass or macroalgae and sand) was an important source of variation in diet explaining 52.7 and 7.0% of variation in isotope signatures and gut contents, respectively. Landscape composition is therefore an important driver of lobster diet in shallow coastal waters. Other factors such as carapace length, sex, gut fullness and season were less important. Mobile invertebrates, sessile filter feeders, coralline algae and seagrass were consumed by lobsters from seagrass and macroalgae and sand dominated sites but sessile filter feeders (predominantly sponges and ascidians) were consumed in greater volumes at macroalgae and sand dominated sites and gastropods were more important at seagrass dominated sites. A modified mass balance mixing model (IsoSource), which factored in different C:N ratios of food sources and lobster-specific δ13C and δ15N discrimination values, was used to determine the contribution of food sources to lobster nutrition. Articulated coralline red algae were important for P. cygnus diet and nutrition, especially from macroalgae and sand dominated sites where this food source contributed at least 22% by mass to lobster muscle nutrition. This food source is likely important for muscle nutrition and shell maintenance throughout the distribution of P. cygnus. Bait potentially contributed up to ~30% of lobster muscle nutrition and therefore may also play an important nutritional role for lobsters in areas where lobster-potting occurs. This study indicates that macroalgae, rather than seagrass is the most likely autochthonous energy source driving P. cygnus production in shallow coastal waters, however seagrass plays an important role as habitat for lobster prey.