Data from: Complementarity in spatial subsidies of carbon associated with resource partitioning along multiple niche axes

Data support analyses describing the potential for niche partitioning and complementarity in a guild of suspension-feeding rocky shore invertebrates. I focused on the mussels Perna canaliculus, Mytilus galloprovincialis, Aulacomya maoriana, and Xenostrobus pulex, all of which coexist along the coastline of the South Island of New Zealand. I quantified the mussel species' distributions, both vertically on the shore and within the three-dimensional mussel bed matrix, and used carbon (delta13C) and nitrogen (delta15N) stable isotope ratios to compare species' diets. Mussels exhibited niche partitioning along all resource axes, including patterns of tide-height zonation, depth in the mussel bed, and diet. Given the mussels' use of different spatial and food resources, I evaluated the potential for complementarity with respect to mussels' roles as mediators of carbon inputs into rocky-shore ecosystems. In these systems, mussels are basal species, capturing and consuming particulate organic matter in the nearshore ocean and making it available for local consumption within the benthic community. I found that mussels accumulated appreciable amounts of carbon via growth and that even the most productive species – Perna canaliculus – only contributed about half of the mussel-mediated carbon that accumulated over a year.