Figure 4.

Isotopic variability in a temperate and tropical autotrophic symbiosis (dinoflagellate–gorgonian association). The isotopic signature of temperate organisms that live in a particle‐rich environment, and in which symbionts are not very active, will mirror the isotopic signature of the organic nutrients. In contrast, the isotopic signature of tropical gorgonians that live in oligotrophic and particle‐poor environments will be influenced by the activity of the symbionts and by their uptake of dissolved inorganic nitrogen. Isotopic data for the gorgonian tissue and organic food are from Cocito et al. (2013), for the temperate system and from Ward‐Paige, Risk, and Sherwood (2005), for the tropical system. Isotopic data for the inorganic carbon are from Gillikin and Bouillon (2007) and those for inorganic nitrogen are from York, Tomasky, Valiela, and Repeta (2007)