The isotopic niche of the macrobenthos in a major mangrove area of the southern Caribbean Sea

Trophic organization of the mangrove macrobenthos communities is poorly known. Using nitrogen (δ¹⁵ N) and carbon (δ¹³ C) stable isotope analysis, and Bayesian models, this paper assesses the isotopic niche size and overlap between the trophic guilds of the macrobenthos in the Atrato River Delta estuary (Colombia). A total of 10 species encompassed four trophic guilds. A compact food web supports the macrobenthos, where the isotopic niche size of the community was 3.3‰². The isotopic niche size was larger for deposit feeders (4.3‰²) than omnivores (3.3‰²), followed by herbivores (1.9‰²) and carnivores (1.3‰²). Considerable overlap of isotopic niche space was found between herbivores (crabs of the Sesarmidae family) and deposit feeders (crabs of the Ocypodidae family). Both former trophic guilds constituted the first consumers within the trophic structure of the system. There also was considerable overlap between the highest trophic levels (omnivores and carnivores). These results can potentially be useful to understanding and monitoring changes in this community.