Carbon and nitrogen stable isotope data and R code for urban and less-disturbed mangrove food webs in the Gulf of Urabá, Colombia

This deposit contains the stable isotope data (δ¹³C, δ¹⁵N, δ³⁴S), the macrofaunal abundance and wet-weight data, the R script that reproduces every analysis, table and figure of the article, the outputs it generates, and the Source Data for all figures and tables. The study compares the food web of an urban mangrove that receives untreated domestic wastewater (Turbo Bay, eastern Gulf of Urabá, Colombian Caribbean) with that of a wild mangrove (Candelaria Bay, Atrato River delta, western Gulf of Urabá). Samples were collected from 2 to 5 December 2024. Seven components were sampled in both mangroves: sediment, seston, detritus, Melampus coffea, Minuca vocator, Vitta virginea and Poecilia reticulata. Primary producers and consumers found in one mangrove only were analysed descriptively. Isotope ratios were measured by the Stable Isotopes in Nature Laboratory (SINLAB), University of New Brunswick, Canada, and 97 of 100 samples were retained after quality control. Urban − wild differences were estimated for each component with 95% bootstrap confidence intervals and exact permutation tests. Differences across the seven components were tested with 9,999 Freedman–Lane permutations, and the shifts of basal pools and consumers were compared, including an equivalence test. Stable Isotope Trajectory Analysis was used to compare the direction of the shifts, and the possible sewage contribution was bounded with two-end-member scenarios.