Container stable isotope content (mean ± SE) sampled across periods, (A) δ¹³C and (B) δ¹⁵N. Neighborhood designations are: CM, El Comandante; CA, Cataño; MP, Martin; Peña; PN, Puerto Nuevo; RP, Río Piedras; TO, Torrecilla; VM, Vistamar. Neighborhood shadings reflect SES levels (white and light grey = low, medium grey = moderate). Means which share a letter are not significantly different.