Mean percentages of phagocytosis in leukocytes collected in winter vs. summer in green (Chelonia mydas) turtles of the Indian River Lagoon (IRL, Florida). Animals were sampled from 2011 to 2013. There were no summer data collected from the Trident Basin (TRI, Florida), but winter rates of phagocytosis are significantly higher (P<0.001) than in animals from the IRL. Additionally, IRL turtles without visible tumors (VT–) exhibited higher rates of phagocytosis than did those with visible tumors (VT+) during summer months (P=0.023). ‡=Significantly different between groups in same season. †=Significantly different between seasons for same group.