Note
An in situ survival test of fishes using hypoxic impounded mangrove swamps indicated
that some fishes change vertical position within the water column when compared to
observations under more oxygenated conditions. These observations led us to experimentally
examine changes in vertical position and activity under hypoxic conditions in juvenile snook,
Centropomus undecimalis, which are indigenous to mangrove swamp habitats. These experimental
data support our in situ data and indicate that juvenile snook move towards the oxygenated
surface waters and decrease activity there when deeper waters are anoxic.