It’s not very big, but he was catching enough for a meal in the swamp waters. It’s was not deep, and of course muddy yet there were fish (and critters).
You can barely see this catch.
Below he flipped it in the air, caught then swallowed. He made sure it was head first to avoid any sharp gills.
Anhinga and Cormorants are similar species. A Cormorant has a hooked bill and dives in deeper clear water. It can be salt water. Cold doesn’t bother them much, they are common in the northern US.
Anhinga dive for fish also. However they spear prey with a sharp beak. Swamps/marshes are their preferred territory, not salt water. They are also a tropical South American bird that has moved up to the Lowcountry. They can tolerate cold for a short period.
They do well in swamps because they are very aggressive. The only real danger to them are the Alligators.
Photographed in a smaller local swamp, Magnolia Plantation property.