Blacktip sharks are snowbirds, to use a cross-species metaphor. At least, they usually are. The males of the species swim south to southern Florida during the coldest months of the year and head back north to North Carolina in the spring to mate with females.
Sea levels are rising around the world because of melting ice as well as warming waters since water expands as its temperature goes up. Average sea levels around the world are predicted to rise by about three feet by the end of the century as a consequence of the warming climate.