Scientists studying the warming waters in the region say it is part of a pattern and an ominous signal of climate change. A marine heat waveMuch of the Eastern Seaboard, from the Georgia coast to southern Maine, is in the midst of what scientists define as a marine heat wave. Due to human-caused buildup of greenhouse gases in the atmosphere, marine heat waves have increased dramatically in frequency, size and severity in recent decades. Shark tagging data show a “well-established summer presence” of the species off the Maine coast, he said via email. Gawarkiewicz identified the warmer-than-normal water temperatures south of Cape Hatteras as an area of particular concern.