When the sea levels rose following the last major glaciation, most rapidly between around 18,000 and 10,000 years ago, somewhat less rapidly until about 6,000 years ago, a lot of interesting things happened.
I used to live, and do archaeology in, New England (the one in the US). It was always fun to contemplate George's Bank. George's Bank is a high place out in the ocean, not far from Boston. If you've ever been whale watching off P-town, you were probably out on George's Bank, where the baleen whales forage and frolic, and are easily found during the right season. This is also a great fishing ground.
But prior to the melting of the glaciers and the rising of the seas, George's Bank was an island, and initially, a rather large one. It is almost certainly true that at the time Clovis Period native Americans were in the area, George's bank was readily accessible by modest water craft, and very likely colonized by them. But, over time, the island would have become smaller and smaller, and eventually, inundated. Anyone who lived there would have to move. A similar story happened all along the East Coast of the US. In m view, this is one of the most under-studied and under-appreciated "events" in North American prehistory, and likely relates to numerous observations in coastal prehistoric archaeology. But, perhaps owing to the deeply seated (seemingly hard wired and primordial) belief that the sea does not change even when we know it does change, this has not been developed sufficiently as an academic topic. Someone please do so.
Anyway, that's an interesting story, and versions of this happened all over world for thousands of years at the close of the last glacial. And, starting about now (geologically speaking), some version or another of this story will be happening for the next several centuries or so, as sea levels begin once again to rise rapidly, because we are polluting the earth.
Entire island nations will disappear, and entire ecological systems will vanish. But first, the canaries have to die.
And the first canary, that we know of, is Melomys rubicola, aka the Braqmble Cay Melomys. Bramble Cay is a very tiny atoll that is part of the Great Barrier Reef, and it has been inundated by human caused sea level rise. The Brable Cay Melomys is a rodent that lived only there. Lived.
Michelle Innis, writing in the New York Times, quotes the local expert:
“The key factor responsible for the death of the Bramble Cay melomys is almost certainly high tides and surging seawater, which has traveled inland across the island,” Luke Leung, a scientist from the University of Queensland who was an author of a report on the species’ apparent disappearance, said by telephone. “The seawater has destroyed the animal’s habitat and food source.”
“This is the first documented extinction of a mammal because of climate change,” he said.
Go read Michelle's report, HERE, it is quite unsettling. Then imagine similar scenarios of permanent disappearance. Times a thousand. No, times a million. You won't be able to keep track.