Transcript for Hurricane Force - A Coastal Perspective, segment 07 of 12
The warm tropical waters that provide heat and moisture to a churning hurricane are also the lifeblood to what is perhaps the ocean's most beautiful habitat, coral reefs. Reefs, both now and in the past, have always occurred in the same geographic region as hurricanes. One of a number of impacts hurricanes can have on reefs is the clouding of near-shore waters, due both to increased wave activity and to sediment-charged runoff from heavy rains.
What we saw in Florida is that mud was stirred up from many places and deposited in areas of what you'd call high energy where there's sands, and mud doesn't really belong there because the wave would wash it away, but it got deposited because there was so much mud in the water, and then over a period of weeks or months, normal wave action keeps stirring this mud up until it finally got back in equilibrium with the environment where it was - where it should have been, and so during that period, the water would stay murky every time the wind blew more than fifteen miles an hour, the waves were stirred up again, and that's not good on the corals because it cuts out the light and generally clogs up their system.
Destructive hurricane waves can have a more immediate physical impact on reefs. This was the case in nineteen eighty-nine when Hurricane Hugo's eye wall crossed the small Puerto Rican island Culebra. Here, a reputed hurricane-proof harbor was filled with more than three hundred boats seeking refuge from the storm. Winds approaching two hundred miles per hour traveled directly up the length of the harbor, destroying all but fifteen of the helpless boats, decimating the island. Reefs surrounding Culebra were most severely impacted on the windward side of the island where Hugo first made landfall.
It looked as if someone had driven through the reef with a bunch of bulldozers. Everything was leveled so the wind blows like crazy from one direction, breaks up coral, sort of piles it all one way, and then the wind blows from the other direction and moves it all back again, and this is mostly - if you could imagine the, the riverbed of a raging river with blocks of things moving along, and everything's grinding against each other. In coral, it's just the living tissue on the outside that's, that's the living animal. The rest is just dead skeleton, and that tissue is delicate, and anything that grinds against it kills it, and so, this grinding just completely sandblasted the surface of the living coral, and there's widespread coral death.