A World Beneath The Blue

One thing I’m always reminding my geography students is that while they’re used to seeing the oceans shown on world maps as wide empty blue spaces, there is really a lot of diversity beneath the surface. We look at maps of the sea-floor, and we look at pictures of benthic communities (all the critters that live on the seabed) and marine mammals (whales and seals and dolphins etc.). We talk about giant squids and undersea mountain ranges and deep mysterious valleys and trenches.

The trouble is, it’s not easy to get down there and look at that part of the world.

reef_snorkeler.jpgBut we all can get a taste of it, by trying out snorkel gear, or even better, scuba diving. The National Parks Conservation Association says you’ll find the most pristine reefs in North America at Dry Tortugas National Park, about 70 miles offshore from Key West. Besides the spectacular natural reefs, an artificial reef has been formed by a three-masted, iron-hulled sailing ship that wrecked on Loggerhead Reef in 1901. The ship attracts a wide variety of marine life and is a popular snorkeling spot. Water depths range from zero, where the wreck breaks the surface, to 20 feet at the deepest point.

drytortugas.jpgYou can also try night snorkeling in the sheltered water of the moat surrounding an old fort on the island. The underwater world changes dramatically when the sun goes down, as nocturnal creatures venture out in search of food. Bring a strong dive light and prepare to enter another world, says NPCA. Visitors come to the Dry Tortugas by boat or catch a seaplane out of Key West. Day trips and some overnight trips are available by boat. The only accommodations in the park are a small number of primitive campsites, which helps to keep visitor numbers down to a manageable level. For more information, contact the park at 305-242-7700.

I’ve always wanted to try scuba diving, too. For more info on that, check out this about.com site or this one for the Professional Association of Diving Instructors.

But even scuba divers are restricted to pretty shallow depths, because the pressure gets too great for our human little bodies. Then we need submarines, which are pretty scarce and expensive. Or we can settle for high-def real-time video delivered from remotely-operated vehicles…. which some scientists say is even better than the view they get from tiny little submersible windows anyhow.

A couple of years ago I got to sail along on a NOAA research ship as a teacher-at-sea, and was there in the science lab watching 40-inch-wide plasma screens showing the live video feed from undersea robots. It was pretty great. We saw deep-sea corals living on top of undersea mountains, lots of fish, and strange, never-before-seen landscapes of the ocean floor.

noaa-ship.jpgNOAA sends out research teams on ships around the world all the time. You can get a look at what they’re finding every day at NOAA’s Ocean Explorer site. This is an amazing Web site, and when I was on the R/V Ron Brown they had a live satellite link and sent out daily reports and updates. So it is really the next-best thing to being there. This week, a NOAA ship is mapping deep-sea coral reefs off the Hawaiian islands. You can follow along online.

Here’s what Chief Scientist John Rooney has to say about what they are up to: “Perhaps the most exciting aspect of this cruise is that we will see high-resolution imagery from parts of the seafloor that have never been photographed or observed, and there is the potential for encountering new and unexpected discoveries. … Such discoveries have the potential to literally change the way we think about the underwater world.”