THREE THINGS TO KNOW ABOUT MANGROVE FORESTS: 1) They aren’t swamps. They grow in shallow ocean waters along tropical coasts, surviving tidal fluctuations and thriving on the edge between land and sea. 2) Mangrove trees generate the freshwater they need for survival by using a variety of mechanisms to filter the salt out of the ocean water. 3) They’re essential parts of reef systems, key to the reef life. ABOVE AND BELOW Above water,Read more
Basic information about how the reef and oceans work.
WHEN PEOPLE SEE THE WORD “CORAL,” it very likely brings to mind the great mounds of star and brain corals that stand out on the reefs. In fact, “corals” include many organisms beyond the familiar stony formations, all built on similar, tiny, coral polyps. “Coral” itself is a flexible word. It applies to the coral exoskeletons that we see as the visible shells of hard corals, to the polyp animals that live within those exoskeletonsRead more
SOME TWO BILLION YEARS AGO THE CLOSEST THING TO LIVING REEFS ON OUR PLANET were widespread masses of stromatolites, mounds of cyanobacteria and sediment held together by calcium carbonate they secreted. Before they arose to dominate the seas, the earth was a hellish place. Afterwards, it was a world on the road to the evolution of life as we know it. FOREBODING PLANET Before stromatolites, the planet was largely a worldwide ocean, with landmasses noRead more
HOW FISH SLEEP DEPENDS ON THE SPECIES. Nocturnal fishes, like cardinalfishes and those closely packed platoons of grunts and gray snappers you see just hanging around by coralheads and pier pilings during day dives, are likely resting rather than actually sleeping. Some species, like parrotfish, clearly sleep at night, although they seem like they can be awakened with minor disturbances (I base this on my own clumsiness around them on night dives). Some, like blueheadRead more
NEMATOCYSTS ARE OCEAN STINGERS’ SECRET WEAPONS. In fact, they are the stingers. The way in which nematocysts sting is a story of the sneaky, harpoon-like ordnance of Phylum Cnidaria – jellyfish, coral and gorgonian polyps, sea anemones, fire corals and hydroids. If you happen to touch a sea anemone, a sea plume or coral tentacles (which you shouldn’t do), you’re likely to not feel their sting. Actually, you’ve probably been stung, ineffectively. Those animals’ stingersRead more
HERE’S A REMARKABLE PHOTO OF A SHARK PUP HATCHING, published in the terrific science magazine bioGraphic. It’s a small spotted catshark (Scyliorhinus canicula), caught just after its emergence from its egg casing. That’s its name – small spotted catshark – but the little shark has other common names, including lesser spotted dogfish. Recreational diver are not so likely to see one. S. canicula is a bottom-dweller at depths from 30 to 300 feet/10 to 300Read more
HAPPY SHARK AWARENESS DAY! I’m not sure who decreed it so but every July 14th is Shark Awareness Day. It’s a time to appreciate our cartilaginous fellow travelers on Planet Earth with a generous supply of actual shark facts. To judge by what we see on cable television, sharks are cold-blooded psychopaths always in a brutal frenzy of hunting man and beast, ready to grab a tasty arm or foot at the first opportunity. LESSRead more