Scooping the Ocean Floor

Part of the Water: H2O = Life exhibition.

Just as the amount of water in the oceans seems infinite, so too does the number of fish. But today, many ocean creatures are threatened, largely due to overfishing.

One of the most harmful fishing practices is bottom trawling, in which a ship drags a huge, weighted net across the ocean floor. The wide mouth of the net scoops up all the bottom-dwelling fish in its path, while the rig, weighing several tons, scrapes the bottom, destroying cold-water coral ecosystems. Efforts are needed to restrict bottom trawling, especially in international waters.

"Scientists studying deep-sea corals are in an unfortunate race with commercial fishermen, who are trawling these corals into oblivion." -Dr. Martin Willison, Dalhousie University, Halifax, Nova Scotia

Cold-water coral
© Florian Graner/

Too Deep for Snorkeling

Most people think of coral as the reefs around tropical islands. Yet spectacular corals are also found thousands of feet below the surface, on the dark, frigid ocean floor. Cold-water coral species are different than tropical ones, but both feature beautiful branching forms and bright colors. Cold-water reefs create a protective home for a variety of other creatures, including rockfish, rabbitfish, cod, and many more.

Swept Away

When a bottom trawler drags its net across the ocean floor, the heavy framework that holds the net open breaks off many tons of living coral, which get scooped up along with the fish. Most of the remaining corals don't survive, and because some species grow as little as a millimeter per year it may take centuries for the reef to recover.

Deep Sea Discoveries

More than just beautiful hiding places for fish, cold-water coral reefs may also hold medicines of the future. Scientists have already discovered several promising anti-cancer chemicals in sponges from these reefs. Also, the hard skeletons of bamboo corals have a structure so similar to bone that they can serve as a framework for growing bone implants.

Counting coral rings

Corals form growth rings throughout their lives, much in the way that trees do. Scientists have begun decoding these coral rings, and their thousand-year records of water chemistry and temperature.