Ruth Dixon Turner (1914-2000) was a Harvard professor, author, curator and diver who over the course of her career became the world's expert on shipworms. Sometimes affectionately called "Lady Wormwood" because of her work on shipworms, she published more than 100 scientific papers. Her 1966 book A survey and illustrated catalogue of the Teredinidae (Mollusca: BivaIvia) was widely acclaimed as the most important book about shipworms. She was a mentor to many upcoming marine biologists. The Ernst Mayr Library's Special Collections has hundreds of recommendation letters that she wrote for graduate students.
Dr. Turner was born into a large and not particularly wealthy family; her father was a cabinet maker and her mother a dressmaker, and she was one of eight children. She first trained and worked as a teacher, but her interest in natural history led her to study ornithology, first at Cornell and then at Harvard, where she earned her doctorate in biology from Radcliffe in 1954. She soon became intrigued with mollusks, however, and became good friends with Harvard malacologist Dr. WIlliam Clench. In 1976 she was appointed Professor of Biology at Harvard.
In 1971, Dr. Turner was the first woman to descend into the ocean depths in the submersible Alvin, owned and operated by the Woods Hole Oceanographic Institution. Although at the time oceanic research was dominated by males, she was comfortable in that society, even playing poker with her colleagues. She worked with Robert Ballard, discoverer of the Titanic in 1985, and identified shipworms as the cause of the substantial loss of wood in the wreck. She helped investigate many other shipwrecks and was an expert on deep-sea vent systems. (Photo copyright Woods Hole Oceanographic Institution)
Described as "a tiny woman with a strong jaw and equally strong opinions," Dr. Turner scuba dived well into her 70s. In the days before x-rays of airplane luggage, she was said to smuggle back specimens by concealing them beneath her underwear. (Find a personal view of her here.) Her contributions to the understanding of shipworms were vast, and she studied everything from their reproduction to their biology to how they disperse. In the process she traveled around the world. She never married, but devoted herself to the mentoring of graduate students, whom she urged to "do what sets you on fire." She continued to go on expeditions until two years before her death at age 85.
Reference: Martin, Douglas. 2000. Ruth D. Turner, 85, expert on the wood-eating mollusks. New York Times May 9, 2000, C3.
The term "boring clams" sounds like a statement of the obvious. Bivalves (mollusks with two hinged shells) in general don't seem very exciting, and clams seem particularly, well, boring. But the clams in question - members of the family Teredinidae - have been responsible for a great deal of damage to man-made wooden ships and piers - anything wooden that is immersed in seawater. They dine on any kind of wood they find in the oceans - ships, including sunken wrecks, driftwood, docks, floating logs - and they have been known for thousands of years.
The Teredinidae are also known as shipworms, but they aren't worms at all, although they look wormlike. Like any self-respecting clams, they have shells, albeit only tiny ones that sit on top of their heads like helmets with sharp edges. They use these to bore through wood. Since they are unable to digest the wood themselves, they have teamed up with bacteria that provide enzymes that make digestion possible. There are more than 175 species of shipworm and adults range in size from a few centimeters to a meter in length.
As tiny larvae, the shipworms enter wood by boring tiny holes, and then they go to work tunneling through the wood. They are very respectful of each other, however, and politely abstain from encroaching on another's burrow. Also known as "termites of the sea," historically they have been transported around the world in ships' hulls.
More than 3,000 years ago the ancient Phoenicians and Egyptians covered their boats with pitch and wax to prevent shipworm incursions. The Greeks and Romans used lead, pitch and tar for the same reason. Columbus's 4th voyage to the New World was interrupted when shipworms wreaked havoc on his fleet. The animals may also have helped sink the Spanish Armada in 1588.
In the succeeding centuries, ships were covered with a variety of materials to ward off shipworms, but many of these materials leach toxins into the water so today other methods are being tested. (Ironically, during the many years that the New York harbor was heavily polluted, shipworms were not a problem, but once the water was cleaned they returned and caused surprising devastation, including the unexpected collapse of a pier.)
For more information:
- Cobb, Kristen. 2002. Return of a castaway: The gripping story of a boring clam. Science News , August 3, 2002: 72+.
- Encyclopedia of Life. 2015. Teredinidae. http://eol.org/pages/2233/overview.
- Gruson, Lindsey. 1993. In cleaner harbor, creatures eat the waterfront. New York TImes, June 27, 1993.