by Peter Etnoyer
A new species of deep-sea bamboo coral, a calcareous sea fan called Isidella, was reported yesterday by Discovery News and MSNBC. The species will debut with a full and proper binomial in the Proceedings of the Biological Society of Washington at the end of December 2008. If you can’t wait, a 52 in skeleton from 3400 ft in the deep Gulf of Alaska is now on display in Smithsonian National Museum of Natural History’s Sant Ocean Hall.
This is, as they say, “my new species”. Folks do you that favor when you’ve been studying something for such a ridiculously long time. But its not really mine, of course. I’ll see the skeleton on display for the first time this January, six long years since I first saw the animal alive, in its natural habitat, through the porthole of the Alvin submersible.
Here’s the mug shot of the paratype from the forthcoming manuscript. It’s 132 cm tall, the largest bamboo coral ever collected in its entirety, retrieved by Alvin pilot Bruce Strickrott from 1032 m depth on Welker Seamount, dive 4035 in the Northeast Pacific (1). Three strategic karate chops were required to fit it in a box.
The skeleton was shipped, restored, and donated by me; and prepared for display by Ocean Hall staff. MSNBC shows a living a colony in glorious color on Giacomini Seamount. But it’s not the holotype. Not yet. For now, you only get the black and white hard-core science with a dead broken skeleton, and …hello… the world-premiere video from 700 m deep on Warwick Seamount.
We like to give you something special. Its Deep-Sea News. So here I share something really special, the actual moment of discovery. Can you feel it?
My colleagues and I discovered this creature while using Alvin to explore seamounts 700-2700 m deep in the Gulf of Alaska in 2002 and 2004. The basal tentacles were clues to the new species. You’ll only see those from a submersible or ROV. Nets and dredges will disappoint.
This was only one of a dozen remarkable discoveries. Most of the seamount peaks we surveyed were dwarven forests full of corals, sponges, crabs, and fish. Isidella was among the largest (>1 m) and most conspicuous benthic megafauna. The fact that this bamboo coral is relatively common, but new to science, tells you how little we know about the deep sea.
Bamboo corals are true “living fossils”, dating to the Early Pleistocene on outcrops in Southern Italy (2). They occur in all seas, except perhaps the Arctic, down to 4200 m (3). Bamboo corals are known to occur on the seafloor in the Mediterranean and Scandinavia since the mid 19th century, but very little is known about the habitat they create. For example, they thrive in naturally oxygen poor, or hypoxic, waters (DO ~.35 ml/L).
The octocorals are highly adapted to the deep-sea. Unlike most sea fans, the bamboo corals have a calcitic skeleton with alternating nodes of proteinaceous material, much like the human spine. The calcite provides strength. The gorgonin provides flexibility. This is important because sea fans thrive under high particle flux in strong currents, but currents can topple a colony that’s too stiff to bend in high flow.
My European colleague Dr. Hermann Ehrlich at Dresden University of Technology likes to call Isidella a “living bone” substitute because the material shows promise in biomaterial applications (4). It grows at low temperatures (2-4 C) under intense pressure, so it is denser and stronger than human bone. Calcitic bone substitutes are favorable to titanium because natural bone and muscle can recruit to the matrix.
Overall, the new species of bamboo coral is very useful scientifically. The suspension feeding colonies secrete organic and inorganic material in concentric rings, like trees. The rings are useful for age and growth studies. Isidella colonies have been estimated between 50-150 years old (5, 6) so there is potential to detect climate change in the deep-sea. Like many corals, they grow slowly, and provide important habitat for associated species of fish and invertebrates. Bamboo corals are by-catch in bottom trawl fisheries worldwide, sometimes used for jewelry.
The Gulf of Alaska Seamount Expeditions were sponsored by NOAA Office of Ocean Exploration. More than 15,000 seamounts occur worldwide. Very few have been studied in a systematic fashion. All the seamounts we surveyed are now Alaska Seamount Habitat
“You can’t fish commercially with anything that hits the bottom- no longlines, crab pots, or trawls. It’s the law,” says deep-sea dive buddy Jon Warrenchuk of Oceana. “The total marine area protected is twice the size of Yosemite National Park.”
If you’re wondering, it takes about 45 minutes for a submersible to sink 700 m to the peak of a North Pacific seamount, and two hours or more to the bottom. On a chart of Alvin sinking time, strolling to and from the lavoratory during class (= 200 m), Lost Episode (= 1000 m), football game (= 3000 m) etc..
1. Etnoyer, PJ. in press. A new species of Isidella bamboo coral (Anthozoa: Alcyonacea) from Northeast Pacific Seamount Peaks. —Proceedings of the Biological Society of Washington.
2. Di Geronimo, I., C. Messina, A. Rosso, R. Sanfilippo, F. Scutio, & A. Vertino. 2005. Enhanced biodiversity in the deep: early Pleistocene coral communities from southern Italy. — pp. 61-86 in: Cold-water Corals and Ecosystems. A. Freiwald & J. M. Roberts, eds., Springer-Verlag, Berlin, Heidelberg.
3. Bayer, FM. 1990. A new isidid octccoral (Anthozoa: Gorgonacea) from New Caledonia, with descriptions of other new species from elsewhere in the Pacific Ocean. — Proceedings of the Biological Society of Washington 103:225-228.
4. H. Ehrlich, P. Etnoyer, S. D. Litvinov, M.M. Olennikova, H. Domaschke, T. Hanke, R. Born, H. Meissner, H. Worch (2006). Biomaterial structure in deep-sea bamboo coral (Anthozoa: Gorgonacea: Isididae): perspectives for the development of bone implants and templates for tissue engineering.— Materialwissenschaft und Werkstofftechnik 37 (6): 552 – 557. doi 10.1002/mawe.200600036.
5. Roark, E. B., T. P. Guilderson, S. Flood-Page, R. B. Dunbar, B. L. Ingram, S. J. Fallon, and M. McCulloch. 2004. Radiocarbon-based ages and growth rates of bamboo corals from the Gulf of Alaska.— Geophysical Research Letters, 32.
6. Tracey, D. M., H Neil, P Marriott, AH Andrews, GM Cailliet, JA Sanchez. 2007. Age and growth rates of two genera of deep-sea bamboo corals (family Isididae) in New Zealand waters. — Bulletin of Marine Science. 81(3):393-408.