10,000 Extremes Under the Sea: Oddities or Marvels?
Thirty years ago, scientists discovered some of the most astonishing organisms to date. Deeply seated beneath thousands of miles of ocean, these organisms have astonished scientists and baffled many laymen. These are not average organisms; they have proved to be able to withstand some of the most extreme environments on this earth, hydrothermal vents. In spite of this, the question must still be asked. How? Dr. Susan Carney, assistant professor of biology, delves deeply into this issue.
Question
How have these organisms managed to adopt such abnormal characteristics?
Answer
One thing that I should clear up is that these animals are not living in environments that are thousands of degrees. They are only living nearby, not in the most extreme temperatures. Tubeworms, mussels, and other associated invertebrates are usually found in water no warmer than 20 degrees centigrade, so it’s not quite as extreme as it’s made to seem. It’s still pretty impressive, because at the bottom of the ocean, there is intense pressure, and toxins coming out of the vents.
Q
How did these organisms start developing in the extremes?
A
It’s still a bit of a mystery. There are theories that life on earth started at hydrothermal vents, with microbes. There is also evidence that some mussel and tubeworm species have ancestors that originated in shallow water and moved into these environments.
Q
Why did these organisms take to these extreme environments?
A
Basically the only reason that any life can exist there is because they have formed these symbioses with microbes. Tubeworms cannot eat, they have no intestinal tract, but they have a bacterial sac in their body. They get their energy and nutrition from chemical reactions.
Q
Is it an advantage to live in these areas?
A
Sure. They are able to exploit these niches that no one else can. Having the ability to have developed these symbioses in these habitats is an advantage. The predisposition before their discovery was that the ocean floor was pretty barren, but now we know that some places on the floor are pretty good for supporting life with the right characteristics.
Q
Do these organisms play a role in the global ecosystem?
A
They are so far removed, that the general conception is that we don’t see their impact, but the biomass at vents and other deep-sea habitats is considerable. Tubeworms can change the chemical environment of the sediment they are living in, so they do alter their immediate environment. We just don’t quite know enough right now to assess the larger impact of deep-sea fauna, largely because we do not actually know all of the species out there. It’s going to take a lot more work to understand their impact in a more general sense of the oceans, but there is growing evidence that deep sea biodiversity contributes greatly to nutrient cycling and is essential to the health of our oceans and planet.
- Christopher Bender '10, student reporter