Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Long-Distance Larvae Speed to New Undersea Vent Homes

13.04.2010
Working in a rare, “natural seafloor laboratory” of hydrothermal vents that had just been rocked by a volcanic eruption, scientists from the Woods Hole Oceanographic Institution (WHOI) and other institutions have discovered what they believe is an undersea superhighway carrying tiny life forms unprecedented distances to inhabit the post-eruption site.

One such “pioneer species,” Ctenopelta porifera, appears to have traveled over 300 kilometers to settle at the site on the underwater mountain range known as the East Pacific Rise. “Ctenopelta had never been observed before at the…study site, and the nearest known population is 350 km to the north,” said Lauren S. Mullineaux, a senior scientist in WHOI’s biology department.

The discovery—in collaboration with the Lamont-Doherty Earth Observatory (LDEO) and the NOAA Pacific Marine Environmental Laboratory (PMEL)--clashes with the widely accepted assumption that when local adult life is wiped out in a hydrothermal eruption, it is replaced by a pool of tiny creatures from nearby vents. In this case, however, the larvae that re-settled the post-eruption vent area are noticeably different from the species that were destroyed and appeared to have traveled great distances to do so.

“This raises the question of how they can possibly disperse so far,” says Mullineaux. The findings have implications, she says, for the wider distribution of undersea life. “If these new pioneers persist and cause a regime shift, that will expand their range and increase the regional diversity,” Mullineaux says.

A report on the research by Mullineaux and her colleagues is published in the current (April 12) issue of the Proceedings of the National Academy of Sciences.

The discovery of hydrothermal vents on the bottom of the Pacific Ocean in 1977 revolutionized ideas about where and how life could exist. The seafloor vents gushing warm, mineral-rich fluids and teeming with life raised new question that researchers have been studying ever since, including: How can so much life thrive at the sunless seafloor? What is the nature of organisms at hydrothermal vents? How do animals migrate to other vent sites?

It was this last question that motivated Mullineaux and her team as they began their study of a vent area on the East Pacific Rise “to gather observations of currents, larvae and juvenile colonists…in order to understand what physical processes might facilitate dispersal,” Mullineaux says. One of the group’s primary challenges was to determine where the organisms around the vent came from.

As the scientists set out on their mission in 2006, “we got a surprise,” said Mullineaux. “A seafloor eruption was detected at our study site…resulting in changes in topography and enormous disturbance to ecological communities.

“The eruption was, in essence, a natural experiment.”

By the time the researchers arrived at the site, they found a scene quite unlike that usually observed at a hydrothermal vent. Normally, such fissures are teeming with life, supported by the hot chemicals that spew from the vents and provide food through microbial chemosynthesis, a deep-sea version of photosynthesis.

But at this spot on the East Pacific Rise, near 9 degrees North, there was no life. The eruption had wiped it out.

“Although the vents survived, the animals did not, and virtually all of the detectable invertebrate communities were paved over,” said Mullineaux. “For us, this was an exciting event. In essence it was a natural clearance experiment that allowed us to explore how this elimination of local source populations affected the supply of larvae and re-colonization.”

What they found went against the accepted assumption that most of the organisms to re-populate the area would come from relatively nearby. But instead, the new larval inhabitants came from considerable distance.

“These results show clearly that the species arriving after the eruption are different than those before,” says Mullineaux, “with two new pioneer species, Ctenopelta porifera and Lepetodrilus tevnianus, prominent.”

To the biologist, the most important finding is that “the processes of the larval stage—as opposed to those of adult organisms--seem to control colonization,” Mullineaux says. “We found that a pioneer colonization event by Ctenopelta radically changed the community structure.”

But the question remained, how were these weak-swimming larvae propelled such vast distances to the decimated vent area? The answer may lie in a recently developed model by Mullineaux’s colleagues Dennis McGillicuddy and Jim Ledwell of WHOI, Bill Lavelle of PMEL and Andreas Thurnherr of LDEO, all part of the LADDER team--LArval Dispersal on the Deep East Pacific Rise.

Seemingly the only way the emigrating larvae could get to their new home from so far away, Mullineaux says, would be to ride ocean-bottom “jets” traveling up to 10 centimeters a second, such as those identified in the work of McGillicuddy and Thurnherr.

Theoretically, however, even these ridge-crest jets might not quite be able to transport the larvae from 350 km within the time frame of their 30-day lifespan, she said. “Either the larvae are using some other transport or they are living longer than we thought,” said Mullineaux.

She speculates that large eddies, or whirlpools of water, several hundred kilometers in diameter, may be propelling the migrating larvae even faster—delivering them to their new home while they are still alive. Or perhaps, she says, the larvae are able to somehow reduce their metabolism and extend their life.

In any case, the findings present an array of fascinating scientific scenarios, Mullineaux says, that warrant further exploration.

They also may open up new ways of looking at the impacts of human activities on the seafloor, such as seafloor mineral mining, which could alter a vent site in a similar way to an eruption. Depending on the site, such activity could conceivably foster a greater diversity of species at a vent that has just been mined, or it could cause extinction, she said. But such scenarios are still highly speculative, she emphasizes.

Mullineaux’s WHOI co-authors on the study were Diane K. Adams, currently at the National Institutes of Health, Susan W. Mills and Stace E. Beaulieu.

The project was funded by the National Science Foundation, along with supplemental support from WHOI’s Deep Ocean Exploration Institute.

The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans' role in the changing global environment.

Media Relations | Newswise Science News
Further information:
http://www.whoi.edu

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>