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 Viruses support photosynthesis in bacteria – an evolutionary advantage?
23.02.2017 | Technische Universität Kaiserslautern

nachricht Scientists unlock ability to generate new sensory hair cells
22.02.2017 | Brigham and Women's Hospital

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Viruses support photosynthesis in bacteria – an evolutionary advantage?

23.02.2017 | Life Sciences

Researchers pave the way for ionotronic nanodevices

23.02.2017 | Power and Electrical Engineering

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>