Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Barnacles Prefer Upwelling Currents, Enriching Food Chains in the Galapagos

03.03.2010
The barnacle, a key thread in the marine food web, was thought to be missing along rocky coasts dominated by upwelling. Now a research team headed by Brown University marine ecologist Jon Witman has found the opposite to be true: Barnacle populations thrive in vertical upwelling zones in moderately deep waters in the Galapagos Islands. The findings appear in Ecological Monographs.

There’s been a rich debate in marine ecological circles about what happens to a key food source along rocky coastlines dominated by upwelling. The literature is filled with studies suggesting that the larvae of simple prey organisms such as barnacles and mussels hitch a ride on the coast-to-offshore currents typical of upwelling and are thus mostly absent in the coastal tidal zones.

That theory is getting a major challenge. In a paper in Ecological Monographs, Brown University marine ecologist Jon Witman and colleagues report that a key thread in the food web, the barnacle — the popcorn of the sea — flourishes in zones with vertical upwelling. Working at an expansive range of underwater sites in the Galapagos Islands, Witman and his team found that at two subtidal depths, barnacle larvae had latched onto rock walls, despite the vertical currents. In fact, the swifter the vertical current, the more likely the barnacles would colonize a rocky surface, the team found.

The finding “is counter to the prevailing notion about how marine communities are influenced by upwelling," said Witman, professor of biology in the Department of Ecology and Evolutionary Biology.

Barnacle communities thrived in the vertical-current sites, the team also found. The group routinely found specimens that had grown from one field season to the next to 3 centimeters (about 1 inch) in diameter — “big enough to make soup out of,” Witman said. The researchers also documented the presence of whelks and hogfish, which feast on barnacles. This predator-prey relationship shows that vertical upwelling zones are “much more dynamic ecosystems in terms of marine organisms than previously believed,” Witman said.

Professor of Biology Witman and his team, including Brown graduate student Margarita Brandt and Franz Smith of CSIRO Marine and Atmospheric Research in Australia, chose a dozen sites of underwater cliffs, ledges and slopes along a 125-kilometer-long transect in the Galapagos. During three field seasons, the team bolted nearly 1,500 plates at depths of 6 and 15 meters to track the colonization of barnacle larvae and the growth of populations in areas with weak, intermediate and strong vertical upwelling.

The team also documented for the first time the strength of currents at the sampling locations, which included a dozen islands or outcrops located in the center of the archipelago. In areas with the most vertical upwelling, the researchers found, the current moved at a brisk 0.6 meters (2 feet) per second; the weakest vertical currents were measured at 5 centimeters (0.2 feet) per second.

Scientists who study coastal marine communities had assumed that prey species such as barnacles and mussels would be largely absent in vertical upwelling areas, since the larvae, which float freely in the water as they seek a surface to attach to, would more likely be swept away in the coast-to-offshore currents. Studies of the near-surface layer of the water in rocky tidal zones confirmed that thinking. But the field work by Witman and his group, in deeper water than previous studies, told a different tale: Few barnacles were found on the plates in the weak upwelling zones, while plates at the strong upwelling sites were teeming with the crustaceans. Flourishing barnacle communities were found at both the 6-meter and 15-meter stations, the researchers reported.

The scientists think the free-floating larvae thrive in the vertical-current zones because they are constantly being bounced against the rocky walls and eventually find a tranquil spot in micro crevices in the rock to latch on to. “It’s a contact game,” Witman said.

The team suggests the observations could hold true for other rocky tidal ecosystems. “We’re one of the few people doing underwater experimental ecology in the Galapagos,” said Brandt, who is Ecuadorean. “This project is one of the first attempts to do that.”

The National Science Foundation, the Andrew W. Mellon Foundation and the private Banks Foundation funded the research.

Richard Lewis | EurekAlert!
Further information:
http://www.Brown.edu
http://news.brown.edu/pressreleases/2010/03/upwelling

More articles from Ecology, The Environment and Conservation:

nachricht How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Excess diesel emissions bring global health & environmental impacts
16.05.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>