Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Underwater Elephants


In the high-tech world of science, researchers sometimes need to get back to basics. UC Santa Barbara’s Douglas McCauley did just that to study the impacts of the bumphead parrotfish (Bolbometopon muricatum) on coral reef ecosystems at two remote locations in the central Pacific Ocean.

Using direct observation, animal tracking and computer simulation, McCauley, an assistant professor in the Department of Ecology, Evolution and Marine Biology, and his colleagues sought to understand whether the world’s largest parrotfish is necessary for positively shaping the structure and functioning of ecosystems. 

The answer, published in a recent issue of the journal Conservation Biology, is yes and no.“We actually swam alongside bumphead parrotfish for close to six hours at a time, taking detailed data on what they ate and where they went,” McCauley explained.“It was one of the more exhausting but wonderful experiences I’ve had as a field scientist.”Often more than 4 feet long and weighing in at more than 100 pounds, bumpheads are major coral predators; one fish can consume just over 2 tons of living coral in a year. 

They are also a threatened species in serious decline across the Pacific. Hunted throughout the region — often at night in sea caves where they sleep — they have cultural significance (i.e., they’re coveted for feasting ceremonies) among many Pacific islanders.“These large parrotfish crunch off entire pieces of reef and audibly grind them up into sand in their pharyngeal mill — specialized teeth in the back of their throat,” McCauley explained. 

“You know bumpheads are near when you begin noticing branches lopped off stony corals and golflike divot scars marking the reef.”McCauley’s research demonstrates that bumpheads exert a complex mix of positive and negative effects on reefs. On the plus side, bumpheads reduce the abundance of fast-growing algae that compete with corals for light and space. Their feeding helps corals reproduce by opening up space on reefs. 

In addition, when feeding, they can disperse small coral fragments around reefs that can later grow into adult coral colonies, just as birds disperse plant seeds.Conversely, bumpheads eat coral and this predation reduces its abundance and diversity. “They can completely consume small coral colonies, and the feeding scars they leave on large corals can be a source of physiological stress,” McCauley said. 

“The coral skeleton that they grind up and excrete falls also back atop corals as biosediment and this can amount to 50 tons of sediment a year from a school of bumpheads. Sedimentation in other contexts is known to contribute to the smothering of corals.”The team’s results highlight the diverse effects that species can have on ecosystems, adding a deeper perspective on understanding the ecological role of endangered species. McCauley noted that conservation often tacitly advances the expectation that endangered species must be good for the environment.“This viewpoint is ecologically misleading,” he added. 

“Most species do things to ecosystems that we would construe as both positive and negative. Endangered species are no different from their more abundant counterparts.” McCauley is quick to add that these findings by no means suggest that declining species like bumphead parrotfish are undeserving of protection.“We can, in fact, strengthen the integrity of the field of conservation biology by being rigidly objective about the observations we make in nature — even if this means reporting occasionally that rare species can damage ecosystems,” he added. 

“If anything, better understanding the full complement of ways that at-risk species use and affect their environment empowers us to more effectively protect them.“The case of the bumphead parrotfish is analogous in interesting ways to the African elephant,” McCauley continued. 

“African elephants are a vulnerable and imperiled species that can be agents of deforestation and reduce regional biodiversity.These effects are particularly strong in areas where elephants have been artificially confined in high-density aggregations. Science that describes how elephants reshape ecosystems can help managers more effectively approach the complicated task of reversing severe global elephant declines while protecting local ecosystems. Bumphead parrotfish are to coral reefs what elephants are to African savannas.” 
Contact Info: 

Julie Cohen
(805) 893-7220

Julie Cohen | Eurek Alert!
Further information:

Further reports about: Biology Pacific colonies coral fragments corals ecosystems elephants parrotfish species

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>