Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Coral Reef Fish Make Their Way Home

07.05.2007
Coral reef fish hatchlings dispersed by ocean currents are able to make their way back to their home reefs again to spawn, says a groundbreaking study published today in the journal Science.

The study, whose findings are considered a major advance for fish conservation biology, was conducted by an international team of scientists from Australia, France, and the U.S. using a novel tagging method to track two populations of fish, including the endearing orange, black, and white reef-dwelling clownfish made famous in the movie “Finding Nemo.”

Led by Dr. Geoff Jones and Dr. Glenn Almany of the Australian Research Council Centre of Excellence for Coral Reef Studies at James Cook University, the study took place on coral reefs in a marine protected area in Papua New Guinea. Scientists tested a new method to trace fish from birth to spawning and detect the percentage of fish hatched on one reef that return there to spawn. The techniques used in this study can reveal the extent to which fish populations on separate reefs are isolated breeding populations, or connected by fish movements (known as ‘connectivity’). Such information is critical to effective management of reef fish populations.

Following two fish species, the clownfish (Amphiprion percula) and the vagabond butterflyfish (Chaetodon vagabundus), the scientists found that young of both species made it back to their home reef about 60 percent of the time⎯a surprising result for fish larvae that had dispersed from a small reef habitat into a large area. The researchers tagged fish at the reef surrounding a small island, Kimbe Island, within a recently-designated Marine Protected Area in Kimbe Bay, Papua New Guinea.

“If we understand how fish larvae disperse, it will enable better design of marine protected areas, and this will help in the rebuilding of threatened fish populations,” said Almany, lead author on the Science article. Other members of the team were Michael Berumen of the University of Arkansas, Woods Hole Oceanographic Institution (WHOI) biologist Simon Thorrold, and Serge Planes of the Universite de Perpignan.

The study’s results highlight three notable achievements. This is the first time scientists have successfully used a new internal tagging method in the field, as well as in the lab. It is the first larval tagging study of a pelagic (open water-swimming) spawning fish. It is also the first comparison between two fish species with different reproductive strategies and dispersal patterns.

The tagging method the team employed was developed by Simon Thorrold at WHOI. The process involves injecting minute quantities of harmless stable barium isotopes into breeding female fish of both species. “The isotopes are passed to the offspring and incorporated into the ear bones - or otoliths - of the developing embryos,” said Thorrold, “thereby labeling the hatchlings at birth with the isotopes as permanent traceable tags.”

Two months after injecting females, the scientists returned and captured newly settled fish at the same reef to determine how many had returned to their home reef and how many had migrated from other nearby reefs. The percentage of fish whose otoliths were labeled with the rare barium isotope was identified at WHOI through a technique known as laser ablation inductively coupled plasma mass spectrometry (ICP-MS).

The two species have different reproductive styles. Butterflyfish release eggs and sperm into the water, and the larvae drift and swim freely for more than a month before finding a home reef. In contrast, clownfish spawn eggs that are attached to the reef for a week before the larvae hatch and disperse in oceanic waters for 10-14 days. The larval clownfish must then find a reef, and a suitable anemone, that will be home for the remainder of its life. Currents inevitably carry both species away from the parental reef, because larval fish cannot swim well, but this study confirms that the majority of both species appear to find their way home after completing the oceanic larval phase.

Reef fish conservation programs utilizing marine protected areas are based on assumptions about how many fish migrate in from other areas and how many return to home areas to spawn. At a time of increasing pressures on coral reef ecosystems, this study provides an important piece for planning the optimum size of coral reef protected areas and breeding populations.

“Just as importantly,” said Almany of their results, “40 percent of the juveniles came from other reefs that are at least ten kilometers (five miles) away, which indicates significant exchange between populations separated by open sea. This shows how marine protected areas can contribute to maintaining fish populations outside no-fishing zones.”

The successful test of this method in the field offers scientists and managers a powerful new way to evaluate the effectiveness of management models and practices based on direct information. Thorrold is continuing this work, using the maternal labeling technique to evaluate the degree of connectivity in other fish populations, including endangered Nassau grouper in the Caribbean.

This work was funded in part by the National Science Foundation.

Media Relations Office | EurekAlert!
Further information:
http://www.whoi.edu

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

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: 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

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>