Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tropical coral reefs lose two thirds of their zooplankton through ocean acidification

21.09.2016

Dramatic decline has serious consequences for coral reefs

Tropical coral reefs lose up to two thirds of their zooplankton through ocean acidification. This is the conclusion reached by a German-Australian research team that examined two reefs with so-called carbon dioxide seeps off the coast of Papua New Guinea. At these locations volcanic carbon dioxide escapes from the seabed, lowering the water’s acidity to a level, which scientists predict for the future of the oceans.


A tropical reef, affected by ocean acidification

Alfred-Wegener-Institut / Joy N. Smith

The researchers believe that the decline in zooplankton is due to the loss of suitable hiding places. It results from the changes in the coral reef community due to increasing acidification. Instead of densely branched branching corals, robust mounding species of hard coral grow, offering the zooplankton little shelter. In a study published on 19 September 2016 at the online portal of the journal Nature Climate Change, the researchers report that the impact on the food web of the coral reefs is far-reaching, since these micro-organisms are an important food source for fish and coral.

The volcanic carbon dioxide sources off the coast of Papua New Guinea are a unique natural laboratory. "Here, we can already observe under natural conditions how the reefs may change when the world's oceans absorb more and more carbon dioxide from the atmosphere and the acidity of their water rises due to climate change," says coral expert and study co-author Prof Claudio Richter of the Alfred Wegener Institute, the Helmholtz Centre for Polar and Marine Research.

The extent of the ocean acidification is indicated by the pH of the water. The lower this value, the more acidic the water. In tropical seas, researchers usually measure a pH of 8.0 or higher. If this value drops due to acidification, though, the species which are important for a coral reef disappear.

"Our study shows that, in the course of ocean acidification, the structure of the reef fundamentally changes," says lead author Joy Smith from the Australian Institute of Marine Science. "While many branching corals dominate under normal pH conditions offering ample hiding space for the different species of zooplankton, ocean acidification shifts the community to large, massive bouldering corals, which offer the reef-associated plankton little opportunity for hiding".

The new research results show that the reefs lose two thirds of their zooplankton in this way. "This decline has far-reaching consequences for the community of life on the reef. For one thing, many fish species feed on zooplankton. On the other hand, the corals are also dependent on the floating food. Given the ever warmer and more acidic water, corals have to channel more energy into calcification, the energy-demanding process governing the formation of their calcium carbonate skeletons. The coral satisfy this additional energy requirement as well as the need for essential nitrogen and phosphorus compounds by eating zooplankton – an option that would become narrower with increasing ocean acidification," says Claudio Richter.

For this study, the researchers carried out three expeditions to two reefs in the Milne Bay Province in the east of Papua New Guinea. In each case, there were both acidified areas with a pH value of 7.8 as well as areas with a normal pH value, enabling the researchers to compare the data from acidified and non-acidified 'controls'.
A total of 29 different groups of zooplankton were identified that were hiding in the reef during the day and ascending to eat in the water column after nightfall. "To our surprise, almost all of them were affected by the decline. There were none that completely disappeared, though," says Claudio Richter.

The research was conducted as part of the German cooperative project BIOACID. Under the umbrella of BIOACID (Biological Impacts of Ocean Acidification), ten institutes have been examining how biological marine communities respond to ocean acidification and what consequences this has for the food chain, the material and energy turnover in the sea and, finally, also for the economy and society. The project began in 2009 and entered the third, final funding phase in October 2015. BIOACID is funded by the Federal Ministry of Education and Research (BMBF). The program is coordinated by the GEOMAR Helmholtz Centre for Ocean Research Kiel. A list of member institutions, information about the scientific program and the BIOACID bodies as well as facts about ocean acidification can be found at the website http://www.bioacid.de.

Lead author Joy N. Smith was funded through the EU doctoral program MARES. She gained doctoral degrees from the universities of Bremen and Plymouth.

Notes for Editors:
The study has been published under the following title in the journal Nature Climate Change:
Joy N. Smith, Glenn De’ath, Claudio Richter, Astrid Cornils, Jason M. Hall-Spencer and Katharina E. Fabricius: Ocean acidification reduces demersal zooplankton that reside in tropical coral reefs, Nature Climate Change, DOI: 10.1038/nclimate3122

You can find printable photos at the following link: http://www.awi.de/nc/en/about-us/service/press/press-release/tropische-korallenriffe-verlieren-durch-ozeanversauerung-zwei-drittel-ihres-zooplanktons.html

Your scientific contact person at the Alfred Wegener Institute is:
• Prof Claudio Richter (Tel: +49(471)4831-1304; E-mail: Claudio.Richter(at)awi.de)

Your contact in the Communications and Media department is Sina Löschke (Tel.: +49 (0)471 4831 - 2008; e-mail: medien(at)awi.de).

The Alfred Wegener Institute conducts research in the Arctic, Antarctic and in the high and mid latitude oceans. It coordinates polar research in Germany and provides important infrastructure such as the research icebreaker Polarstern and stations in the Arctic and Antarctic for the international science community. The Alfred Wegener Institute is one of the 18 research centres belonging to the Helmholtz Association, Germany's largest scientific organisation.

Ralf Röchert | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

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

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>