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 Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>