Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Small Alga – Great Effect

22.09.2015

In a new study, scientists from the ZMT have noted significant changes in the calcareous skeleton of the alga Halimeda as a result of a more acidic water environment. These may have an impact on the formation of tropical beaches and islands, as the calcareous structures of Halimeda are an important component of their sediments.

The acidification of the oceans is increasing inexorably. In particular, marine organisms with calcareous skeletons such as sea shells, corals or calcareous algae can suffer. In a new study, scientists from the Leibniz Center for Tropical Marine Ecology (ZMT) in Bremen have noted significant changes in the calcareous skeleton of the green alga Halimeda as a result of a more acidic water environment.


Halimeda opuntia

Photo: A. Wizemann, ZMT


Halimeda with calcareous needles

Photo: A. Wizemann, ZMT

These changes are an indication of the processes that occur at a lower pH level – that is, in more acidic water – in the skeleton of the calcareous alga. Since sandy beaches in many tropical regions largely consist of skeletal fragments of these algae, these changes may have an impact on the composition and formation of tropical beaches and islands.

In the seawater facility of the ZMT, the researchers exposed the Halimeda algae to water with a lower pH level, as may be found in many regions of the oceans 40 to 50 years from now. For the first time, the research group focused on the structure of the algal skeleton.

“While many studies on calcareous algae or corals have thus far only compared the quantity of calcareous skeleton produced at different pH values, we concentrated on the microstructure of the skeleton. For this purpose, we used our scanning electron microscope which can magnify the structures of animals and plants up to 100,000 times“, said biologist Andre Wizemann, one of the authors of the study.

As the researchers observed, the Halimeda alga forms a skeleton of fine calcareous needles, which are formed during the day at the cellular surface. At night these needles recrystallise – they partially dissolve and fuse to a dense, compact skeleton armor. Thus, the alga protects itself from predators and gains stability, so that it can survive at higher water flow, for example at the edges of coral reefs.

However, such a massive skeleton can only form if the calcium saturation in the surrounding water is high. At a lower pH level the content of calcium carbonate in the sea decreases. “In the algae from the more acidic water we mainly found just the fine needles which were formed by the algal cells. While the calcium production of the alga was not hindered, it lacked the solid support structure because the process of recrystallisation was disturbed,” said Wizemann.

The small Halimeda algae may not seem very spectacular at first glance. “In warmer coastal regions, however, the calcareous structures of the dead Halimeda algae are an important component of sediments,” Wizemann added. “On the Caribbean islands their skeletal parts can comprise up to 50% of the beach sand.” If their calcareous skeleton is weak and brittle, this can have far-reaching consequences. The fine calcareous needles dissolve more easily in water than a compact skeleton does. Therefore, not much remains of the algae after their death. This in turn could have a negative effect on the formation of tropical beaches and coral reef islands, which consist largely of calcareous sediments.

Publication
Wizemann, A., Meyer, F.W., Hofmann, L.C., Wild, C., Westphal, H. (2015). Ocean acidification alters the calcareous microstructure of the green macro-alga Halimeda opuntia. Coral Reefs 34(3), pp. 941-954. DOI: 10.1007/s00338-015-1288-9.

Dr. Susanne Eickhoff | idw - Informationsdienst Wissenschaft
Further information:
http://www.zmt-bremen.de

More articles from Ecology, The Environment and Conservation:

nachricht Waste in the water – New purification techniques for healthier aquatic ecosystems
24.07.2018 | Eberhard Karls Universität Tübingen

nachricht Plenty of habitat for bears in Europe
24.07.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

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: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

Protein interaction helps Yersinia cause disease

21.08.2018 | Life Sciences

Biosensor allows real-time oxygen monitoring for 'organs-on-a-chip'

21.08.2018 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>