Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovery of Algae’s Toxic Hunting Habits Could Help Curb Fish Kills

25.01.2010
A microbe commonly found in the Chesapeake Bay and other waterways emits a poison not just to protect itself but to stun and immobilize the prey it plans to eat, a team of researchers from four universities has discovered. The findings about algae linked to massive fish kills could lead to new ways to slow the growth of these tiny but toxic marine creatures.

The researchers studied the behavior of the algal cell Karlodinium veneficum, known as a dinoflagellate and found in estuaries worldwide. Each year millions of dollars are spent on measures to control dinoflagellates around the globe. This particular species is known to release a substance called karlotoxin, which is extremely damaging to the gills of fish. Karlodinium veneficum has been known to form large algal blooms in the Chesapeake and elsewhere, triggering an immediate harmful impact on aquatic life, including fish kills.

“This new research opens the door to reducing bloom frequency and intensity by reducing the availability of its prey,” said Allen Place of the Institute of Marine and Environmental Technology at the University of Maryland Center for Environmental Science. “As we reduce the nutrient load feeding Karlodinium’s prey and bring back the bay's most prolific filter feeder, the Eastern oyster, we could essentially limit Karlodinium’s ability to bloom.”

Place, in whose laboratory karlotoxin was discovered and characterized, was a co-author of the new study, published this week in the online Early Edition of the Proceedings of the National Academy of Sciences. Other researchers involved in the study came from the University of Minnesota, The Johns Hopkins University and the University of Hawaii.

“This is a major environmental problem, but we didn’t know why these microbes were producing the toxins in the first place,” said Joseph Katz, the William F. Ward Sr. Professor in the Department of Mechanical Engineering at Johns Hopkins and a co-author of the paper. “Some people thought they were just using the toxins to scare away other predators and protect themselves. But with this new research, we’ve provided clear evidence that this species of K. veneficum is using the toxin to stun and capture its prey.”

Historically, scientists have found it difficult to study the behavior of these tiny animals because the single-cell creatures can quickly swim out of a microscope’s shallow field of focus. But in recent years this problem has been solved through the use of digital holographic microscopy, which can capture three-dimensional images of the troublesome microbes. The technique was pioneered by Katz.

In a study published in 2007, Katz, Place and Jian Sheng, who was Katz’s doctoral student, were part of a team that reported the use of digital holographic microscopy to view the swimming behavior of K. veneficum and Pfiesteria piscicida. At the time, it appeared that K. veneficum slowed down into a “stealth mode” in order to ambush its prey while P. piscicida sped up to capture prey.

For the new paper, in which Sheng is lead author, the researchers used the same technique to more closely study the relationship between K. veneficum and its prey, a common, single-celled algal cell called a cryptophyte. They found that K. veneficum microbes release toxins to stun and immobilize their prey prior to ingestion, probably to increase the success rate of their hunt and to promote their growth.

This significantly shifts the understanding about what permits harmful algal blooms to form and grow, the researchers said. Instead of being a self-defense mechanism, the microbes’ production of poison appears to be more closely related to growth through the ingestion of a “pre-packaged” food source, the cryptophyte cell, they concluded.

“In the paper, we have answered why these complicated [toxic] molecules are made in nature in the first place and identify a possible alternative mechanism causing massive bloom,” said Sheng, who is now a faculty member in the University of Minnesota’s Department of Aerospace Engineering and Mechanics.

Other co-authors of the PNAS paper are Edwin Malkiel, an adjunct associate research scientist in the Department of Mechanical Engineering at Johns Hopkins; and Jason E. Adolf, an assistant professor in the University of Hawaii’s Department of Marine Science.

Funding for the research was provided by the National Science Foundation and the National Oceanic and Atmospheric Administration’s Coastal Oceans Program.

The journal article maybe viewed online here:
http://www.pnas.org/content/early/2010/01/14/0912254107.full.pdf+html.
Related links:
Joseph Katz’s Web Page: http://web.jhu.edu/fluid_dynamics/index.html
Johns Hopkins Department of Mechanical Engineering: http://www.me.jhu.edu/
Jian Sheng’s Web Page: http://www.aem.umn.edu/people/faculty/bio/jsheng.shtml
Allen Place’s Web Page: http://www.umbi.umd.edu/comb/faculty-directory/place/

Phil Sneiderman | Newswise Science News
Further information:
http://www.jhu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

New 3-D model predicts best planting practices for farmers

26.06.2017 | Agricultural and Forestry Science

New research reveals impact of seismic surveys on zooplankton

26.06.2017 | Life Sciences

Correct connections are crucial

26.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>