Featured Research

from universities, journals, and other organizations

Biologists Find Diatom To Reduce Red Tide's Toxicity

Date:
August 25, 2008
Source:
Georgia Institute of Technology
Summary:
Scientists have found that a diatom can reduce the levels of the red tide's toxicity to animals and that the same diatom can reduce its toxicity to other algae as well.

Skeletonema costatum (the chain-like organism) has been found to reduce the toxicity of the red tide organism (the round cells) to both animals and other algae.
Credit: Image courtesy of Georgia Institute of Technology

It’s estimated that the red tide algae, Karenia brevis, costs approximately $20 million per bloom in economic damage off the coast of Florida alone. Scientists at the Georgia Institute of Technology have found that a diatom can reduce the levels of the red tide’s toxicity to animals and that the same diatom can reduce its toxicity to other algae as well.

If scientists can learn to use this process to reduce the toxicity of red tide, they could reduce the vast amount of economic damage done to the seafood and tourism industries.

The research appears as articles in press for the Web sites of the journals Harmful Algae and the Proceedings of the Royal Society of London B.

“We found that red tide toxins can be metabolized by other species of phytoplankton. That holds true for both the brevetoxins that damage members of the animal kingdom and the as yet unknown allelopathic toxins that kill other competing species of algae,” said Julia Kubanek, an associate professor with a joint appointment in Georgia Tech’s School of Biology and School of Chemistry and Biochemistry.

Red tide is a dramatic case of an ecosystem that’s out of control. In normal seawater, K. brevis makes up about1 percent or less of the species, but during a red tide, that share increases to more than90 percent. Filter feeders such as oysters, mussels and clams ingest the dinoflagellate and become unsafe to eat. Fish killed by the red tide wash on the shore, which can be contaminated and essentially unusable to tourists for months at a time.

Kubanek and her researchers found in previous work that the growth of the diatom Skeletonema costatum was only moderately suppressed by the brevetoxins released by the red tide. So, they figured that the diatom might have a way to deal with the toxins. According to their study, they were right.

In one experiment, detailed in the journal Harmful Algae, Kubanek’s students grew the red tide algae along with the S. costatum diatom to test her group’s hypothesis and found that the samples with both organisms had a smaller concentration of brevetoxin B than samples without the diatom. They also tested the algae with four different S. costatum diatom strains from around the world and came up with largely the same results. That suggests that evolutionary experience with the red tide algae was not necessary for the diatom to resist the toxins.

In another experiment, covered in Proceedings of the Royal Society B, they found that the red tide algae was able to reduce the growth of the S. costatum diatom, but that exposure of the red tide organism to S. costatum makes the red tide less toxic to microscopic algae. That suggests that the diatom is somehow able to reduce the potency of red tide’s toxins.

“It could be that Skeletonema is degrading Karenia’s allelopathic chemicals just like it degrades brevetoxins. Or, it could be that Skeletonema is stressing Karenia out, making it harder to produce allelopathic chemicals,” said Kubanek.

What they do know is that the brevetoxins that harm oysters and other members of the animal kingdom aren’t the whole story.

“We found that when we took seawater and added purified brevetoxins to it, the live algae didn’t suffer much, so there must be other chemicals released by the red tide that are toxic to these algae,” said Kubanek.

How that’s done, isn’t clear yet, but Kubanek and her group are currently working on finding the answer to that question.

“What we do know is that this diatom, S. costatum, is able to undermine these toxins produced by the red tide, as well as the brevetoxins that are known to kill vertebrate animals like fish and dolphins,” said Kubanek.

If scientists such as Kubanek and her team can learn more about the strategies that microscopic algae use to reduce the toxicity of red tide, they might be able to use that knowledge to help reduce the poisonous effects the tide has on the animal kingdom, not to mention the damage it does to the seafood and tourism industries.

Kubanek’s research team for these studies consisted of Tracey Myers and Emily Prince from Georgia Tech and Jerome Naar of the Center for Marine Science at the University of North Carolina at Wilmington.


Story Source:

The above story is based on materials provided by Georgia Institute of Technology. Note: Materials may be edited for content and length.


Cite This Page:

Georgia Institute of Technology. "Biologists Find Diatom To Reduce Red Tide's Toxicity." ScienceDaily. ScienceDaily, 25 August 2008. <www.sciencedaily.com/releases/2008/08/080820163241.htm>.
Georgia Institute of Technology. (2008, August 25). Biologists Find Diatom To Reduce Red Tide's Toxicity. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2008/08/080820163241.htm
Georgia Institute of Technology. "Biologists Find Diatom To Reduce Red Tide's Toxicity." ScienceDaily. www.sciencedaily.com/releases/2008/08/080820163241.htm (accessed April 18, 2014).

Share This



More Plants & Animals News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Flamingo Frenzy Ahead of Zoo Construction

Flamingo Frenzy Ahead of Zoo Construction

AP (Apr. 17, 2014) With plenty of honking, flapping, and fluttering, more than three dozen Caribbean flamingos at Zoo Miami were rounded up today as the iconic exhibit was closed for renovations. (April 17) Video provided by AP
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins