Navigation Links
Iron stimulates blooms of toxin-producing algae in open ocean, study finds
Date:11/8/2010

SANTA CRUZ, CA--A team of marine scientists has found that toxin-producing algae once thought to be limited to coastal waters are also common in the open ocean, where the addition of iron from natural or artificial sources can stimulate rapid growth of the harmful algae. The new findings, reported this week in the Proceedings of the National Academy of Sciences, add to concerns about proposals to use iron fertilization of the oceans as a way to combat global warming.

Blooms of diatoms in the genus Pseudo-nitschia, which produce a neurotoxin called domoic acid, are a regular occurrence in coastal waters. During large blooms, the algal toxin enters the food chain, forcing the closure of some fisheries (such as shellfish and sardines) and poisoning marine mammals and birds that feed on contaminated fish. But until now, blooms of these algae in the open ocean have attracted little attention from researchers.

"Normally, Pseudo-nitschia cells are sparse in the open ocean, so they don't have much effect. But these species are incredibly responsive to iron, often becoming dominant in algal blooms that result from iron fertilization. Any iron input might cause a bloom of the cells that make the toxin," said Mary Silver, professor emerita of ocean sciences at the University of California, Santa Cruz, and lead author of the new study.

Because both natural and artificial additions of iron to ocean waters cause phytoplankton (single-celled algae) to grow vigorously, and because phytoplankton take up carbon dioxide as they grow, iron fertilization of the oceans has been suggested as way to reduce atmospheric concentrations of carbon dioxide and thereby combat global warming.

"This work definitely reveals a wrinkle in those plans," said coauthor Kenneth Coale, director of Moss Landing Marine Laboratories. "It is much easier to break an ecosystem than it is to fix one. In light of these findings, we should redouble our efforts to reduce carbon emissions, the primary culprit for ocean ecosystem damage worldwide."

In 2007, Silver accompanied Ken Bruland, professor of ocean sciences at UCSC, on a research cruise to study iron chemistry in the Gulf of Alaska. She saw Pseudo-nitschia cells often in samples collected at sea, and analysis of the samples back in the lab showed the presence of the domoic acid toxin. Those findings prompted her to team up with Coale to analyze old samples collected during iron-enrichment experiments conducted in 1995 and 2002. Coale was the principal investigator or chief scientist for these studies.

"We thought the toxin would have broken down, but it was still there," Silver said.

In addition to samples from the two iron-enrichment experiments, the researchers analyzed samples from three natural populations in the North Pacific. The results showed that oceanic waters throughout the Pacific contain Pseudo-nitschia populations associated with the domoic acid neurotoxin.

Silver noted that blooms of Pseudo-nitschia must occur naturally in the open ocean as a result of iron deposited by dust storms, volcanic eruptions, and other airborne sources. "It is a natural phenomenon and likely has been for millions of years," she said. "But those are sporadic occurrences. To do iron enrichment on a large scale could be dangerous because, if it causes blooms of Pseudo-nitschia, the toxin might get into the food chain, as it does in the coastal zone."


'/>"/>

Contact: Tim Stephens
stephens@ucsc.edu
831-459-2495
University of California - Santa Cruz
Source:Eurekalert

Related biology news :

1. Thesis stimulates methods for public participation on socio-environmental policy
2. Pomegranate extract stimulates uterine contractions
3. Coccolithophore blooms in the southwest Atlantic
4. Battling harmful algal blooms
5. New research to improve management of harmful algal blooms in Puget Sound
6. New research aims to unravel how phosphorus pollution drives toxic algal blooms in the Great Lakes
7. Critical record of Afghanistans natural heritage blooms again
8. Is iron from soil a factor in algal blooms?
9. New project to forecast toxic algal blooms on Pacific Northwest beaches
10. Nitrogen fixation and phytoplankton blooms in the southwest Indian Ocean
11. A thirst for blood sparks toxic algal blooms
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/11/2017)... No two people are believed to ... York University Tandon School of Engineering and Michigan ... partial similarities between prints are common enough that ... and other electronic devices can be more vulnerable ... in the fact that fingerprint-based authentication systems feature ...
(Date:4/5/2017)... SEATTLE , April 5, 2017  The Allen ... the Allen Cell Explorer: a one-of-a-kind portal and dynamic ... large-scale 3D imaging data, the first application of deep ... edited human stem cell lines and a growing suite ... the platform for these and future publicly available resources ...
(Date:4/4/2017)... April 4, 2017   EyeLock LLC , a ... the United States Patent and Trademark Office (USPTO) has ... the linking of an iris image with a face ... represents the company,s 45 th issued patent. ... very timely given the multi-modal biometric capabilities that have ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... 11, 2017 , ... At its national board meeting in ... Sheikh, the co-founder, CEO and chief research scientist of Minnesota-based Advanced Space Technology ... in ARCS Alumni Hall of Fame . ASTER Labs is a technology ...
(Date:10/11/2017)... -- VMS BioMarketing, a leading provider of patient support solutions, has ... (CNE) network, which will launch this week. The VMS CNEs ... professionals to enhance the patient care experience by delivering peer-to-peer ... care professionals to help women who have been diagnosed and ... ...
(Date:10/10/2017)... ... October 10, 2017 , ... San Diego-based team building ... corporate rebranding initiative announced today. The bold new look is part of a ... company moves into a significant growth period. , It will also expand its service ...
(Date:10/10/2017)... Calif. , Oct. 10, 2017 SomaGenics ... from the NIH to develop RealSeq®-SC (Single Cell), expected ... for profiling small RNAs (including microRNAs) from single cells ... Program highlights the need to accelerate development of approaches ... "New techniques for measuring levels ...
Breaking Biology Technology: