You are here: Home / News / Harmful Algal Blooms / Breakthrough Discovery Deepens Our Understanding of Why Algae Form Blooms

Breakthrough Discovery Deepens Our Understanding of Why Algae Form Blooms

A new discovery by a National Centers for Coastal Ocean Science researcher and NOAA-funded scientists in California and Scotland provides new insight into why marine algae form blooms.

It has long been known that bloom-forming microalgae influence climate and harm ecosystems and man are closely associated with certain bacterial species, but the reasons why were unknown.  The scientists discovered that the bacteria and algae have evolved a mutually beneficial arrangement in which the bacteria promote the growth of the algae by releasing a chemical that increases the biological uptake of the critical nutrient iron, while the algae release organic molecules that support bacterial growth.

They further found that dense cell blooms at the sea surface accentuate these two beneficial effects.  The new insight will help scientists and environmental managers develop more realistic bloom formation models, which will enable better bloom prediction and mitigation strategies.

Bloom-forming microscopic plants (microalgae) support world fisheries and help regulate climate; but toxic species can also cause harm.  Robust predictive ecosystem models for the formation of beneficial and harmful blooms require a fundamental knowledge of the biological and chemical processes that promote bloom formation.


Amin, Shady A., David H. Green, Mark C. Hart, Frithjof C. Küpper, William G. Sunda, and Carl J. Carrano.  2009.  Photolysis of iron-siderophore chelates promotes bacterial-algal mutualismProceedings of the National Academy of Sciences of the United States of America 106(40): 17,071-17,076.

Related NCCOS Center(s):
Shorter web link for sharing: http://coastalscience.noaa.gov/news/?p=5927

Related News and Features

  • New Tool for Identifying Harmful Algae in AlaskaNew Tool for Identifying Harmful Algae in Alaska
    A quantitative polymerase chain reaction (qPCR) assay has been developed for the dominant HAB species that causes paralytic shellfish poisoning in Alaskan waters. This assay provides positive id...
  • Research Reveals New Insights into Algae MysteryResearch Reveals New Insights into Algae Mystery
    A study by National Centers for Coastal Ocean Science researchers posits a new theory to help explain a long-standing puzzle in plankton ecology: despite limited nutrients, why is there such a high...
  • Grazers Avoid Toxic AlgaeGrazers Avoid Toxic Algae
    Can grazers help reduce the frequency and abundance of harmful algal blooms? We are considerably closer to the answer to this "top down control" question because of some recent work comparing grazi...
  • Gambierdiscus caribaeusCheaper Ciguatoxin Assay May Rely on Proxy Molecule
    A recently published finding may contribute to the development of a long-elusive affordable ciguatoxin detector, crucial for equatorial peoples worldwide at risk of contracting a severe type of s...
  • Ciguatera Assays Aim to Improve the Safety of Tropical SeafoodCiguatera Assays Aim to Improve the Safety of Tropical Seafood
    Researchers from the National Centers for Coastal Ocean Science developed effective, inexpensive molecular lab tests for field samples to detect algae responsible for a widespread seafood-borne ill...