The mysterious red tide toxin that has killed a record number of manatees and brought countless dead fish to Southwest Florida beaches over the past few months could finally have an explanation: The algae that produce the toxin are hungry.

A significant new study of the algae, Karenia Brevis (sic), suggests that the organisms release more toxin when they do not have enough nutrients to keep growing.

The toxin is a defense mechanism against zooplankton. Opportunistic plankton feed when the plant is not getting enough nitrogen and phosphorous - the same ingredients in many fertilizers - say researchers with North Carolina State University and the National Oceanic Atmospheric Administration.

via "Algae's hunger ramps up red tide toxins" | HeraldTribune.com (link no longer available).

Note: This article is about our research paper on algal bloom toxin defenses published in PLOS ONE last week.