Closing COTS knowledge gaps

Professor Morgan Pratchett is a leading researcher on the Crown of Thorns Starfish (COTS).  In our 2014 LIRRF donor update he outlined knowledge gaps relating to COTS.  That year we received a $500,000 Commemorative Grant from The Ian Potter Foundation for research to improve ability to control coral-killing outbreaks.  The goal was to make a difference.

COTS can turn areas of reef into white lifeless skeletons. Photo credit: Morgan Pratchett

Advances in COTS science and remaining gaps are detailed in Thirty Years of Research on Crown-of-Thorns Starfish (1986–2016),  a review undertaken by Professor Pratchett and other scientists.  Five of the contributors received funding from The Ian Potter Foundation Grant.   It was published in a special September 2017 edition of Diversity, titled Biology, Ecology and Management of COTS, along with other COTS research.  See also Science Daily.

We have made a difference.  Perhaps the most important discovery so far is that household vinegar is effective in removing COTS.  See Vinegar – controlling COTS at half the cost.  Further research shows sodium bisulphate, hyper-saline solutions, lime juice and powdered citric acid are also lethal to COTS and likely to be confirmed safe for the environment, with citric acid being the most promising of these alternatives.

Lisa Bostrom-Einarsson injecting COTS with household vinegar at Lizard Island. © Lisa Bostrom-Einarsson

The following peer-reviewed papers on  COTS were added to the collection at the Lizard Island Research Station in 2017, all based wholly or in part on local research

• Age and growth of an outbreaking Acanthaster cf. solaris population within the Great Barrier Reef **

• Microsatellites Reveal Genetic Homogeneity among Outbreak Populations of Crown-of-Thorns Starfish (Acanthaster cf. solaris) on Australia’s Great Barrier Reef ** (Microsatellites are tracts of repetitive DNA.  They typically have a higher mutation rate than other areas of DNA.)

• Interactive effects of endogenous and exogenous nutrition on larval development for Crown-of-Thorns Starfish **

• The effects of salinity and pH on fertilization, early development, and hatching in the Crown-of-Thorns Seastar **

• Variation in incidence and severity of injuries among Crown-of-Thorns Starfish (Acanthaster cf. solaris) on Australia’s Great Barrier Reef. **

• Larval survivorship and settlement of Crown-of-Thorns Starfish (Acanthaster cf. solaris) at varying algal cell densities.**

• Citric Acid Injections: An Accessible and Efficient Method for Controlling Outbreaks of the Crown-of-Thorns Starfish Acanthaster cf. solaris **

• Known Predators of Crown-of-Thorns Starfish (Acanthaster spp.) and Their Role in Mitigating, If Not Preventing, Population Outbreaks **

• Environmental and biological cues for spawning in the crown-of-thorns starfish

• Interspecific variation in potential importance of planktivorous  damselfishes as predators of Acanthaster sp. eggs

**  These papers are included in the special September 2017 edition of Diversity.