A new study found that the Crown of Thorns Starfish (CoTS), which unprecedentedly feed on corals in the Great Barrier Reef, may be dealt with using a common kitchen staple, vinegar.
Species of CoTS or Acanthaster planci have been causing massive outbreaks of coral destruction causing serious hazards to the entire marine ecosystem. The journey to combat this problem has proven to be challenging for scientists because even though an effective intervention is available, it is expensive, hard to find and uses harmful chemicals.
Researchers from James Cook University have reached a breakthrough in solving this problem by injecting vinegar to two separate groups of CoTS from Kimbe Bay, Papua New Guinea and Lizard Island in Great Barrier Reef, Australia.
The 58 specimens from Papua New Guinea were administered with a total of either 15 or 1.5 ml vinegar via a 29-gauge hypodermic needle in two or four injection sites. On the other hand, the 99 CoTS from Great Barrier Reef were injected with a total of 25, 20, 15 or 1.5 ml vinegar in one, two or four sites, using a 19-gauge stainless steel needle.
The authors then formulated an effectivity measure by taking into account the period with which the CoTS ceased to move, the time it took for it to die and the proportion of mortality rates.
To investigate whether the gauge of the needle has an effect on the results, the researchers also injected eight more CoTS with 25 ml of vinegar using a 4-mm needle tip.
The findings of the study, published in the Coral Reefs by the Journal of the International Society for Reef Studies, showed that 100 percent of the starfish in both groups succumbed to death after 48 hours.
To test whether this method may pose a threat to other marine life species, the researchers fed the dead CoTS to the fish in laboratory trials and did not result in any ill effects. Nonetheless, the researchers said that this part of the study should further be investigated by large-scale researches. "There's no reason to think it won't work or it'll be dangerous, but we have to be sure," said Lisa Boström-Einarsson, the study lead author.
At present, CoTS are being killed by divers using 10-12 ml of ox-bile. Aside from the rarity of this substance, it is also expensive, necessitates permits and should be at a certain concentration.
CoTS contribute greatly to the coral cover destruction in the Great Barrier Reef that scientists were alarmed by the massiveness of the recent outbreak.
In the Great Barrier Reef alone, about 4-12 million CoTs are lurking in the waters. Each female starfish can produce about 65 million eggs during only one breeding period.
In 2014, authorities were able to kill approximately 350,000 CoTS using two complete boat crews, said Boström-Einarsson.
Photo: Thomas Quine | Flickr