Zika, psychobiotics and more in reader feedback

Zapping Zika

As Zika virus spreads, researchers are racing to find Zika-carrying mosquitoes’ Achilles’ heel, Susan Milius reported in “Science versus mosquito” (SN: 4/2/16, p. 30). Some approaches include genetic sterilization so mosquitoes can’t reproduce and infecting them with bacteria to decrease their disease-spreading power.

One reader had another suggestion. “Maybe we could just secure some wilderness areas for birds and bats,” Kurt Feierabend wrote on Facebook. “Let the feasting begin.”

“Some bats and birds do eat mosquitoes, but Aedes aegypti mosquitoes, which are Zika carriers, typically dwell in or around people’s houses — not an easy hunting ground for predators,” says Meghan Rosen, who also reported on the virus for this special report (SN: 4/2/16, p. 26). The mosquitoes lay eggs in water though, so predatory fish and crustaceans could serve as a type of biological control. But, according to the U.S. Centers for Disease Control and Prevention, that option may not be practical. Ae. aegypti larvae can  also develop in dog bowls, plant saucers and rain splash left in crumpled plastic bags, Milius notes.

Wandering baby Jupiter

As proto-Jupiter moved through the solar system, it may have absorbed so much planet-building material that it reduced the number of planets that could form near the sun, Christopher Crockett reported in “Jupiter could have formed near sun,” (SN: 4/2/16, p. 7).

“Over what time span would this have occurred, and are any of our planets currently moving in or out?” asked online reader Mark S.

If Jupiter formed close to the sun, it spent only about 100,000 years in the inner solar system, well before the rocky planets started to form, Crockett says. “Researchers suspect that the outer planets danced around quite a bit during their formative years. All the sun’s worlds are now, fortunately, staying put for the foreseeable future,” he says.

Addicted to microbes

In “Microbes and the mind” (SN: 4/2/16, p. 22), Laura Sanders reported on the surprising ways in which gut microbes influence depression, anxiety and other mental disorders. But it’s not a one-way street. “Our behavior can influence the microbiome right back,” she wrote.

Reader George Szynal wondered how addiction to drugs, alcohol and other substances may influence microbes and vice versa. “Can treatments of microbiome enhance and aid the recovery of addicted persons?” he asked.

“That’s a fascinating idea, but so far, little research has been done on this question,” Sanders says. “Alcohol disorders have been linked to changes in the gut microbiome, and smoking has been linked to differences in mouth bacteria. But until scientists figure out whether those microbe changes are consequences or causes of the addictions, we won’t know whether changing the microbes could help people kick the habits,” she says.

Water rising

Without a sharp decrease in carbon dioxide emissions, rapid melting of the Antarctic ice sheet could raise sea levels by 60 meters by the end of the century, Thomas Sumner reported in “Tipping point for ice sheet looms” (SN: 4/2/16, p. 10).

In addition to melting ice sheets, reader Carolyn Lawson asked if human depletion of groundwater also contributes to sea level rise.

About 80 percent of groundwater losses end up in the oceans, according to a recent study in Nature Climate Change. Simulations showed that groundwater contributed about 0.02 millimeters of sea level rise annually in 1900 and increased to around 0.27 millimeters annually by 2000. “Current sea level rise is about 3 millimeters per year, so that’s a pretty large chunk,” Sumner says. “Unfortunately, Earth’s groundwater reserves are disappearing. It’s unclear whether the groundwater contribution to sea level rise will continue to increase indefinitely.”