On May 1, the Environmental Protection Agency (EPA) has approved an experimental use permit that allows the British biotech company Oxitec to release genetically modified mosquitoes into the Florida Keys as well as Harris County, Texas, where Houston is located.

The insects are being released to kill off the type of mosquitoes that carry the Zika virus -the Aedes aegypti. According to the Centers for Disease Control (CDC), the Zika virus can cause a birth defect called microcephaly (underdevelopment of the brain) if a pregnant woman gets bitten by a carrier.

Since the female mosquitoes are the ones who bite people, they are the only real threat for spreading the virus. Oxitec developed a male mosquito with a modified gene that kills off any of its female offspring before reaching adulthood. The idea is that after the new males grow up, they then mate with more females as the cycle decimates the Aedes Aegypti population.

The EPA released a statement backing the move saying: “To meet today’s public health challenges head-on, the nation needs to facilitate innovation and advance the science around new tools and approaches to better protect the health of all Americans.”

The permit, which lasts for two years, requires Oxitec to “monitor and sample the mosquito population weekly.”

“EPA has also maintained the right to cancel the (permit) at any point during the 24-month period if unforeseen outcomes occur,” the statement added.

“Continual, large-scale releases of these OX5034 GM males should eventually cause the temporary collapse of a wild population,” Oxitec said.

But the initiative has been met with local opposition. The Florida Keys Environmental Coalition is trying to stop the release from happening.

“We have repeatedly asked for Oxitec to work with us to prove the technology is safe,” Barry Wray, executive director of the Florida Keys Environmental Coalition, said in a statement in 2018 following a second permit attempt by Oxitec.

“Instead of receiving Oxitec’s cooperation to provide this confidence, we have witnessed a pattern of avoidance, misrepresentations, obfuscations and using marketing and political influence to persuade the regulatory and community stakeholders to proceed with what is truly a poorly designed experiment on our public and ecosystems,” Wray added.

The Texas releases are not scheduled until 2021. The permits still require local approval before the release can be finalized.