by Alex Larson →
Coral reefs around the world are dying off in masses as the seas temperatures continue to grow and the acidity of the oceans rise with it due to climate change. These changes cause the reefs to go through a process known as coral bleaching which happens when warmer water temperatures cause corals to expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white.
When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality.
The worst bleaching event ever recorded happened in 2016 when half the northern Great Barrier Reef died due to mass bleaching due to rising ocean temperatures. In the years spanning 2014-2017, in some areas of the reef temperatures rose as much as 10.8°F (6°C), sometimes lasting as long as eight months.
Unfortunately for the reefs, while all this coral death happened quickly and suddenly, the growth of new coral is at an extremely slow rate as they take hundred and thousands of years to grow back to what they once where and this is not good.
The best solution to save reefs is to prevent future warming of the oceans but researchers are attempting to help regrow some of the reefs that are already dead and they are using some pretty cool technology to assist them.
Researchers at two Australian universities have developed and underwater robot named Larvalbot that is designed to move autonomously along dead or damaged sections of the reef with hundreds of thousands of microscopic baby corals.
“This year represents a big step up for our larval restoration research and the first time we’ve been able to capture coral spawn on a bigger scale using large floating spawn catchers then rearing them into tiny coral larvae in our specially constructed larval pools and settling them on damaged reef areas,” Professor Harrison said whom engineered the robot.
“With further research and refinement, this technique has enormous potential to operate across large areas of reef and multiple sites in a way that hasn’t previously been possible. We’ll be closely monitoring the progress of settled baby corals over coming months and working to refine both the technology and the technique to scale up further in 2019.”
The team recently tested the bot on the outer part of the GBR. along the northeastern coast. The trial run dispersed 100,000 baby specimens that were collected from coral that survived the bleaching event of 2016-2017. This coral was specifically chosen as research as revealed that the coral that survived the mass bleaching actually adapted to become more resilient to heatwaves and rising temperatures.
The hope is the that future versions of the robot will be able to disperse millions fo baby corals to speed up the regrowth process of reefs but the team is still waiting on research to show that the coral will take hold and grow.
“We can’t actually see the results of these experiments until we start to see juvenile corals grow — so, for at least six to nine months,” Harrison said. “What we’ll be doing now is monitoring the reef over the coming months.”
Harrison hopes to eventually develop a fleet of LarvalBots that would be used to repopulate reefs around the world, though he is unsure how much such a project would cost.
While this is a great idea to try and promote growth on reefs that have already been killed, the most important thing we do today is to do everything we can to reduce coral bleaching so the bots are never needed. Due to the size and scale of coral reefs across the planet, it is essentially impossible to regrow all shallow water reefs if bleaching is to continue.
To accomplish this, we must slow the rate of climate change and protect the oceans from warming up.