Keeping an eye on coral health

Coral bleaching is a devastating global issue. If temperatures continue to rise, the rate of bleaching events will increase, threatening corals’ survival.

The first global assessment of the impact of climate change on coral reefs, published in 2017 by UNESCO, revealed that coral reefs in all 29 reef-containing World Heritage sites would cease to exist as functioning ecosystems by the end of this century if greenhouse gas emissions continued at their current rate.

CoralWatch citizen science project is aiming to change that.

The program, based at the University of Queensland, is promoting healthy reefs by engaging the global community in monitoring coral health and coral bleaching.

The effort is based on a simple tool, the Coral Health Chart. There are four different colour bands on a waterproof chart. It’s a simple process of observing the coral and matching the colour and then report your findings.

When you sign up, CoralWatch will send you a hard copy of the chart, printed on a specific type of plastic with specific inks and colours that are consistent across all supplied charts.

“CoralWatch is like a paint chart and people can very easily match it to the coral. It’s pre-calibrated, working with coral scientists and their standardised bleach sequence,” explains project leader Justin Marshall.

“Photographs are great for coral cover, general assessment, but it’s not good for matching colour because everyone’s camera, computer monitor and printer are all different. So, it becomes a nightmare if you’re trying to standardise things.”

201116 divers on the reef
Credit: CoralWatch

The project started almost 20 years ago when on a visit to Heron Island in 2002, Marshall noticed the reefs were different colours, sometimes dark brown, sometimes pale.

“I started talking to scientists who were working on the reef, and they explained it’s probably this bleaching thing,” he explains.

With the help of reef scientists and other researchers (including a chicken vision researcher – who helped with colour and printing), they came up with the Coral Health Chart system.   

Since then, the chart has been made available in 12 different languages. The data is then used in scientific analysis and can also be used in the classroom. The data, covers more than 300,000 corals on more than 1920 reefs in 79 countries, is also publicly accessible online.

To get involved with the reef monitoring, head to the CoralWatch website, apply for a Coral Health Chart (first one free, $5 per chart after that) and then jump into the water and get colour matching. Record your observations before reporting them online or via the smartphone app.

For those of you who can’t visit a reef, Marshall says there’s still plenty you can do.

“Even if you can’t get to a reef, we can help you think about it. Thinking about it is useful because you can still do something about bleaching, and also be informed about what’s going on.”

The real issue that needs to be addressed, Marshall says, is climate change. Making small changes, such as minimising waste, travelling smarter and being energy efficient, can all help protect our reefs by addressing the larger issue of climate change.

“By picking up a little grain of earth and putting it somewhere else, we can build a great pile in a short space of time,” he says.

As for the future of CoralWatch, Marshall says he hopes the project fails.

“In the end, CoralWatch doesn’t need to be here,” he says.  

“The real reason it’s here is because the reef is failing, and we need to keep an eye on that. I’d love to see that reverse. I don’t want there to be a need for people to monitor it other than a general interest in coral.”

We’re interested to hear about citizen science projects. If you know of, or participate in one, let us know by tagging us @cosmosmagazine on Twitter or by emailing us at [email protected]

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