By Kelsey Nowakowski, St. Thomas Source
Over the last decade, shallow-water reefs have bleached and died off at alarming rates around the world. While this global trend continues, little attention has been given to deepwater reefs even though they’re faring much better as ocean temperatures warm.
Since deepwater reefs are largely still intact, scientists think it makes sense to protect them now to increase the chances of them staying that way. But they’re difficult to conserve, since not much is known about them, including their locations.
To fill that knowledge gap, marine scientists such as Viktor Brandtneris at the University of the Virgin Islands are developing thrifty and widely accessible techniques to study hard-to-reach reefs. Last week Brandtneris spearheaded a crowdfunding campaign to raise funds to buy a key piece of equipment that will greatly expand the project’s research capacity.
“How can we protect reefs if we don’t know where they are?” Brandtneris asked. “The current storyline about coral reefs is horrendous and lacks hope, but there are incredible living reefs doing well that we need to learn more about.”
Deepwater reefs aren’t visible from the surface, making them of little interest to most people, but they still offer a host of economic and biodiversity benefits. A number of commercially important fish species spawn in Mesophotic reefs, which are what these coral ecosystems are called between about 100 and 400 feet below the surface. Referred to as the “lifeboats” for corals, they also could be key to repopulating coral when shallow-water reefs die.
To put things in perspective, as much as 70 percent of coral reefs between the surface and 100 feet deep have bleached and died in the last 20 years versus only five percent of reefs between 100 and 250 feet. Shielded from warm temperatures, waves and ultraviolet light, deepwater reefs offer a glimmer of hope for the survival of these important ecosystems.
With a potential of more than 1,200 square kilometers of Mesophotic reefs surrounding St. Thomas and St. John, there’s a great deal of research to be done to understand their distribution, health and other characteristics.
But diving these deepwater reefs is costly. It takes large boats, expensive equipment, technical dive experience and lots of time. Brandtneris said that he and his colleagues were left wondering how to afford this type of research.
They decided to get thrifty by essentially putting two GoPro cameras in a deepwater housing and tying them to a reel. They drop the cameras, which in total weigh about 30 pounds, to a depth of 300 feet to take pictures of what’s there. Prior to this, they chose dive sites based on often incomplete ocean mapping data that could lead them astray.
An image of a coral reef at 128 feet, captured using the first version of our camera system.
An image of an Agaricia coral reef at 225 feet, captured using the second version of our camera system.
Brandtneris said there have been dives where they’ve gone down a couple hundred feet only to see sand where they’d hoped to find coral. That’s a significant loss of time and resources, since a diver can stay at a depth of 225 feet for only 20 minutes and it takes three times as long to come back up. And those deepwater dives cost about $300 each.
“The idea was to make something cheap, simple and widely available, so we could afford to go study more of these reefs,” Brandtneris explained.
Using the cameras comes down to economics: The photos allow them to cover more underwater area and help them decide where to spend energy diving. Though its design is simple, Brandtneris said it’s greatly increased research capacity and that the pioneering use of “GoPros on a string” has applicability outside of the Virgin Islands.
An example of the data produced using the drop camera methodology. Figure taken from Smith et al. 2016
“This helps us access places without much infrastructure for doing this type of research, especially small islands in the eastern Caribbean that can be hard to get to and work in,” Brandtneris said. “They often don’t have access to marine research programs, boats or technical diving.”
Last month Brandtneris and other University of the Virgin Islands colleagues surveyed and processed data from more than 300 sites surrounding Montserrat in 21 days. Without the cameras, it would’ve taken the team 75 days just to do the surveys. The data they collected will help the island decide which marine areas to protect, since little to nothing was known about its deepwater reefs before—the only reference map they had was a British Royal Navy survey circa the late 1800s. Australian scientists have also expressed interest in using this technology.
On an average day, six people can survey about 40 sites with the cameras—which overall is about 90 percent less expensive than diving each site. The cameras have to be pulled up by hand, though, which tacks on about four to six minutes for each survey.
To cut down on this time, Brandtneris is trying to raise $5,050 to purchase an electronic reel, which can pull up to 300 feet of line per minute. With this reel, two people could cover about 70 sites a day and for every 10 sites, they’ll save 50 minutes. The project now has a crowdfunding site that’s accepting tax-deductible donations to reach the funding goal.
“These funds will be used to speed up our sampling, reduce our costs and increase the breadth of data we can collect,” Brandtneris said. And, the pictures they take will help show that the state of the Caribbean’s coral reefs isn’t all doom and gloom.
This article was reposted with permission from St. Thomas Source.