In our last blog post, we discussed deep-water coral reefs, their importance to the ecosystem, and the dangers they face. Today, we’re going to build on that and explore a recently discovered reef that lurks in the depths of Northern Australian waters.
What’s The Big Deal?
The reef, which is unnamed, is hidden in the deep water behind Australia’s Great Barrier Reef. It was discovered by a joint effort of James Cook University, University of Sydney, and Queensland University of Technology utilizing aircraft and Light Detection and Ranging (LiDAR) lasers to create a 3-D map of the seafloor. A new reef normally wouldn’t turn many heads, but this one is comprised of over 6000 square kilometers of deep-water corals that were hiding in plain sight.
Unexplained doughnut-shaped mounds measuring 200 to 300 meters across and 10 meters deep make up a large part of the reef, and they have scientists excited about the potential for further discovery and biodiversity. These creatures have been identified as bioherms, or ancient organic reefs made of marine invertebrates such as coral, echinoderms, gastropods, and mollusks.
Halimeda is a calcareous algae, or a type of algae with a skeletal material that is composed of calcium carbonate. The hidden reefs’ bioherms are comprised of Halideda, which provide excellent support for reef’s “backbone” and also become integrated into the reef when they die. Scientists are speculating that the bottoms of the Halimeda mounds serve as a graveyard for marine life, and it’s very likely that they can give clues into the area’s past climate and environmental changes. It’s hoped that this will give us a better understanding of the Great Barrier Reef’s lifespan and help scientists determine which changes in the reef are natural and which are caused by humans.
Isn’t it Just an Extension of the Great Barrier Reef?
No. Think of this new reef as the building block upon which the Great Barrier Reef is built. The algae and smaller organisms of the deep water reef help provide a nutrient-rich ocean floor for the Great Barrier Reef, and they also migrate into the larger reef to become part of its food chain. This means that while this is, in fact, a separate reef system, its proximity has made it a part of the same ecosystem.
A study of deep water reefs off the coast of the Southeastern United States, conducted by Florida Atlantic University, showed diversity not only among invertebrates, but also among fish species of all sizes. It’s reasonable to conclude that fish are also migrating between both reefs, following the flow of food that inhabits the reefs.
If They Are So Similar, is The New Reef Safe?
Unfortunately, the answer is no. Ocean acidification, resulting from the carbon dioxide that humans have introduced into the atmosphere, has the potential to stop all growth. The Halimeda bioherm relies on calcium to expand and continue life. Extra carbon dioxide in our atmosphere reduces the ocean’s amount of carbonate ions, which makes it impossible for calcification to occur. It’s an issue with potential to have far reaching implications on the food chain of our entire planet.
As reef enthusiasts, we encourage everyone to be conscious of climate change. We love our reefs and enjoy growing them in our tanks, but we do not want our tanks to be the only place a reef exists. We encourage our readers to spread the word about marine discoveries to educate people about the wonder of our oceans and what needs to be done to protect them.
We hope this article has sparked some interest about our favorite marine invertebrates. If you’d like to learn how to start your own reef, contact us. We have a wide selection of reef centric lights to help get you started.