Tiny creatures with big influence on coral reefs

The coral reefs are renowned for their beauty as well as their diversity. But few people know that most of the diversity found around coral reefs is completely hidden from the naked eye. Welcome to the world of microbes.

Just as humans need a healthy microbiome, a balanced mixture of invisible bacteria, fungi, algae and plankton in sea water is essential to the functioning and health of organisms in coral reef ecosystems.

These microbes are important engines of nitrogen and carbon cycles on reefs, playing a role in maintaining the environment in which a coral lives healthy and balanced.

They are responsible for taking nutrients that would otherwise be inaccessible to plants and animals, such as nitrogen and phosphorus, and transforming them into forms that cells of living organisms use for metabolism and growth.

“These are the unknown heroes of life on earth. And without them, life on coral reefs would stop,” said objectives, Dr Patrick Laffy.

The mystery of what exists and what they do

Despite their omnipresent nature, their diversity and their importance for reef ecosystems, scientists have just scratched the surface of microbial communities in the large coral barrier and their functions.

In addition to recycling nutrients, we know that seawater microbes form the base of food networks, providing energy to ecosystem animals.

There are other complex interactions in progress which aim for scientists who are rummaging.

The Aims researcher, Dr. Yun Kit Yeoh, explained: “Like the diversity of corals on the large barrier barrier contributes to unique functions, the individual functions of each microbe provide critical ecosystem services with coral reefs.

“Identifying important microbes, how they interact with the environment and other reef organizations, including corals

“This is essential for the future of the system and could help other coral reefs.

“We are well placed in order to examine the diversity and roles of microbes. Thanks to our vast collections of water samples in our surveillance programs and long -term data sets on the health of reefs, we can take advantage of existing knowledge and see where microbes are in this complex space.”

Microbial functions in seawater reflect the status of the ecosystem

To understand their functions, the AIMS research team examines the DNA of microbes, defining the first results in an article published in the journal Microbiome.

This work maps the critical microbial genes underlying the productivity of the reef, providing a crucial reference for its future health and management.

Main author and aims @ jcu pH.D. Student Marko Terzin said that the team had analyzed the seawater samples taken from 48 offshore reefs through the long -term GBR surveillance program by AIMS, and found that the functional genes in microbes were a strong predictor of the condition and the health of the reefs.

“Because these microbes play an essential role on coral reefs, their genes as genes are a reflection of what is happening at that time on a coral reef,” he said.

“The analysis of microbial functions of seawater could be extended to indicate additional stressors such as high sea temperatures or additional nutrients in the water column due to a flood or pollution event.”

See the invisible with DNA

Dr. Laffy illustrated the complexity of the task: “We bring together a puzzle of the role of these communities on the reef, where genetic information in sea water is puzzle pieces.

“We are trying to bring this puzzle together without any image guide and the sizes of parts can vary depending on the technologies we use to reveal the parts.

“For this study, we had small raw pieces of the puzzle and determined that the role of genes in the samples we found was more informative of the quality of water, or chemistry, than to know what bacteria they come from.”

A future for monitoring reefs?

Microbial communities are the first stakeholders to change on a coral reef. They quickly react to the changing conditions on reefs and can influence the results for corals because they undergo temperature changes, light intensity changes and chemical variations in water.

Their sensitivity highlights the potential of seawater microbes to be used as indicators of the health of reefs.

“Previous studies have shown that microbes taken from a seawater sample are precious indicators of these changes, even better than microbes in the sand or inside corals,” said Dr. Laffy.

“Since seawater samples are easy to collect, it is possible that we can use microbial seawater communities as a complementary method when monitoring the health changes in reefs.”

Dr. Yeoh said work could help reef monitoring efforts.

“In the future, understanding of microbes could complete our current surveillance efforts, which means that we are able to understand coral reefs in distant or dangerous places for humans, simply by analyzing a water sample,” he said.

“This could be useful in the future for countries with fewer resources for water surveillance in their coral reefs.”

The team is currently preparing to publish more about their research on microbial communities.