//
you're reading...

Biology

Coral Microbiome Health: There’s no probiotic yogurt for that

 

The Paper: Ziegler M, A Roik, A Porter, K Zubier, MS Mudarris, R Ormond & CR Voolstra. 2016. Coral microbial community dynamics in response to anthropogenic impacts near a major city in the central Red Sea. Marine pollution bulletin 105:629-640.

 

The Expanding Importance of The Microbiome

It is nearly impossible to read an article or watch a program on human nutrition without hearing about how important it is to maintain a healthy microbiome. An individual’s microbiome is the community of microscopic organisms (bacteria, fungi, viruses, etc.) that thrive in and on our bodies and help us fight disease, digest food, and even remove waste products to allow more efficient use of the food we eat. A degraded microbiome has been associated with numerous diseases such as multiple sclerosis, diabetes (types 1 and 2), allergies, asthma, and even cancer. Because of this, scientist have worked extensively to accurately document the human microbiome, what makes it healthy, and how to use this information as an indicator of possible health problems before they become serious.

Figure 1. Healthy coral reef (Source: Zak Kerrigan)

Figure 1. Healthy coral reef (Source: Zak Kerrigan)

Only recently have scientists gone beyond humans to study the microbial world living in and on other organisms, and it is becoming increasingly evident that we have only scratched the surface of how important microscopic organisms are to our macroscopic world. In this case, a team of scientists from Saudi Arabia and the United Kingdom, led by Dr. Maren Ziegler, have conducted a study on coral communities in the Red Sea. They have studied the microbes (specifically bacteria) that reside on two different coral species under varying degrees of human impact (sewage discharge, municipal water runoff, and ongoing coastal construction) in order to determine what effect we may have on the health of coral reefs, and how to mitigate further loss of corals to disease and bleaching. Just as our microbiome is affected by the things we put into our bodies, a coral’s microbiome is affected by the water in which it lives and just as in humans, a degraded microbiome can be an indicator of something far more serious.

The Science

For this study, Dr. Ziegler and team selected two species of stony corals that are abundant in the Red Sea at three different locations near the Saudi Arabian city of Jeddah. Importantly, this is the first study to look at corals that appeared to be healthy, with no signs of disease or bleaching, among a community where other corals show signs of distress. The scientists were able to define the bacterial community that lives at these locations by analyzing the DNA from the corals and surrounding waters. Bacteria can only broadly be distinguished by looking at them under a microscope (also a very time consuming and painstaking process), but by analyzing the organisms’ DNA, it is possible to tell them apart down to a species-like level. Additionally, new techniques are allowing scientists to explore the ever-expanding microbial world, discovering hundreds to hundreds of thousands of bacterial species in very small samples.

Fig2

Figure 2. Bacterial community of two stony coral species (Acropora hemprichii and Pocillopora verrucosa) under varying human impacts. Corals begin to lose their bacterial “specificity” under these conditions. (Source: Zeigler et al., 2016)

In general, a coral’s microbiome is species specific. This means healthy members of a single coral species will have very similar communities of bacteria across multiple geographic locations, especially the most dominant bacterial species. These bacteria aid the coral by performing metabolic functions such as cycling of nitrogen and sulfur, as well as aiding the coral in adapting to changing environmental conditions. In general, studies indicate that a properly functioning microbiome is essential for coral health and immunity to disease. Previous studies have found that on diseased coral, this community breaks down. The microbiome is no longer coral-species specific, and opportunistic bacteria are able to take over and push aside the beneficial organisms, leaving a very diverse microbial population that is similar across all diseased corals regardless of species and geographic location.

In this study, Dr. Ziegler and her team found that the bacterial communities of the otherwise “healthy-looking” corals in environments impacted by pollutants more closely resembled that of diseased corals rather than typically healthy ones. They had lost their “core” bacterial community and had been taken over by some of the more opportunistic species, that arguably provide no benefit to the coral. This was evident from the fact that the two coral species began to have similar microbiomes, whereas in the samples taken from sites not impacted by human pollutants, the corals maintain a high level of bacterial specificity (Figure 2).

Why Is This Important

Figure 3. Left is a healthy fire coral, while on the right is a fire coral that has “bleached” itself due to environmental stressors. (Source: gizmodo.com)

Figure 3. Left is a healthy fire coral, while on the right is a fire coral that has “bleached” itself due to environmental stressors. (Source: gizmodo.com)

Just as a shift in the composition of the human microbiome can be an indicator of something more serious, it appears that by looking at the microbiome of corals we may be able to predict declining health of the organism. Caught early enough, it may be possible to prevent widespread coral bleaching and disease (Figure 3) by minimizing human impacts to the affected areas.

This study has also shown how directly humans are impacting the world they live in. In some of the samples taken from areas affected by wastewater runoff, the scientists were able to find bacteria from both the human skin and gut infecting these corals. It is quite difficult to ignore or refute the impact humans are having on this planet against such strong, scientific evidence.

Discussion

No comments yet.

Post a Comment

Instagram

  • by oceanbites 3 months ago
    Happy Earth Day! Take some time today to do something for the planet and appreciate the ocean, which covers 71% of the Earth’s surface.  #EarthDay   #OceanAppreciation   #Oceanbites   #CoastalVibes   #CoastalRI 
  • by oceanbites 4 months ago
    Not all outdoor science is fieldwork. Some of the best days in the lab can be setting up experiments, especially when you get to do it outdoors. It’s an exciting mix of problem solving, precision, preparation, and teamwork. Here is
  • by oceanbites 5 months ago
    Being on a research cruise is a unique experience with the open water, 12-hour working shifts, and close quarters, but there are some familiar practices too. Here Diana is filtering seawater to gather chlorophyll for analysis, the same process on
  • by oceanbites 6 months ago
    This week for  #WriterWednesday  on  #oceanbites  we are featuring Hannah Collins  @hannahh_irene  Hannah works with marine suspension feeding bivalves and microplastics, investigating whether ingesting microplastics causes changes to the gut microbial community or gut tissues. She hopes to keep working
  • by oceanbites 6 months ago
    Leveling up - did you know that crabs have a larval phase? These are both porcelain crabs, but the one on the right is the earlier stage. It’s massive spine makes it both difficult to eat and quite conspicuous in
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring Cierra Braga. Cierra works ultraviolet c (UVC) to discover how this light can be used to combat biofouling, or the growth of living things, on the hulls of ships. Here, you
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Elena Gadoutsis  @haysailor  These photos feature her “favorite marine research so far: From surveying tropical coral reefs, photographing dolphins and whales, and growing my own algae to expose it to different
  • by oceanbites 7 months ago
    This week for  #WriterWednesday  on Oceanbites we are featuring Eliza Oldach. According to Ellie, “I study coastal communities, and try to understand the policies and decisions and interactions and adaptations that communities use to navigate an ever-changing world. Most of
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Jiwoon Park with a little photographic help from Ryan Tabata at the University of Hawaii. When asked about her research, Jiwoon wrote “Just like we need vitamins and minerals to stay
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring  @riley_henning  According to Riley, ”I am interested in studying small things that make a big impact in the ocean. Right now for my master's research at the University of San Diego,
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Gabby Stedman. Gabby is interested in interested in understanding how many species of small-bodied animals there are in the deep-sea and where they live so we can better protect them from
  • by oceanbites 8 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Shawn Wang! Shawn is “an oceanographer that studies ocean conditions of the past. I use everything from microfossils to complex computer models to understand how climate has changed in the past
  • by oceanbites 9 months ago
    Today we are highlighting some of our awesome new authors for  #WriterWednesday  Today we have Daniel Speer! He says, “I am driven to investigate the interface of biology, chemistry, and physics, asking questions about how organisms or biological systems respond
  • by oceanbites 9 months ago
    Here at Oceanbites we love long-term datasets. So much happens in the ocean that sometimes it can be hard to tell if a trend is a part of a natural cycle or actually an anomaly, but as we gather more
  • by oceanbites 10 months ago
    Have you ever seen a lobster molt? Because lobsters have exoskeletons, every time they grow they have to climb out of their old shell, leaving them soft and vulnerable for a few days until their new shell hardens. Young, small
  • by oceanbites 10 months ago
    A lot of zooplankton are translucent, making it much easier to hide from predators. This juvenile mantis shrimp was almost impossible to spot floating in the water, but under a dissecting scope it’s features really come into view. See the
  • by oceanbites 11 months ago
    This is a clump of Dead Man’s Fingers, scientific name Codium fragile. It’s native to the Pacific Ocean and is invasive where I found it on the east coast of the US. It’s a bit velvety, and the coolest thing
  • by oceanbites 11 months ago
    You’ve probably heard of jellyfish, but have you heard of salps? These gelatinous sea creatures band together to form long chains, but they can also fall apart and will wash up onshore like tiny gemstones that squish. Have you seen
  • by oceanbites 12 months ago
    Check out what’s happening on a cool summer research cruise! On the  #neslter  summer transect cruise, we deployed a tow sled called the In Situ Icthyoplankton Imaging System. This can take pictures of gelatinous zooplankton (like jellyfish) that would be
  • by oceanbites 1 year ago
    Did you know horseshoe crabs have more than just two eyes? In these juveniles you can see another set in the middle of the shell. Check out our website to learn about some awesome horseshoe crab research.  #oceanbites   #plankton   #horseshoecrabs 
WP2Social Auto Publish Powered By : XYZScripts.com