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The Reef Damsel’s Distress Call

Researchers at James Cook University in the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) have uncovered an interesting feature of the Damsel reef fish family. We watch our fish dart in and out of crevices when they get scared in our aquariums but little did we know they are, at the same time, releasing a chemical signal from their skin and scales to ward of predators, and give themselves a fighting chance for survival. This is a finding not new to the science of fish, but the surprise conclusion was the benefit to the fish releasing the chemical: “When damselfish release their chemical alarm on a coral reef, lots of additional predators are attracted to the cue release area,” says Professor Mark McCormick from the Coral CoE. 151027213415_1_900x600The added presence of predators would seem counterintuitive to anyone reading this, but what researchers would like us to recognize is the increased presence of predators can cause confusion at the predation site, allowing the fish that released the chemical signal additional distraction for escape. “When caught by a predator, small damselfish have almost no chance of escaping their fate as the predator’s next meal. However, when another fish predator is attracted to the capture site, prey will escape about 40 percent of the time,” added Professor McCormick. “For decades scientists have debated the evolutionary origin of chemical alarm cues in fish,” says study lead author, Dr. Oona Lönnstedt, now a research fellow at the University of Uppsala. The percent increase of escape establishes additional evolutionary benefit to the defense mechanism of Damsel fish, while opening a new avenue for understanding the behaviors of reef fish. Read the entire article here!… More:

Pohnpei Deep Dive

Pohnpei reef - reefs

Pohnpei reef, credit Sonia Rowley

 Check out this new video from Brian Greene – a glimpse into what an extremely deep diving trip looks like. You’ll notice that the divers’ voices sound funny; that’s because they are breathing a mixture of oxygen and helium. The main reason for adding helium to the breathing mix is to reduce the proportions of nitrogen and oxygen below those of air, to allow the gas mix to be breathed safely on deep dives. A lower proportion of nitrogen is required to reduce nitrogen narcosis and other physiological effects of the gas at depth. And the crunching sound isn’t the scientists stepping on the reef – it’s actually the  desiccant packs in the camera housing.  Brian Greene, Dr. Richard Pyle and Dr. Sonia Rowley are on this dive, part of the Association for Marine Exploration‘s expedition to Pohnpei, Ant Atoll, and Pakin Atoll. As Dr. Rowley posted on the site, “After our remarkably successful 2014 research expedition to Pohnpei and Ant Atoll, it was clear that we simply had to return…”… More:

An Overview of Marine Fungi and Their Ecological Roles

A Labyrinthula-infected eelgrass frond.

A Labyrinthula-infected eelgrass frond.

 Sometimes regarded as rare or insignificant, marine fungi are both phylogenetically and ecologically diverse. Like all fungi, marine fungi are heterotrophic. Although a large portion of marine fungi are saprobes – organisms that feed on decaying organic matter, many species of marine fungi form symbiosis with living marine animals. While some of these relationships are best described as parasitism, there are many cases of mutualism as well. One study investigated the secondary metabolites produced by marine fungi participating in symbiotic relationships with sponges. This study revealed that symbiotic marine fungi produce chemicals that may assist their sponge host in staving off pathogens (Höller et al., 2000). Although these species of marine fungi (and many others) facilitate… More:

Astreopora montiporina the backstory

The story of my Astreopora montiporina colony is an interesting one. If you’re not familiar with this coral don’t worry, it is not commonly known or collected; it was named as a new species in 2011. Back to my story, I purchased a colony of clove polyps four years ago and when I was making some fragments I noticed that the rock the clove polyps were growing on was not a rock but the underside of a browned out coral colony. I removed all of the clove polyps, turned the coral towards the light, and waited to see what would happen. During the following months it slowly started to recover, the color changed from brown to green. After about a year it looked like this. 


Astreopora after about a year of recovery

 I didn’t know what kind of coral it was; the growth… More:

Coral Letters

coral lettersTwo years ago, Barry and Aimee Brown began photographing “hidden” letters in the brain coral colonies around Curacao, the Caribbean island where they live. Their hunt, which sometimes took them as deep as 100 feet, gave them an even better understanding of the devastation shallow-growing brain coral have experienced from bleaching and recent strong storms. You can download the full set of letters for free here as a zip file. The photographers only ask that you give them credit and that you don’t use the work commercially.… More:

Neptune Systems Par Monitoring Kit

neptune systems PMK
Neptune Systems is pleased to announce that it will begin shipping its new Par Monitoring Kit, priced at $299.95, to North America next month. For more information, go to:

Study Shows Corals Consume Microplastics

Unfortunately, the solid plastic trash we often see in the ocean (bottles, bags, etc.) is only a portion of the plastic waste that has been deposited there. A considerable amount of waste may be present in the form of microplastic. Microplastics are basically miniscule bits of plastic that can be suspended in the water column. Though the environmental effects of microplastic pollution are not yet well understood, the consensus among marine biologists is that they pose a global threat to marine ecosystems. Researchers from the ARC Centre of Excellence for Coral Reef Studies at James Cook University set out to see if corals (which are non-selective filter feeders) ingested microplastics. Corals from a clean area were placed in a contaminated area. After two nights, they were analyzed for the concentrations of plastics. Results indicated that the corals consumed plastic at a rate only a little lower than that of their natural planktonic food. Plastic materials were found engulfed in digestive tissue, suggesting that it may hinder a coral’s ability to digest its food. The team is now investigating what… More:

Aging Bony Fish

Pair of otoliths.

Pair of otoliths.

When conducting studies, many ecologists are posed with the question: How old is this fish? Because size is rarely a fair indication of age, the use of a more precise method is often required. The most prevalent method of aging bony fish is known as Otolith Analysis. This procedure entails the extraction and microscope analysis of the fish’s otoliths – small calcium carbonate structures that are located slightly posterior to the fish’s eyes. 
An otolith with visible annuli.

An otolith with visible annuli.

 These structures, which are used as gravity, balance, and movement indicators, grow continuously throughout a fish’s life and exhibit a unique growth pattern. This growth pattern is thought to be a result of seasonal temperature changes – during the winter, the otoliths grow slowly, accreting lightly-colored calcium carbonate; during the summer, the otoliths grow quickly, accreting darker calcium carbonate. The contrast between lighter calcium carbonate and darker calcium carbonate forms rings known as annuli. Since each annuli represents one year, scientists may determine the age of the fish by counting them.… More: is the world's leading destination for sustainable coral reef farming and the aquarium hobby. We offer a free open forum and reef related news and data to better educate aquarists and further our goals of sustainable reef management.