Dive Into Your Imagination

Did you know that tropical coral reefs extend down to 500 feet? Richard Pyle has dedicated much of his research to purely studying these deep reefs. He is also an icthyologist (someone who studies fish) interested in how some fish pretend to look like something they’re not!

What is a deep reef and why is it special?
The word "deep reef" means different things, depending on the context. There are extensive cold-water coral reefs that occur in very deep water, but these are not the habitats that I study. The deep coral reefs that I'm interested in are the deeper portions of shallow tropical coral reefs. What most people think of as "coral reefs" -- dominated by large stony table and branching corals -- represents only the shallowest 20% or so of the full extent of tropical coral-reef habitat. The remaining 80% -- spanning depths of about 100-500 feet deep -- are typically dominated by soft corals, sponges, other encrusting invertebrates, and fishes.

The reason these deep coral reefs are special is that they represent the transition zone between the brightly-lit shallow reefs, and the perpetually dark depths. Most of this depth range (200-500 feet or so) remains almost completely unexplored, so there are many, many species new to science inhabiting this realm.

Sounds like there is a lot to learn from this environment! What types of things have you studied and learned?
Most of our work has focused on discovering and documenting new species of fishes, and we are now expanding our focus to collect invertebrates. Documenting new species is of fundamental importance because biodiversity in general is the Earth's most precious and irreplaceable resource (by far!), and we may be losing it faster than we are able to document it. You can't know that a species has gone extinct, if you don't know it exists in the first place. Every species on the planet has its own unique story to tell, so when a species goes extinct, it's like burning the last copy of a book, and if an undiscovered species goes extinct, it's like burning the last copy of a book that nobody has had a chance to even skim through, let alone read. This means there's no way to know what we're losing. Part of the lost information is hidden within the genome; but other important information exists within the community structure – the assemblage of different organisms within a particular habitat and location. Even if we had complete genomes of all species on Earth, we could not bring them back if we don’t know where they lived, and how they interacted with other species. Because of these reasons, we have started to investigate community assemblages and global species distribution patterns in addition to documenting species.

As you have mentioned, a lot of your research on the deep reef has involved fish, so you are an expert! What is mimicry and hybridization in fishes?
Mimicry is a way fishes protect themselves or trick their prey. They do this by one organism closely resembling a completely different organism. There are many, many examples in fishes. Sometimes, one species without toxin in its tissues resembles another species that does have toxin, so predators won't try to eat it. Other times, fishes mimic other organisms -- such as crabs or sea-urchin spines -- to avoid being eaten. And sometimes, several species all look the same, which allows them to form mixed-species schools that are much larger than what they would be if each species looked different (schooling is a way fishes protect themselves from predators). Predators use this trick too! A predator fish will resemble a non-predator, in order to get closer to its prey. I think that mimicry is one of the most fascinating phenomena in all of biology!

Hybridization is when two different species inter-breed and produce offspring that are half one species, and half the other. In many cases, these hybrid offspring are unable to reproduce; but in some cases, they can! For someone like me who studies taxonomy (how organisms are related to one another) and names new species, hybrids are very interesting because they are usually between very closely-related species, which are undergoing the process of becoming separate species. This is one way new species arise, and so these animals are markers to speciation events in progress.

In order to study these types of fish and other organisms on the deep reef, you must need special equipment. What do you use to dive the deep reef? What other techniques do you use in your research?
I use mixed-gas closed-circuit re-breathers, which are different from SCUBA because they recycle the exhaled breath, remove the carbon dioxide, and replace the oxygen before the same breath is inhaled again. Because there is no gas wasted with each exhaled breath, they are much more efficient than SCUBA. A small cylinder of oxygen will allow me to stay underwater for several hours, even down deep. It also makes it much easier to work with gas mixtures that include helium and different concentrations of oxygen, which are particularly useful for deep diving.

In my research I use computers in a number of different ways. I spend a lot of my time developing computer databases of information about species, specimens, and many other things. Getting this information into computer databases allows us to distribute it and interconnect it through the internet. I also use computers to manage things like digital color images and videos of the organisms we discover and study. Computers have proven to be an extraordinary tool for organizing and accessing information quickly and
efficiently.

We hear a lot about threats to the shallow tropical reef. Is the deeper part of the reef in the same amount of danger?
Because we know so little about these deeper coral reefs, we can't say for
sure to what extent the deep reefs face the same threats. The limited
information we have concerning things like shifting temperature patterns and
acidificaton levels, suggests strongly that they are equally imperiled.

The most important thing to remember when it comes to protecting the ocean and the reefs is to learn and understand the threats that face the ocean and its inhabitants. Becoming aware of the issues is the first step to caring about the issues. People won't protect what they don't care about. I love the ocean because it's exciting, mysterious, wonderful, and above all, vitally important to the entire planet. Because of our terrestrial bias as humans, we don't realize how much our own existence utterly depends on the ocean -- for the air we breathe, the food we eat, and, of course, the water we drink.

Finally, what is your favorite ocean animal?
My favorite ocean animal is a little fish with orange polka-dots and a large
yellow head, which I discovered on my first really deep dive. When I first
found it, I didn't even know what family it belonged to. It later was given
a scientific name by some colleagues at the Smithsonian Institution:
Belonoperca pylei.

Biography:

Dr. Richard Pyle is a researcher at the Bishop Museum in Honolulu Hawaii. He studies deep coral reefs as well as the biogeography, hybridization, and mimicry of marine fishes. His research has taken him all over the world, including Palau, Papua New Guinea, American Samoa, Rarotonga, and more. He received his B.S. and Ph.D. in Zoology from the University of Hawaii at Manoa, Honolulu and since then has contributed to much research and published a multitude of articles.

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