Parrotfish Vindicated

Guest Post by Willis Eschenbach

Four years ago I wrote a post called “The Parrotfish Should Be The National Bird“, about the critical place that the parrotfish plays in the life of both the reef and the coral atolls that depend on the reef. It was based mostly on my years of scuba and snorkel diving on the coral reefs of the South Pacific and watching the reef denizens including the parrotfish go about their daily lives.

white-sand-beachAs a result, I was glad to see a press release from last week entitled Study finds parrotfish are critical to coral reef health. In it, they analyzed sediment cores that were dated back almost to 1000 BC. Their results showed that the parrotfish, which graze on the algae that would otherwise overgrow the reef, are a critical part of the reef ecosystem. I did have to laugh about this paragraph, though …

“These findings reveal that parrotfish indeed have a positive and critical role in coral health, a hotly debated issue in coral reef research that cannot be resolved with studies of modern reefs which have already been greatly altered by human activities,” said Cramer. “Using the fossil record to analyze the natural state of reefs before human disturbance, we have conclusively shown that if we want to protect corals we have to protect the parrotfish from overfishing.”

The importance of parrotfish might be “a hotly debated issue” in research circles … divers, on the other hand, hang out underwater and watch the circus.

The only part that they didn’t mention in their analysis was that when the parrotfish graze the algae off the reef, they also bite off part of the coral. These chunks of coral are ground up by special plates in their throats, and excreted as a lovely white sand … the lovely white sand that you see in the pictures of tropical beaches.

So if you go to a tropical island, walk by the ocean, enjoy the white sand beaches, and please don’t eat the parrotfish …

Best to everyone,


As Is My Custom—I ask that in your comment you QUOTE THE EXACT WORDS YOU ARE REFERRING TO, so that we can all be clear about your subject.

Previous Posts on Atolls and Parrotfish—

Floating Islands 2010-01-27

Much has been written of late regarding the impending projected demise of the world’s coral atoll islands due to CO2-caused sea level rise. Micronesia is suing the Czech Government over CO2 emissions that they claim are damaging their coral atolls via sea level rise. Tuvalu and the Maldives are also repeating…

The Irony, It Burns … 2010-06-03

Anthony commented yesterday on the question of atolls and sea level rise here, and I had previously written on the subject in my post “Floating Islands“. However, Anthony referenced a paper which was incorrectly linked by New Scientist. So I thought I’d provide some more information on the actual study, entitled “The dynamic response of reef…

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January 29, 2017 10:26 pm

No doubt they acknowledged your writings?
Thought not.

Reply to  martinbrumby
January 29, 2017 10:47 pm

I bought a book of insults not long ago. Full of witty clever insults by people who “have a way with words.” You on the other hand….. stick to the Net where publishing is free. No one would pay good money to read pathetic insults like yours. (Or mine I suppose.)

Gareth Phillips
Reply to  Doug
January 30, 2017 2:04 am

I will defend Willis’ insults with my dying breath. They are crude and offensive, but of a durable nature and numerous. A bit like a WW2 Soviet tanks. This site would be a much more boring blog without Willis’ incisive writing and notoriously short fuse. Long may it continue!

Reply to  Doug
January 30, 2017 2:49 am

Did Willis insult someone?

Reply to  Doug
January 30, 2017 3:29 am

No no! I was referring to matinbrumbys feeble missive. I’m a big fan of Willis.

Reply to  Doug
January 30, 2017 4:09 am

What are you on about?
My guess is that the authors of this study (the full version of which I haven’t seen) were likely aware of Willis’s writings but forgot to credit him.
If you think that’s the best I can do in the insult department…….

Reply to  Doug
January 30, 2017 5:37 am

You need to take some lessons in sarcasm, as you appear to have completely misunderstood martinbrumby’s post.

Ben of Houston
Reply to  Doug
January 30, 2017 11:36 am

Doug, from the phrasing, I think Martin was doing this as “of course those jerks didn’t acknowledge Willis’s prior data”.
Martin, you should probably make your wit less ambiguous. Saying “No doubt those layabouts acknowledged your writings” or something of the sort would have made it much more clear.

Reply to  Doug
January 30, 2017 12:00 pm

Doug …. Martinbrumby was ‘insulting’ the authors of the coral reef paper, not Willis. Read his comment again.

January 29, 2017 10:39 pm

Congratulations, Willis.
I’ve often cited your analysis of parrotfish’s essential role in minimizing wave erosion of sandy beaches and maintaining healthy coral reefs.
I’ve also gotten a lot of laughs when telling people that the beautiful sandy beaches they’re enjoying are actually mostly comprised of parrotfish poop…

George Tetley
Reply to  Willis Eschenbach
January 30, 2017 3:49 am

There is a very good reason that Parrot Fish never gets on the menu, Yuk !

Reply to  Willis Eschenbach
January 30, 2017 4:07 am

They are messy, noisy eaters, no table manners, but they do the job.
Well done again, Willis, guess nobody paid you for that research. Can we accuse them of parroting earlier research?

Reply to  Willis Eschenbach
January 31, 2017 8:59 am

At Hanauma Bay, I discovered that parrot fish a like sea going puppy dogs, especially if they have been hand fed.

January 29, 2017 11:36 pm

This is one of those pieces of information I was taught in Oceanography class decades before ever hearing the name Willis Eschenbach and also wrote and edited a piece for the Cousteau Society on the subject back in 1991. Apparently this has been forgotten by the entire community of oceanographers.
Similar to how I learned in the 1970’s in high school that the three phases of water provided negative feedback to keep our planet at a viable temperature, also a fact apparently forgotten by the Earth Science community..

Reply to  Charles Rotter
January 30, 2017 12:13 am

Yes, earth has a natural refrigeration system with water as the working fluid.

Reply to  crosspatch
January 30, 2017 3:26 am

Any thoughts regarding this article
It seems our prevailing understanding of how evaporation works might be incorrect. This would have big implications for computer models of the climate.

John F. Hultquist
Reply to  crosspatch
January 30, 2017 4:56 pm

@ Jack Simmons 3:26
Toward the end of the article, I see:
Contrary to common belief, the most abundant greenhouse gas in the atmosphere of our planet is not carbon dioxide but water vapour.
The hitherto evaluation of the rate of evaporation of the oceans must therefore be subject to error, …
I don’t believe either of these are new insights. Maybe the authors have to publish n papers a year to get a raise or stay employed. They may have fine-tuned an equation regarding evaporation but the CAGW industry has moved on to social justice issues. Maybe if they rewrite the title and last paragraph, then send to a different journal, they can get one of the n papers checked off for 2017.

Wim Röst
Reply to  Willis Eschenbach
January 30, 2017 2:17 am

Willis Eschenbach: “Their place in actually creating the beaches of the atolls, on the other hand, is nowhere near as widely known.”
When I first saw a parrotfish crunching the coral I thought they were damaging the coral. It took many years before I realized that they were helping to ‘build islands’. The fine (I suppose) white coral sand they produce is easily brought to the beaches by the waves and makes the islands rise as sea level rises. As Darwin said that happened.
Besides damaging the corals with dynamite and taking the sand for construction, fishing parrotfish is the third negative influence of man on the natural growth of islands.
After using dynamite to gather coral Ithe beach near my hotel n Bali did disappear in one or two decades and the coral is now subsituted by some concrete structures made by cement. Very ugly. They told the coral was used to produce cement. I checked whether ‘using coral to make cement’ was possible and found this one minute video:

Alan Watt, Climate Denialist Level 7
Reply to  Willis Eschenbach
January 30, 2017 4:29 am

Their place in actually creating the beaches of the atolls, on the other hand, is nowhere near as widely known.

I was taught the role of parrotfish in maintaining the reef in 1980, either in my basic scuba class, or on the trip I took to Bonaire later that year. This was before the BNMP (Bonaire National Marine Park) authority was established, so divers pretty much policed themselves. Certainly the diving community was well aware at that time.
One sign of a healthy reef is the sound of lots of parrotfish feeding off the coral; it’s a steady background noise.

Reply to  Willis Eschenbach
January 30, 2017 6:12 am

Recently an alternative mechanism for formation of many coral atolls has been published…
Gate keeping and peer review didn’t keep it out of the journals and general acceptance, even though it overturned the ideas of the great man Darwin…
an object lesson in how science progresses.
For homework you can google for the absolutely fascinating new explanation.

Reply to  Willis Eschenbach
January 30, 2017 8:27 am

Re below: Concentrated chlorides (through evaporation) and rounded grains weaken concrete made of beach sand; I am told

Reply to  Willis Eschenbach
January 30, 2017 11:36 am

Wim and Willis, you are both right. Coral is almost pure CaCO3 and can be used a limestone replacement to produce cement. They used to dredge coral sands off Fiji until about 10 years ago for this purpose but there were significant environmental issues. Coral can also be crushed for coarse aggregate and coral sand used for fine aggregate to produce a relatively weak, inferior concrete.

Reply to  Willis Eschenbach
January 30, 2017 11:46 am

Griff, do you ever get tired of being wrong?
The study didn’t overturn Darwin’s model, it supplemented it. Darwin’s model had been questioned since 1910 (Daly, 1910). The recent paper (which you didn’t even have the courtesy to cite) resolves many of the conflicts between Darwin and Daly and provides a model for coral formation and reef growth that could not be explained by Darwin’s model alone at islands that Darwin did not study (Toomey et al, 2013; )
“”Darwin actually got it mostly right, which is pretty amazing,” said Taylor Perron, the study’s co-author and a geologist at MIT. However, there’s one part Darwin missed. “He didn’t know about these glacially induced sea-level cycles,” Perron told OurAmazingPlanet.”

Reply to  Willis Eschenbach
January 30, 2017 6:15 pm

Ciguatera. The other whitemeat. Its the main reason people don’t eat parrotfish or other reef fish in tropical waters.

Reply to  Charles Rotter
January 30, 2017 5:50 am

The Liberal. Propaganda machine (called higher education in some circles) has done a marvelous job of eleminating training on topics/ knowledge that disagrees with their ideology.

Gary Pearse
Reply to  Charles Rotter
January 30, 2017 7:36 am

I was very disappointed when they changed the venerable, historic, readily understandable name of Geology Departments to mealy “Earth Sciences”. But with the latter having been co-opted by merchants of fear, I’m happy to have this buffer between real science and post normal drivel. When the sinistral parade is over (seems close now) we can simply recover the Geology part and let the other drift away, maybe to the mythical plastic island in the Pacific.

Reply to  Charles Rotter
January 30, 2017 9:11 am

The evil twin of junk science is republishing old findings without acknowledging the original work. The evil step sister is citing one’s own publications without acknowledging the original work. The business of science at work?

John Robertson
Reply to  Charles Rotter
January 30, 2017 7:16 pm

Since then everything has become unprecedented.
Plantfood is now atmospheric pollution.
And water has an “insignificant” effect on the computer modelling of earths climate.
Next we will be informed that earth is not a water world…Oh wait thats what the IPCC maintains.

January 30, 2017 12:16 am

What these researchers have accomplished is really quite remarkable. We could all take a lesson.
CTM, above, notes that parrotfish have been known to be a vital part of the reef ecosystem since forever.
So what did they really accomplish?

The Scripps researchers examined the amount and composition of fish, coral, and urchin fossils in 3 to 5-meter (10 to 33-feet) long sediment cores from three reef sites offshore of Bocas del Toro, Panama
The core samples, extracted by the researchers using a portable coring system they operated underwater while scuba diving

They got a luxury, all expenses paid vacation to Bocas del Toro for the express purpose of scuba diving on a world-class reef.
I have to put in a proposal to collect reef cores from Barbados. We must check if the results obtained for the western Caribbean hold up for the eastern Caribbean. Follow up trips will be required to account for discrepancies, of course.
{OK, I admit it. Getting cores going back 3000 years is pretty good stuff.}

Reply to  TonyL
January 30, 2017 2:57 am

Apart from “world-class reef”, you nailed it. Here are some vacation photos:

Mick In The Hills
January 30, 2017 1:24 am

Speaking of observational coral reef research Willis, you’ll be amused to know that, according to our national broadcaster (the ABC), Australian coral reefs condition can soon be monitored by drone fly-overs. Starting with Ningaloo Reef off northern West Australia.
Just think of the insights into parrot fish habits a drone will capture.
(of course the 23 hours 59.5 seconds of the daily life of a parrot fish that the drones miss will have to be modelled after homogenization with existing observations of whale sharks daily habits)

January 30, 2017 3:43 am

Willis, Parrotfish may be excellent at creating sand for beaches and island maintenance, but how does it benefit the coral whose skeletons are being chewed and themselves digested? If parrotfish were vegetarian, why are their mouths adapted to get at coral, and why don’t you see the fish predominantly on reef flats where the broken and largely coral rubble becomes infested with boring algae and sponges?

Dodgy Geezer
January 30, 2017 3:44 am
January 30, 2017 4:02 am

Great post Willis. That Parrot Fish are of vital importance to coral reefs has been known a long time. The study you review seems derivative and unoriginal. Why was it even funded? Maybe some researcher wanted a tropical vacation. Protecting parrot fish, if I was an islander, would be a high priority. You’re correct: national bird indeed.

January 30, 2017 5:03 am

Although I’d heard of the parrot fish, I wasn’t sure which of the many species of fish one sees when one snorkels in the Caribbean, so I went to Google Images and found this:

Reply to  techgm
January 30, 2017 8:03 am

Looks like global warming is causing mutations.

Gary Pearse
January 30, 2017 7:48 am

In Dominican Republic, Parrot Fish are very much on the menu. I have to admit I’ve eaten a few and they are quite tasty.. Actually, they catch more of these fish than any other so I hope they are prolific reproducers. They slice partway through the flesh of he whole fish in a series of parallel slashes and deep fry them. They’ve probably been doing this for hundreds of years. There are a mix of sizes – many too large for one person of average fish eaters so I think they are abundant, indeed. I wouldn’t want to see them depleted.

Johann Wundersamer
January 30, 2017 8:15 am


Tom Schaefer
January 30, 2017 8:17 am

Don’t forget the less brilliantly colored trigger fish.

Duane Truitt
January 30, 2017 8:42 am

Pretty much everybody who dives professionally or recreationally in The Bahamas and the Caribbean islands knows this, that parrot fish have created most of the “sand” that we take for granted areas with large coral reef structures.
What is even more amazing is the sheer volume of this parrot-fish “poop” … in the Bahamas Bank, the humongous shallow-sea area that surrounds and fills in the sea areas between the islands of The Bahamas, it is estimated that the depth of coral “sand” resting on top of hard bottom ranges from hundreds to thousands of feet. Not only does this illustrate the effects of geologic time that totally dwarf the short term thinking of so many of today’s so-called “climate scientists”, but it also illustrates that our coral reefs are not a “thing” that requires precisely today’s, or from a couple decades ago, climatic conditions, but they have thrived throughout the entire interglacial warming period and likely predated the Pleistocene Epoch, existing for millions of years of relatively quiescent climate stasis.
Corals are, quite contrary to the warmists’ dire warnings, a highly adaptive species that has been through many cycles of drastic climate change, and yet still predominate in our tropical and subtropical seas.
And lastly, anyone who dives or snorkels on an active coral reef can vouch that the underwater cacophony of the parrot fishes’ munching in the reefs is literally quite loud.

Reply to  Duane Truitt
January 30, 2017 11:54 am

Duane Truitt
It has always amazed me how an intelligent scientist could look at something as large as these islands and atolls and not realize how long they have been there, how long it took to make them and how trivial the various perturbations caused my mankind are in relation to the readily observable facts.
Back in 2007/8? National Geographics had an beautiful article on the blue holes of the Bahamas. Complete with many beautiful pictures. Several of the graphics indicated that they could determine how old these features were by the size of the stalagmites/stalactites in these “holes” that grew when the ocean was not as deep. Others showed the periodicity of the growth of these stalagmites/stalactites, which clearly was of a cyclical nature. Then, in accordance with AGW Ideology, the article ended with the obligatory CAGW Warning words to the effect that “These beautiful features will disappear because of global warming!”.
I immediately canceled my subscription. No longer even read/look at it in the dentists office.

January 30, 2017 10:03 am

Nice post Willis. It is amazing how interconnected life can be.
Parrot fish may be able to lay claim to some white sand beaches, but the salmon gets a lot of credit for the temperate rain forests. Massive amounts of nutrients taken from the ocean and deposited hundreds of miles inland.
Hmmm…if salmon runs impact forest health and forests are critical in the water cycle…I wonder if anadromous fish runs are in the climate models?
If frost ain’t I am sure nothing biological is included.

John F. Hultquist
Reply to  Bud St.Rong
January 30, 2017 5:14 pm

To add to that: Opportunistic feeders will take Salmon from the streams and cart the carcass off to a secluded place. Thus, the nutrient’s journey back to the ocean is a circuitous one.

January 30, 2017 3:33 pm

I certainly believe that parrotfish should be a protected species, especially the larger, slower-growing/reproducing species. There are many other viable food fish as well as a growing aquaculture industry to offset parrotfish being taken off the menu.

January 30, 2017 7:00 pm

” and please don’t eat the parrotfish …”
Why not? Jamaican parrotfish recipes are delicious!
Is there some way my eating a parrotfish in a restaurant is going to destroy a reef?

half tide rock
January 30, 2017 9:06 pm

Hi WIllis! I will have to do penitence for the fish that fed us as we sailed around the world so many years ago. I have been similarly educated by Bob Stenick. I don’t know why the roll of the Parrotfish was a not self evident. For those who are now better educated and will eschew the firm white meat ….parrotfish make a great Poisson Cru….. Lime, cucumber, onion, tomato and coconut milk.
As a comment, any one in my opinion that decides to go spearfishing at night with a flashlight in tropical reef water is much braver than I am. On a dark sormy night in the Tuamotus ( Tiairo) I put a man over board strobe light on two May West life jackets on a dingy anchor so we could “see the edge of the island”. We tacked back and forth in the pitch black. The strobe allowed us to be close in to the island’s miserable refracted, nodal point lee. (No radar celestial and eyeball only) well about 2 am the whole kit just dissappeared. One gulp!

Mark - Helsinki
January 30, 2017 10:39 pm

Well said W.
Besides, it’s well established that algae gets out of control when there is a nutrient imbalance. That will happen regardless of the presence of parrotfish who probably love coral with algae butter on it. 🙂

Keith J
January 31, 2017 12:04 am

Willis, you might get more sympathy from the special snowflake crowd if you mention the prevalence of sequential hermaphroditism in parrot fish species 😉
Just a casual observation.

January 31, 2017 1:17 am

It’s worse than I thought… 😉
From Swedish climate alarmist Wikipedia:
“Most species feed on those plants that exist between the corals and destroy to certain extent the coral skeletons. Other species eat mostly algae. One exception is the green humphead parrotfish species that eat the living parts of the coral.”
Stoopid horrible dangerous fishy fishes, right?
From English Wikipedia:
“Most parrotfish are herbivores,[9] but some species eat a wide variety of microscopic reef organisms. Some species such as the green humphead parrotfish (Bolbometopon muricatum) include coral (polyps) in their diets.[6] Their feeding activity is important for the production and distribution of coral sands in the reef biome, and can prevent algal overgrowth of the reef structure. The teeth grow continuously, replacing material worn away by feeding.[9] Their pharyngeal teeth grind up the coral and coralline algae[13] the fish ingest during feeding. After they digest the edible portions from the rock, they excrete it as sand, helping to create small islands and the sandy beaches of the Caribbean. The green humphead parrotfish can produce 90 kg (200 lb) of sand each year.[14] Or, very averagely (as there are so many variables i.e. size/species/location/depth etc.), about 275 g per parrotfish per day. While feeding, parrotfish must be cognizant of predation by one of their main predators, the lemon shark.[15] On Caribbean coral reefs, parrotfish are important consumers of sponges.[16] An indirect effect of parrotfish grazing on sponges is the protection of reef-building corals that would otherwise be overgrown by fast-growing sponge species.[17][18]”
I just luurve them Interwebs, and how they enable curious people to compare and evaluate “facts”.
I also find mr Eschenbach’s writing a pleasure to read.

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