Hawaii's Milletseed Butterflyfish (Chaetodon miliaris)

by B. N. Sullivan

Chaetodon miliaris
Here's another Butterflyfish from Hawaii. This one is called the Milletseed Butterflyfish (Chaetodon miliaris), although you also may see it identified in some picture books as the Lemon Butterflyfish. Which common name you prefer may depend on whether you focus on its lemony background color, or its vertical rows of black spots.  The scientist who named the species focused on the spots, which he thought resembled milletseeds, hence  the species name miliaris.

Like the Multiband Butterflyfish (Chaetodon multicinctus that we presented in the previous post, C. miliaris is a Hawaiian endemic species.  In fact, the two species are closely related, both belonging to the subgenus Exornator. Nevertheless, the behavior of the two species is different in several ways.

Most conspicuously, the Milletseed Butterflyfish lives in aggregations instead of in pairs, and they are not territorial. It is not uncommon to see whole mobs of these bright yellow fishies moving along the reef together, looking for food.  Now,  "mob" is hardly a scientific term, but it suits shoals of Milletseed Butterflyfish.  Unlike some other fishes that school and move along in an orderly way, almost in unison, the Milletseeds move along together in an almost rowdy fashion -- but  I must say, that is a wonderful sight to behold.

Milletseed Butterflyfish have a much more varied diet than C. multicinctus. Their preferred food is zooplankton, but they also will eat the eggs of other fishes -- especially those of fishes that deposit egg masses on rocks and other surfaces.  Milletseeds sometimes perform as cleaners of other fishes, too.

The Milletseed Butterflyfish occurs naturally only in Hawaii, but it is not rare in the islands.  In fact, C. miliaris is said to be the most common among the 24 species of the Butterflyfish family (Chaetodontidae)  found in the Hawaiian islands.  If you dive or snorkel in coral reef environments in Hawaii you are almost certain to encounter a 'mob' of these yellow beauties.

The Multiband Butterflyfish (Chaetodon multicinctus), a Hawaiian endemic fish

by B. N. Sullivan

Chaetodon multicinctus
We'd like to introduce our readers to the Multiband Butterflyfish (Chaetodon multicinctus). This species is endemic to Hawaii and Johnston Atoll, i.e., it isn't found naturally anywhere else in the world.

These fishies are rather small -- about 10 cm (4 in) in length -- and their natural diet consists solely of coral polyps, especially those corals in the Poritidae family. The fish in the photo on this page is about to feed on a head of Porites lobata, a common stony coral on Hawaiian reefs that seems to be a favorite food of C. multicinctus. They feed by pecking on the coral head, extracting individual polyps.

C. multicinctus is a plentiful species on most coral reefs in Hawaii, and they are seen frequently by divers.  They don't shoal. or school; instead they live as monogamous  pairs that remain together over long periods of time, perhaps for life.  In case you are wondering, no one knows for sure how long 'life' is, but one researcher we know who studied this species told us their natural lifespan may be in the neighborhood of 15 years (providing they don't get eaten!).

These guys are quite territorial. Observational studies of the species in its natural environment have shown that pairs establish territories of 50-100 square meters.  Once established in their territory, a pair will remain there together and defend it from potential competitors,  actively aggressing against intruders of the same species.   Some pairs have been observed maintaining the same territory for periods greater than four years.  It's possible that they stay in the same territory for a lifetime, but again, no one has systematically observed a given pair longer than four or five years.

Like virtually all species in the Butterflyfish (Chaetodontidae) family, C. multicinctus is diurnal.  That is, they are active throughout the daylight hours, and at night they hide in crevices in the reef to take their rest.

By the way, some fish identification books and cards identify C. muticinctus by its alternative common name, Pebbled Butterflyfish.  Presumably that name refers to the vertical rows of speckles on the fish.  We also have seen it referred to as the Brown-barred Butterflyfish.  We prefer the common name Multiband Butterflyfish, since it is a literal translation of the fish's species name multicinctus.  (Or, as we often advise, avoid the confusion of variable common names.  Just learn the scientific name and be done with it!)

Note: For readers who may be interested in territorial behaviors and intra-specific communication by C. multicinctus, we recommend you have a look at: Tricas, TC, et al. (2006). Acoustic communication in territorial butterflyfish: test of the sound production hypothesis.  Journal of Experimental Biology, 209 (24), 4994-5004.

Watching and being watched underwater

by B. N. Sullivan

Recreational divers are essentially underwater sightseers. Just like sightseers on land, they take in the scenery and observe 'the locals' going about their business. In this case, of course, the locals are the critters that inhabit the reef.

But make no mistake, this isn't a one-way activity. The critters watch us just as we watch them. We've mentioned this a few times in the past. Longtime readers of The Right Blue may recall the story of Brutus, the Great Barracuda, who seemed to be attracted to Jerry's black and yellow wetsuit.  Brutus took to following Jerry  around on the reef -- again and again and again!

At least we knew Brutus was there -- really, you couldn't miss him!  But sometimes creatures in the sea watch or even stalk divers while the diver is oblivious to their presence.  As an example, we once posted a photo of a sneaky shark approaching a diver from behind, while the diver -- engrossed in what he was photographing -- remained unaware of the shark.  Based on our own experiences, we think scenarios like that happen very often.

It's amazing how marine animals can seem to appear out of nowhere!  We remember many occasions when animals startled us by literally swimming right over our shoulders. The photo at right is one example of that.  I was photographing something -- I don't even remember what -- when this Gray Angelfish suddenly swooped into view from behind me.  I pressed the shutter button just in time to capture the fish, rather than whatever it was I intended to photograph!

Many animals in the sea are curious about divers.  Whales, dolphins, sharks, large jacks, eagle rays and turtles all have, on occasion, altered their course to approach us closely to look us over.  Some have paused to watch whatever it was we were doing.

Sometimes, the critters seem to be hoping we will facilitate their search for a meal.  Dig in the sand, or turn over a rock, and you are likely to attract any number of 'inspectors' watching to see if you have unearthed something they would like to eat.  Direct a beam of light onto a reef during a night dive, and you may draw the attention of nocturnal hunters.

Usually these kinds of encounters are amusing, although sometimes they can give the diver quite a start, especially at night.  We recall several instances when our hearts momentarily skipped a beat during night dives when large creatures we weren't expecting to see suddenly appeared at very close range -- like the huge Manta ray that hovered so closely above us that we could have reached up and tickled its big white belly; like the Great Barracuda that zoomed over my shoulder to snatch the little fish I was about to photograph; like the 'wolf pack' of five Gray Reef Sharks that swept past our backs so closely that we felt the turbulence, which caused us to whirl around and train our lights on them just in time to count them as they sped away down the reef.

There are several factors at work here. For one thing, a diver's visual field is reduced underwater, compared to what it would be on dry land.  Even in the clearest water, a diver cannot see ahead more than, say, 45 meters (about  150 ft.) at most, and more often, horizontal visibility underwater is considerably less.  Things near the limits of that visibility range appear as shadowy lumps rather than as well-defined objects (or critters!).

Another impediment is the diver's mask.  It's true that without the mask -- and the airspace between the glass plate and the diver's eyes -- everything would look like a blur.  But at the same time, the skirt of the mask tends to block the diver's peripheral vision -- not just side to side, but also above and below.

Finally, we don't usually hear an animal approaching us underwater. There are no sounds of footsteps, and while the exhaust bubbles from open circuit SCUBA make noise, most marine animals make no discernible sounds as they move about.

What to do?  When you are diving, we suggest that you periodically glance up, and down, and look over your shoulder to see who or what may be watching you.

French Angelfish (Pomacanthus paru)

What: French Angelfish (Pomacanthus paru), a species common to the Caribbean.

Where: I photographed this pretty fishy on a reef near the top of Bloody Bay Wall, Little Cayman island.

Dolphins -- the most intelligent animals in the sea

bottlenose dolphin
Bottlenose Dolphin  (photo courtesy of NASA)

by B. N. Sullivan

About 25 years ago, while I was a Psychology graduate student at the University of Hawaii, I made several visits to the Kewalo Basin Marine Mammal Laboratory (KBMML) in Honolulu.  Those visits were field trips, made in conjunction with an intensive seminar on cognition that I was enrolled in that semester. The main focus of that seminar was human cognition, but along the way we studied comparative animal cognition as well, and my classmates and I visited the KBMML to learn something about dolphin cognition.

What we saw was impressive. At that time, researchers at the lab were just beginning to elucidate the extent of dolphins' ability to comprehend and interpret "an artificial sign language, in which gestures are like words and sequences of gestures are like sentences."  Through a series of carefully constructed experiments, the researchers were able to show that dolphins' comprehension of this language went far beyond mere response to commands (such as you would give to a dog to sit, or roll over).

 The dolphins were taught to associate hand signs with a corresponding noun object -- e.g., a beach ball, a hula hoop, a surfboard -- and they learned signed verbs, such as fetch, take, and jump. Using these vocabulary items in combination, the dolphins could be instructed to "fetch ball' or "fetch hula hoop" -- and they would select the correct item from among several floating in their pool, and bring it to the trainer.

But it gets better!

Selecting the correct item and fetching it is one thing, but the dolphins also showed an instrumental understanding that went beyond mere association of a given signed word with a corresponding object or behavior. For one thing, they displayed some understanding of syntax. As the folks from the lab explain:
For example, the gestural sequence Surfboard Person Fetch means, "take the person to the surfboard," whereas the sequence Person Surfboard Fetch means the opposite, -"take the surfboard to the person." The grammar used is inverse in its construction, in the sense that the destination object is stated first, then the object to be operated on, and finally the type of operation. This inversion requires the dolphin to receive and process the entire sequence before it can reliably interpret the instruction and organize its response.
We also witnessed the dolphins' response -- or lack of response -- to commands that did not make sense. If the trainer signed to the dolphin to "put the beach ball in the hoop," the dolphin obliged. But if the trainer instructed the dolphin to "put the hoop in the beach ball" the dolphin would not respond (beyond giving the trainer a look that clearly implied, "What, are you nuts??").

The more time we spent observing these experiments, the more it became apparent that this was not a case of dolphins trained to do tricks. Rather, it became clear that the dolphins were comprehending, and reasoning, and evaluating situations. [You can read about that research here.]

Those experiences have stayed with me all these years, so it was not too surprising to read recent news articles about subsequent behavioral research with dolphins that concluded that these marine mammals, rather than chimpanzees,  could be the most intelligent creatures on Earth after humans.  [Physorg.com has a nice review of that research.]

Long ago, I came across this quotation, attributed to British writer Douglas Adams, author of The Hitchhiker's Guide to the Galaxy:
"Man has always assumed that he was more intelligent than dolphins because he had achieved so much -- the wheel, New York, wars, and so on -- while all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man -- for precisely the same reason."

Hawaii Marine Debris Action Plan: Much needed program is the first in the nation

by B. N. Sullivan

Marine debris
Yesterday was an important day in the world of ocean conservation, and particularly for Hawaii.   The U.S. National Oceanic and Atmospheric Administration (NOAA) officially rolled out its new Marine Debris Action Plan (MDAP) for Hawaii -- the first in the nation.  Implementation of the MDAP is intended to protect Hawaii's coastal communities and marine life from the thousands of pounds of marine debris that wash ashore each year, just like that in the photo at right. [Photo supplied by NOAA].

The new MDAP is described as "a comprehensive long-term plan to actively assess and remove plastics, derelict fishing gear, and other human sources of marine debris from coastal waters and coral reefs along the island chain."  The plan, which was developed as a cooperative effort among NOAA; federal, state and local government agencies; academic institutions; conservation organizations; private industry; and community groups, aims to provide a comprehensive framework for activities to reduce:
  • the current backlog of marine debris
  • the number of abandoned and derelict vessels
  • land-based debris in waterways, and
  • fishing gear and solid waste disposal at sea
According to NOAA: Numerous strategies and activities fall under each of these goal areas, many of them already underway by Hawaii’s marine debris partners. These include debris removal efforts, emergency response, prevention and outreach campaigns, as well as increasing research and technology development. Progress will be tracked and measured for each of these areas.

These efforts are very welcome, and we are so pleased that the Hawaii Marine Debris Action Plan is now formally implemented.  Marine debris is a global problem, of course, and we hope that the Hawaii MDAP will serve as a model for similar efforts elsewhere.

For more information about the new program: Hawaii Marine Debris Action Plan (HI-MDAP) - 2 page 'pdf' file

Also visit the NOAA Marine Debris Program on the Web for related information, photos, and videos.

[Photo Source]

NOTE: This article was included in the February 2010 Carnival of Aloha, a blog carnival with a Hawaii theme. Have a look: Preservation and Lots of Aloha Create an Interesting Carnival

Related posts on The Right Blue:

Soft corals on Woodhouse Reef

soft corals

by B. N. Sullivan

After posting the previous article about the container ship that ran aground on Woodhouse Reef in the Tiran Straits, I decided to search our image archive for photos I had taken at Woodhouse that might show the beauty of the reef prior to the recent accident.  In particular, I was looking for a 'reefscape' image, rather than a shot of an individual creature.  I came across the above image of assorted soft corals on slope of  the reef, photographed a number of years ago.  My notes did not specify the exact location on Woodhouse, so I can't say it is the spot where the ship damaged the reef.

While browsing through our underwater photos from the four  Tiran reefs, I noticed that most of the photos were from Jackson reef and Gordon reef, with fewer from Thomas reef and the fewest from Woodhouse.  How could that be?  A quick check of our dive logs confirmed that among the Tiran reefs, we have dived on Woodhouse least often.  I also noted that most of our dives at Woodhouse were done as one-way drift dives, riding the tidal current along a face of the reef slope.  That fact may account for the relatively small number of images from Woodhouse in our Red Sea photo archive.  During drift dives on tidal currents, there are fewer opportunities to pause to take photos.

Maybe we need to do a return trip to the Red Sea, just to take more photos on Woodhouse reef? (Sounds like a mission!)

Container ship damages Woodhouse Reef in the Tiran Straits

by B. N. Sullivan

Regular readers of The Right Blue surely must know by now that one of our favorite places in the world to dive is the Red Sea.  We lived and worked in the eastern Mediterranean region for many years, and during that time, we went to the Red Sea frequently for dive breaks.  When we had the time to do so, we would spend a week or more on a live-aboard dive safari boat.  More frequently, we stayed at Sharm el-Sheikh and used day-boat charters to dive the reefs of the southern Sinai peninsula and the Straits of Tiran.

During that period of time, we visited the area so frequently that we came to know the South Sinai and Tiran dive sites as well as we know our reefs back at home.  Those reefs are incredibly lush, teeming with life -- and very photogenic.  Some of my best underwater photos were shot in the northern Red Sea.  It's been a few years since our last visit there, but our fond memories of the area have not dimmed.

All of  those reefs happen to be situated in or near very busy commercial shipping lanes.  The Tiran Straits separate the Gulf of Aqaba from the rest of the Red Sea.  All ship traffic heading to or from the busy ports of Eilat, Israel, and Aqaba, Jordan must thread their way around the reefs as they pass through that narrow passage between the coasts of Egypt and Saudi Arabia.  This week we learned that Woodhouse Reef, one of the four spectacular reefs in the Straits of Tiran, was seriously damaged when a 40,000 ton container ship ran aground on it on December 31, 2009.  The news made our hearts ache.

Underwater cameraman Tom Osborn dived at Woodhouse a few days after the ship ran aground there and filmed the damage.  In an article about the accident on the British Web site Dive Magazine, Tom Osborn relates what he saw:
"All of the reef in the area of the collision has been destroyed. It resembles a chalk quarry with fresh white lumps of rock scattered everywhere.

"You can see underwater that large sections of the container's hull has been crushed and sliced open from the force of the impact. As the ship smashed into the reef, she damaged huge chunks of the reef plate near the surface.

"An area approximately 30m wide and 20m long has tumbled away in sections down the steep slope of Woodhouse Reef like an avalanche, destroying any living coral below to a depth of at least 45m. At 35m you can clearly see a large slab of reef plate that used to be near the surface."
Here is a sample of the video shot by Tom Osborn that shows some of the devastating damage to Woodhouse Reef:

If the video does not play or display properly above, click here to view it on YouTube.

The Right Blue: Perennial Favorites

by B. N. Sullivan

It's always interesting to study traffic reports for The Right Blue to see which articles and photos earn the most attention -- not just when we first post them, but over time.  There have been some we just knew would be winners, while other winners of the blog post popularity contest have been complete surprises.

fire coral
In the previous post we reviewed which articles published in 2009 were the most popular, based on number of visits to each.  We'd like to note, however, that the five most popular posts on The Right Blue during the past year were not posted during 2009; they were older articles, dating back as far as August of 2007 (just a month after The Right Blue was launched).

In addition to showcasing our underwater photos, we've always had the goal of sharing what we have learned about the ocean and its inhabitants with readers of The Right Blue.  Knowing that there is a lot of junk information out there on the Web, I admit I am more than a little bit obsessive about presenting factually correct information, especially when I write about marine life.  Some of our 'creature features' are time consuming to prepare, but the reward is that information-heavy articles on The Right Blue almost always end up on the first page of search engine results, and remain there.  It's a nice indicator that what we produce is of value, and also has staying power.

With that said, here are the five posts on The Right Blue that were viewed most often during 2009:
  1. Fire Coral: Look, but do not touch, posted in November of 2007
  2. The Cave Where Turtles Die , posted in June of 2008
  3. Bubble Coral Plus, posted in May of 2008
  4. Dotted Sea Slug from the Mediterranean, posted in October of 2008
  5. Why is the sea blue?, posted in August of 2007
About the photo: I photographed this colony of fire coral (Millepora dichotoma) in the Red Sea at a dive site called 'Jackfish Alley', near the southern tip of the Sinai peninsula.  This fire coral species is very common in the Red Sea.

The Right Blue: 2009 Review

by B. N. Sullivan

So, here we are at the beginning of a new year on the calendar, and a new decade as well.  We hope our readers had an enjoyable holiday season, and we wish you all a happy, healthy and prosperous 2010!    During our holiday break we took some time to review where we've been -- literally and figuratively.  For one thing, we reviewed what we produced here on The Right Blue over the past year.  We also took a good look at the 2009 traffic statistics for this blog.

Southern Stingray (Dasyatis americana)
Here are a few interesting nuggets we discovered.  In 2009, readers in 170 different countries visited The Right Blue. About 67% of our readers were in the United States.

Well over half of the traffic to The Right Blue came via search (mostly Google).  Thousands of people landed at The Right Blue after searching for information about fire coral -- the number one phrase among a total of more than 13,000 unique search terms.  Most of the other top search terms were the name of some creature -- sharks, sea turtles, nudibranchs, various fishes and corals. And then there were the innumerable versions of the question about why the sea is blue: "why is the sea blue"; "why does the sea look blue"; "what makes the sea blue"; "how come the sea is blue" -- and so on ad infinitum!

Search produces the most traffic to The Right Blue, but the number two source of 2009 traffic -- about 20% -- was StumbleUpon.com (and we thank the readers who liked a post enough to Stumble it!)  We also noted a substantial (and growing) amount of traffic from both Twitter and FBI Blogs. Considering we only joined FBI Blogs in May, and Twitter in June, we are both amazed and gratified to see that these associations have become so fruitful so quickly.  Big thanks to Damon Tucker, who runs FBI Blogs, for inviting us to become a part of this group of top-notch Big Island bloggers, and thanks as well to our fellow FBI bloggers for their support.  (Note: In case you may not know, 'FBI' stands for 'from Big Island' -- not that other federal FBI.)

Speaking of Twitter,  Jerry has been the official Twitterer for The Right Blue since June of 2009, and thanks to his efforts, @therightblue already has just shy of 4,000 followers.  Jerry tweets the titles and links to everything we post here on the blog, of course, but most of what he tweets is ocean news and interesting finds on the Web about the ocean, marine science, conservation, and related topics.

Among the articles we posted on The Right Blue in 2009, these five were the most popular, based on number of visits to each:
  1. Tiger Cowries: The largest cowries in Hawaii, posted in May.
  2. Conus striatus - a fish-eating cone shell, posted in April
  3. Stingrays: Dangerous or not?, posted in May
  4. Hawaiian Green Sea Turtles, posted in May
  5. The Octopus: Nature's ultimate shape shifter, posted in December
I should note that although the above were the five most popular items posted in 2009, they were not the five most popular articles overall.  That honor went to three articles from 2008, and two from 2007.  In the next post we'll tell you which articles on The Right Blue have attained the status of Perennial Favorites.

About the photo: The image on this page shows a Southern Stingray (Dasyatis americana), a species common to the Caribbean, and occasionally seen in the Bahamas and along the coasts of south Florida.  I photographed this one at Stingray City, a popular dive site in the Cayman Islands.