The Right Blue

Whale Tail at Dusk

2011-03-03T08:30:00.002-10:00

Last evening at dusk, we went sailing with some family members on Kawaihae Bay, on the Kohala Coast of Hawaii's Big Island. The winds were light, the ocean surface was calm, and the mood was peaceful.

We were escorted for awhile by several Humpback Whales. The whales seemed to be in a placid mood as well. We saw no breaches or other dramatic behaviors. Instead, the huge cetaceans glided along near the boat, occasionally diving below the surface for a time and then reappearing to blow and breathe. I snapped this photo of one whale's tail just as as it began a dive.

Hawaii's Big Island to Host Ocean Film Festival

2010-12-29T16:00:00.004-10:00

Coming very soon to the Big Island of Hawaii: The Waimea Ocean Film Festival!

The festival, which will take place from January 6, 2011 through January 9, 2011 promises "four and a half days of film, presentations, exhibits, jumping whales, and turqouise water" to attendees.

Venues include the town of Waimea on the Big Island, and the Fairmont Orchid and Mauna Kea resorts. A smaller, more intimate version of the festival will show again at Four Seasons Resort Hualalai January 13-15, 2011.

TICKET INFORMATION – Film, Event, Contributors and Hualalai passes for the festival may be purchased by calling 808-960-9744 or via email by contacting info@waimeaoceanfilm.org

According to the festival's organizers:

The film festival will feature screenings of 30-40 documentary films and exclusive footage by local Hawaiian flimmakers. The festival includes inspiring paddling footage and surfing films, important and thought provoking documentaries, stunning nature films, and films about island history and culture. A few of the films to be shown include Melali, 180˙ South, Waverider, Sun Come Up, I Am, The Watermen Experience, Papa Mau, Bag It! and Ocean Voyageurs.

The festival will also host presentations by experts and industry leaders, such as Tom Shadyac, director of Ace Ventura Pet Detactive and the Nutty Professor, to speak on the making of his first documentary film, I Am, and Flip Nicklin, photographer and author reknown for his work on humpback whales. Filmmakers will be on hand for Q&A sessions after many of the films.

Attendees also can participate in many other activities, such as yoga on the beach, outrigger canoe paddling lessons, and breakfast talks by filmmakers and other speakers.

There will be art exhibits, including a work in progress by artist Aurora Robson made from plastic debris collected on Kamilo Beach as part of a volunteer clean-up and an exhibit of photography by the National Geographic photographer who traveled with the Hokulea to Tahiti in 1976.

Also: Na Kalai Waa, the Hawaiian voyaging society on Big Island, will host sunset picnic talks each evening, with one evening on the ancient art of Wayfinding, and one evening with a traditional hula telling the story about the sail of Makali’I to Tahiti.

And, as a grand finale, participants can enjoy a lua'u feast at Mauna Kea Beach Hotel, on one of Hawaii’s most beautiful beaches.

Click here to view the Waimea Ocean Film Festival brochure.

"Humpbacks from Fire to Ice" - Photo provided by the Waimea Ocean Film Festival

Hymn to the Sea

2010-06-13T13:45:00.001-10:00

If the video does not play or display properly above, click here to view it on YouTube.
Hat tip to Tony Berkman at FriedEggs.com, which is where I first saw this video.

Who's sleeping on the job around here?

2010-05-16T13:55:00.001-10:00

by B. N. Sullivan

I know, I know -- it's been awfully quiet here at The Right Blue for the past couple of weeks. If there were crickets underwater, you'd probably hear them chirping!

I haven't been sleeping on the job. I've been traveling, and then catching up on stuff related to my day job, so I've neglected this space. I'm about ready to get busy here again -- posting new photos, creature features, and articles about the marine environment. -- so please stand by.

Meanwhile, if you haven't already done so, do check out Jerry's very active Twitter stream @therightblue. He's been busy there, keeping our followers informed about developments surrounding the horrendous oil well catastrophe in the Gulf of Mexico, among other ocean-related topics.

Earth Day Greetings from the Blue Marble

2010-04-21T21:30:00.003-10:00

by B. N. Sullivan

April 22, 2010 is the 40th anniversary of Earth Day, and to celebrate, we decided to post our favorite image of Earth -- the 'Blue Marble'. This now-famous photograph was taken on December 7, 1972 by the astronauts of Apollo 17, which was the last manned mission to the moon. The photograph, listed in the Apollo 17 Image Library as AS17-148-22727, is described this way:

A Full Earth from the Apollo 17 Command Module at about 5 hours 6 minutes, shortly after separation of the docked CSM-LM from the S-IVB at 4 hours 45 minutes. Note that the trajectory is far enough south that Antarctica is visible.

That simple description belies the stunning impact of this iconic image. If anything can remind us of the interconnectedness -- the oneness -- of the Earth's seas, land masses, and atmosphere, the evocative imagery of the Blue Marble is it!

This Earth Day, regardless of what else you do, we encourage each of you to pause and reflect on the Blue Marble. That's our home -- the only one we'll ever know. Each of us individually, and all of us together, must do whatever we can to look after it.

Purple sea slug (Hypselodoris apolegma)

2010-04-15T06:20:00.003-10:00

by B. N. Sullivan

Isn't this a pretty little critter? It is Hypselodoris apolegma, a nudibranch from the family Chromodorididae. It doesn't have a standard common name, so we just call it the purple sea slug. This attractive nudibranch lives in the western tropical Pacific region.

H. apolegma feeds on sponges. It seems to prefer a dysideid sponge of the genus Euryspongia, but it may feed on other sponges as well.

Like many nudibranchs, the purple sea slug lays its eggs in a ribbon-like mass. The egg mass of H. apolegma is yellow.

The creature's striking coloration makes it an attractive subject for underwater macro photography. I photographed this one off the northern coast of the Indonesia island of Sulawesi, in the Celebes Sea. This specimen was about 3 cm long (about an inch).

The species fact sheet for H. apolegma on the Australian Museum's authoritative Sea Slug Forum describes this creature's coloring as follows:

The background colour is a rich pinkish purple with a white border to the mantle. At the edge of the mantle the border is solid white but inside this is a region of varying width in which the white forms a reticulate pattern gradually merging in to the pinkish purple. The rhinophore stalks and the base of the gills is an intense purple, the rhinophore clubs and the gills are orange yellow.

Yep, that's our purple sea slug!

Visit the Hypselodoris apolegma species page on the Sea Slug Forum for more information and photos, including feeding records, mating, and the egg mass of this species.

Chinese freighter accident threatens Australia's Great Barrier Reef

2010-04-05T22:40:00.091-10:00

by B. N. Sullivan

A Chinese ship, the Shen Neng 1, has run aground off the coast of Queensland, Australia. The accident happened this past Saturday, April 3, 2010.

The site of the accident is Douglas Shoal, which is about 70 kilometers from Great Keppel Island, in a restricted area near the Great Barrier Reef. The ship had left the Australian port of Gladstone a few hours before the late afternoon accident, and reportedly was off course -- outside authoriszd shipping lanes -- when it ran hard aground on the reef at full speed.

News reports say that the ship, a 230 meter long bulk carrier, was hauling a cargo of at least 65,000 tons of coal, and had around 1,000 tons of heavy fuel oil on board at the time of the accident. The vessel's 23 crew members are still on board, and are said to be safe, but fuel oil is leaking from the crippled vessel and is threatening the ecosystem of the Great Barrier Reef. Worse still, the vessel is said to be in danger of breaking up. If that happens, both its cargo and the rest of its fuel would be released into the sea with potentially devastating effects.

A New York Times article about the accident quoted an Australian maritime safety official who said that a hole in the bottom of the ship had allowed water into the main engine room. Both the main engine and the ship's rudder have been seriously damaged, complicating efforts by salvage teams to find a way to remove the Shen Neg 1 from the reef.

Aircraft have been dropping chemical dispersant onto the fuel spill, but rough seas have prevented deployment of floating booms that could contain the spill.

Here is a video that covers the main points of the story so far:

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

Seeing stars in the Mediterranean Sea

2010-04-01T23:30:00.002-10:00

by B. N. Sullivan

If you go diving or snorkeling in coastal areas of the Mediterranean region, you are very likely to see this Red Sea Star (Echinaster sepositus), which is the most common starfish species in that area. Divers and snorkelers have a good chance to spot this sea star resting on the bottom along rocky coastlines. Although there are records of Mediterranean Red Sea Stars found at depths of more than 200 meters, they are seen most often in relatively shallow water -- less than 10 meters.

Mediterranean Red Sea Stars are actually red-orange in color, rather than pure red. As sea stars go, they are relatively large. The one in the top photo on this page was about 20 cm (8 in) in diameter. The individual in the photos below was even larger -- nearly 30 cm (12 in) across.

Like many common sea star species, Echinaster sepositus has five rays, or arms. One time, however, we found a six-armed sea star that looked just like E. sepositus, except that it had an extra arm. At first I was not certain that it was indeed the same species, so I took the time to photograph it carefully. Someone who knows much more than we do about Echinoderms looked at the photos and assured us that the six-armed sea star was a less common, though well-known, morphological variant of E. sepositus.

The two macro photos below are of the unusual six-armed Mediterranean Red Sea Star. In these macro photos you can see the characteristic surface of the sea star, which is uneven -- sort of dimpled. In the first of the two photos below, you can see the tiny structures, called papullae, which protrude from the 'dimple' indentations on the sea star's surface. In the second photo below you can see the animal's tube feet protruding from grooves on the underside of each ray.

Both the tube feet and the papullae facilitate water exchange, and are involved in the animal's respiration and excretion. The sea star 'breathes' by extracting oxygen from sea water. It excretes some dissolved waste matter through the papullae and tube feet, too.

The tube feet also aid the sea star in locomotion. The tube feet in each row move successively, in a wave, using hydraulic pressure from the animal's water vascular system. This allows the critter to crawl along. By a similar process, the tube feet also can be used to pass bits of food from the distal ends of the rays to the sea star's mouth, which is at the center of its underside.

If you look closely at the second macro photo below, you can see that there is a little suction cup at the tip of each tube foot. These structures help the animal stay put after it situates itself on a rock or other hard surface. If a sea star gets overturned, it can right itself by twisting one or more of its rays so that the tube feet can grab hold of the surface and turn itself right-side up again. (This process can take quite awhile and consumes a lot of the critter's energy, so if you pick up a sea star to look at it, be kind enough to return it to its normal position!)

The sea star lounging in an algae bed in the photo at the top of this page was photographed in the shallows of Aedipsos Bay, on the coast of the Greek island of Evia. The two macro images below, of the six-armed Mediterranean Red Sea Star, were photographed at Cape Greco, Cyprus.

Caribbean Brown Tube Sponge (Agelas conifera)

2010-03-26T08:10:00.001-10:00

by B. N. Sullivan

This Brown Tube Sponge (Agelas conifera) is a fairly common sight on walls and reef canyons in the Caribbean region, and the Bahamas. The tubes, which reach a length of 30 to 90 cm (about one to three feet), grow in clusters from a common base.

This sponge likes deep water, so you are not likely to see it on shallow reefs. It prefers depths below 10 meters (30 ft), and we have seen the species at depths greater than 30 meters (100 ft), especially at places like Bloody Bay Wall, Little Cayman Island. That's where I photographed the example above.

Row Pore Rope Sponge (Aplysina cauliformis)

2010-03-24T13:55:00.002-10:00

by B. N. Sullivan

The Row Pore Rope Sponge (Aplysina cauliformis) is a Caribbean species. Its common name describes it well. It grows ropy-looking branches, and its excurrent openings ('pores') are arranged in long rows along the lengths of the branches. The ropy branches can grow quite long -- to a maximum of 180 to 240 cm (about six to eight feet ). The longest branch of the one in the photo above was about 150 cm long (about five feet). This sponge comes in several pretty colors: purple, lavender, and red.

This sponge is fairly common throughout the Caribbean, and may also be seen in the Bahamas. It usually inhabits deep reef slopes and walls, at depths below 12 meters (40 ft) . I photographed the one above at a dive site called Garden Eel Wall on Cayman Brac, Cayman Islands.

Video: Underwater junkyard off the California coast

2010-03-19T13:55:00.000-10:00

by B. N. Sullivan

We've posted several articles about a nasty ocean environmental issue: marine debris. Since this is one of our pet peeves, we have repeatedly reminded divers and beachgoers to deposit their trash in proper receptacles or to take it home with them. Moreover, we have asked them to pick up and properly dispose of debris they find on the beach and in the water, including abandoned nets and fishing tackle, even if they did not put it there to begin with.

Being mindful about trash such as picnic remains and general litter can help to reduce damage to reefs, the pollution of waterways, and the risk of entanglement by marine wildlife -- and that's a good thing. But a much more serious and pervasive problem exists as well: using the ocean as a dump!

Have a look at this Fox News video, and you'll see what we mean:

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

Thanks to @scubadivergirls and Deep Sea News for alerting us about this video.

The Ornate Butterflyfish (Chaetodon ornatissimus)

2010-03-15T16:25:00.000-10:00

by B. N. Sullivan

Fishes in the Butterflyfish family (Chaetodontidae) are among the prettiest inhabitants of tropical reefs around the world. This species, the Ornate Butterflyfish (Chaetodon ornatissimus) is particularly nice looking, we think.

The Ornate Butterflyfish is easy to recognize, with six diagonal yellow-orange stripes on each side of its creamy body, black and yellow bars on the face (including one that covers the eye), a gray patch on its forehead, and black 'trim' around its margins. They are said to grow to a length of 20 cm (about eight inches), although most of the adult individuals we have seen are somewhat smaller -- usually about 15 cm (six inches).

C. ornatissimus feeds exclusively on live coral polyps, so you would expect to find them in coral-rich areas. They seem to favor coral polyps of the Pocillopora and Montipora genera. (Here in Hawaii, we frequently see them pecking on Pocillopora meandrina.)

Juveniles of this species look like cute miniatures of the adults. The juveniles can be quite shy, hiding in corals for protection. The juveniles live as singletons, but once they reach breeding age, they find mates and form pairs. In fact, it is unusual to see an adult of this species not accompanied by its mate. Also, pairs establish a home range, so once you discover a pair of C. ornatissimus, you will likely be able to find them again in the same area time after time.

'Ornates' are an Indo-Pacific species, most commonly found in the central and western Pacific, from Hawaii to Australia's Great Barrier Reef. Sightings have been reported as well around Christmas Island in the eastern Indian Ocean, and we have seen photos of the species taken in Indonesian and Malaysian waters. They are quite common here in Hawaii. I photographed the one pictured on this page in Honaunau Bay, on the south Kona coast of Hawaii's Big Island.

Don't feed the critters

2010-03-12T15:15:00.004-10:00

by B. N. Sullivan

There are some dive sites where you know immediately that the fishes and other critters are used to being fed by divers and snorkelers. How can you tell? You can hold out your hand, like Jerry is doing in the photo above, and see if the fishes come forward. Sometimes you don't even need to extend your hand. At some sites, the fishes begin to converge on divers as soon as they descend from a boat.

So, is feeding the critters a bad thing or an okay thing to do? Generally speaking, we advise against it.

For one thing, it can be disruptive to the critters in a number of ways. Feeding an animal something that it would not naturally eat can disrupt its digestion and nutritional status. Even if you choose to feed something the animal might normally eat, you alter its natural feeding behavior by supplying the food item.

For another thing, feeding critters encourages them to congregate in places where they might not normally stay -- like at the base of a boat mooring. While the critters may learn that if they hang out in a particular place, they will be fed, their predators also learn this. You may be setting up the unsuspecting recipient of your offerings for becoming a meal himself!

And then there's the diver safety issue. If you've ever been mobbed by a swarm of fishes expecting a handout, you know what I mean. We have been followed around on many occasions by fishes that had become accustomed to being fed -- including eels and stingrays. As annoying as being mobbed by Snappers or Butterflyfishes may be, it can be worse -- even dangerous -- if the hungry critters are large and/or toothsome and aggressively pursue divers expecting a treat.

Long-time readers of The Right Blue may recall a story we told awhile back about a particularly aggressive Napoleon Wrasse in the Red Sea. The huge fish was accustomed to being fed boiled eggs. The wrasse apparently mistook the white second stage of our friend's regulator for an egg, and chomped it hard enough to detach it from the hose.

We know a dive guide who used to feed a certain large Moray eel, and then pet it. One day he reached out to pet the eel and it snapped at him, clamping down on his finger. At the hospital emergency room the doc said the only reason the dive guide did not lose that finger was because he was wearing a heavy class ring, which probably deflected the eel bite just enough to save the digit (although it was pretty badly mangled).

Remember, folks. The creatures you see in the ocean are wild animals, not pets. Don't give them indigestion and don't mess with the natural food chain. Don't feed them.

About the photo: I took this photo of Jerry (and a handful of Yellowtail Snappers) at the wreck of the Oro Verde, located off Grand Cayman's Seven Mile Beach.

Whale Shark excitement on the Kona Coast

2010-03-04T10:05:00.003-10:00

by B. N. Sullivan

In late February we posted an article about Whale Sharks (Rhincodon typus), with a video to illustrate. That video was shot at Christmas Island in the Indian Ocean. We now direct your attention to another Whale Shark video, shot a year ago on the Kona coast of Hawaii.

YouTube user dolphinmind, who posted this video of some very happy snorkelers' encounter with the Whale Shark, said:

A great day of Kona Coast snorkeling on Hula Kai turned unforgettable by an extremely rare 40 foot long whale shark encounter... Folks...no special effects or editing on this video...it's REAL. ...

Yep, and it's REAL BIG!

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

So, there was this tsunami in Hawaii...

2010-02-28T16:55:00.007-10:00

by B. N. Sullivan

Here in Hawaii, the drama began on Friday evening, Feb. 26, 2010, while I was watching the Olympics on television. As is usually the case when I watch TV in the evening, my mini netbook was on my lap, and I was playing a game on it. In addition to the game, I had Twitter open in my browser -- not wanting to miss anything that might be happening somewhere in the world. (I admit it: I'm a breaking news junkie!)

At exactly 8:36 PM Hawaii time, I saw the first mention on Twitter of a huge earthquake off the coast of Chile. The first report said the magnitude was estimated to be 8.3. A few minutes later, that estimate was changed to 8.5, and a tsunami warning was issued for Chile and Peru. Roughly an hour after that, the magnitude of the quake was upped to 8.8, and it was announced that a tsunami had indeed been generated.

That was it for me. I had no further interest in my game, the Olympics, or anything else on TV, save for the news. I watched the story develop on TV and on the Web until about 3 AM, when I could stay awake no longer. But by that time I knew that a tsunami was headed across the Pacific; that an official tsunami warning had been issued for Hawaii; that coastal evacuations would begin at 6 AM; and that the tsunami was projected to reach Hilo minutes after 11AM on Feb. 27. Believing (correctly, it turned out) that most of my family members and friends on the Big Island already were asleep when the tsunami warning was initiated, I sent tweets and emails to them to give them a heads up about what we all would face when morning came.

Promptly at 6 AM -- right on schedule -- the civil defense sirens along the coast began to wail their warning to those who lived in inundation zones to prepare to evacuate. The sirens warbled again, each hour on the hour, until 10 AM when roads along the coast, as well as those that led into and out of the inundation zones were closed. Coastal evacuees traveled inland and upslope; vessels left the harbors and went far out to sea to wait in open water; some small craft were trailered inland for the duration.

We sat tight at our house, not needing to evacuate since we live on a hill at an elevation about 500 feet above sea level. At 10:30 AM the final warning siren sounded. I have to admit, it was a bit nerve-wracking.

We watched live coverage of the scene at Hilo Bay. Everyone was nervous. After all, the epicenter of the present quake was very near that of another great quake in 1960, which generated a tsunami that wiped out much of downtown Hilo and claimed 61 lives. In addition, people of our era have seen vivid images of the Boxing Day Tsunami that followed a huge earthquake off the coast of Sumatra on Dec. 26, 2004, which swept across the Indian Ocean, killing hundreds of thousands of people. All of this was on our minds, but no one knew exactly what to expect.

The predicted time of arrival for the tsunami came and went. The webcam trained on Hilo Bay showed calm water, under a clear blue sky. Several minutes later, however, the water began to flow out of the harbor into the bay. As the water receded, the surface roiled, there were ribbons of foam, and the color of the water changed radically from transparent blue to a very muddy, opaque brown. Rocks and reeftops that had been submerged were now bared for a moment. Then the water surged back toward the shore.

This cycle was repeated at least six or seven times over the next hour and a half or so, and indeed, officials have said that smaller, less noticeable (to casual observers) surges continued for many hours. When the tsunami warning was lifted, just before 2 PM, evacuees were allowed to return to their homes and businesses along the coast, but the beach parks remained closed. Everyone was warned not to venture into the ocean, due to the possibility of unpredictable and potentially strong currents.

In Hilo Bay, the largest surge turned out to be just over one meter high. There was no breaking wave, but the surge did wash over the breakwater, and briefly covered a dock in the harbor. Although we did not witness it, we heard reports that the tsunami swelled into the mouths of the two rivers that empty into Hilo Bay, surging upstream and turning the river waters very muddy. As the mass of sea water pushed into the rivers, it uprooted vegetation along the river banks, and carried it back out to sea, along with rocks and other debris from the river bottoms. Fortunately, though, the surge was insufficient to cause it to overflow the bay and the harbor to an extent that caused damage. Hilo was spared, and so were all the other coasts of the Hawaiian Islands.

We don't have tsunami alerts very often, and the number of times a tsunami has reached our shores is relatively small. Still, there have been several instances in which a tsunami large enough to do damage did come ashore in Hawaii, did cause destruction, and did cause injury and loss of life. Island residents take tsunami alerts very seriously.

We have warning sirens on all of our coasts, and people know that when the sirens sound, they should immediately head inland and/or upslope and ask questions later! Indeed, during yesterday's event, there were no reports of people who did not cooperate with the evacuation order.

For more information about the tsunami hazard in Hawaii, visit the Pacific Disaster Center's Tsunami page. For tsunami alerts and data, visit the Web site of the Pacific Tsunami Warning Center, where you can also sign up for email alerts or subscribe to an RSS feed that will bring you alerts in real time.

Whale Sharks: The biggest fishes in the ocean

2010-02-26T12:15:00.003-10:00

by B. N. Sullivan

There are lots of fishes in the sea, but there are none bigger than the Whale Shark (Rhincodon typus). These huge sharks live in tropical waters around the globe, and we have had encounters with them in many locations. Seeing these magnificent animals always is a thrill. Their size -- up to about 40 feet (12 meters) in length -- is impressive, and their grace is almost magical.

Unlike most sharks, Whale Sharks are filter feeders. They feed on krill, algae, plankton, and other small organisms suspended in the water. They take in large gulps of sea water, and sieve out the food as it passes over the denticles that cover their pharynx and gill plates. The water is expelled through the gills, while the filtered-out food remains and is swallowed.

No one knows for sure how long Whale Sharks live, but estimates of the creatures' natural lifespan range from 70 to about 100 years. Whale Sharks do not reach sexual maturity until they are about 30 years old. They are ovoviparous: that is, their eggs hatch inside the mother, develop without a placenta, and then emerge as live young.

Whale Sharks are curious and often approach divers and snorkelers to have a look, and will sometimes swim alongside them, but these sharks are not known to be aggressive. Encounters with these enormous but docile creatures are a joy for divers.

Here is a video, shot at Christmas Island in the Indian Ocean, that perfectly illustrates the excitement of divers who encounter Whale Sharks in the open water:

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

If you are interested to learn more about Whale Sharks, we recommend you have a look at this Whale Shark (Rhincodon typus) Issues Paper, from the Australian Dept. of the Environment, Water, Heeritage and the Arts; and the Whale Shark page on the National Geographic Web site.

Staghorn coral (Acropora cervicornis), a threatened species

2010-02-20T13:25:00.006-10:00

by B. N. Sullivan

When we think of endangered or threatened species in the ocean, we usually think of sea turtles, or whales, or certain kinds of fishes. Unfortunately, populations of some coral species also have been seriously depleted, and some are at risk for extinction.

According to the language of the Endangered Species Act of 1973 (ESA), a species is considered to be 'endangered' if it is in danger of extinction throughout all or a significant portion of its range. A species is considered 'threatened' if it is likely to become an endangered species within the foreseeable future.

The pretty Staghorn coral (Acropora cervicornis) in the center of the photo above is officially classified as a 'threatened' species. Acroporid corals like this one are important reef-building corals, and they provide a habitat for fishes and invertebrates..

In the United States, this species is found in the Florida Keys, and along the Atlantic coast of Florida as far north as Boca Raton, but it is absent from U.S. waters in the Gulf of Mexico, according to the National Oceanic and Atmospheric Administration (NOAA). A. cervicornis does occur in the western Gulf of Mexico, and also in the Bahamas, the Caribbean islands, and Venezuela.

In a few places (very few) it is still possible to see large stands of this antler-shaped coral, but more often these days, the species exists only as small colonies, like the one in the photo above. In fact, reef surveys have shown that, since 1980, populations of A. cervicornis have collapsed, declining by up to 98% throughout the range.

So, what is responsible for such a marked decline? The number one threat to Acroporid corals is White-band Disease, a devastating, rapidly spreading disease that destroys the tissues of the coral. The cause of White-band Disease is poorly understood, but the results are devastating.

A. cervicornis is "particularly susceptible to damage from sedimentation and is sensitive to temperature and salinity variation," according to NOAA. In addition, NOAA lists hurricanes, increased predation, bleaching, algae overgrowth, and human impacts among the factors that threaten Acroporid corals.

Fortunately, conservation efforts have been initiated to manage and protect what remains of the A. cervicornis population. In some areas -- such the U.S. Virgin Islands, Puerto Rico, and the Florida Keys National Marine Sanctuary (FKNMS) -- restoration activities also have been undertaken following hurricanes, ship groundings, and the like. Nevertheless, restoration efforts, such as re-attachment of broken coral fragments and attempts to culture and settle coral larvae, are painstaking and have had limited success.

What you can do:

When you snorkel, dive, or go to the beach, NEVER stand on or touch coral.
Do not collect coral, dead or alive. (Federal and State regulations prohibit collection of all soft and hard corals.)
Divers should maintain proper buoyancy, be careful not to kick corals when swimming over them, and keep gear items such as hoses, gauges, etc. secured so that they do not drag across the coral.
Boaters should use mooring buoys wherever they are available. If you must anchor, avoid doing so near coral; instead of throwing your anchor, swim it down and place it on sand.

The above rules apply to all corals, of course, not just Acroporid corals.

More information: NOAA Fact Sheet: Atlantic Acropora corals - 2-page 'pdf' file

Mushroom corals: Solitary corals of the Fungiidae family

2010-02-15T07:35:00.093-10:00

by B. N. Sullivan

Do the images on this page remind you of mushrooms? The corals pictured here belong to the Fungiidae family. Note that the family name has the same word root as the English word 'fungus', and these corals are known by the common name Mushroom Corals.

Although the appearance of these corals may look similar to the underside of a mushroom cap, the resemblance stops there. These are stony corals; they are not soft.

While most hard coral species live as colonies of polyps that aggregate and form calcareous structures, most species of corals in the Fungiidae family live as solitary corals rather than as colonies. In addition to being solitary, most of the corals in this family are free-living -- that is, they are not attached to the substrate.

The photos on this page show two examples of solitary, free-living corals from the Fungiidae family. Both of these are Indo-Pacific species, widely distributed across the region from the Red Sea in the west, to the islands of the central Pacific. Both of the corals shown here were photographed in Hawaii.

The image near the top of this page is Fungia scutaria, the most common mushroom coral in Hawaiian waters. F. scutaria also is the largest of the mushroom corals found in Hawaii. It typically grows into an oblong or oval shape that can reach a size of about seven inches (18 cm) in length, although most of the individuals we have seen are about half that size.

The second photo shows Cycloseris vaughani, a smaller mushroom coral species. Cycloseris corals are more circular or discoid in shape. Adults of this species grow to a diameter of about two inches (5 cm).

Both of these species begin the post-larval stage of their lives attached to the substrate by a stem-like structure. As the juveniles mature and take on their adult form, the stem gradually dissolves, and they become free-living adults.

Mushroom corals usually are found in sandy areas near the base of stands of reef-building corals, and on rubble slopes at the outer edges of fringing reefs. They are found less frequently in shallow areas where they would be subject to being tumbled about by waves and surge. They prefer more sheltered environments.

Mushroom corals are known to feed on plankton and the metabolic by-products of the symbiotic algae that live in their tissues, but a team of Israeli scientists carrying out a reef survey in the Gulf of Aqaba (Red Sea) recently witnessed mushroom corals feeding on -- of all things -- rather large jellyfish! They documented the species Fungia scruposa feeding on a Moon Jelly (Aurelia aurita). You can read about this amazing discovery in this article (with photos) published by the BBC: Predatory coral eats jellyfish.

See also: Alamaru, A, et al. (2009). Opportunistic feeding by the fungiid coral Fungia scruposa on the moon jellyfish Aurelia aurita. Coral Reefs. DOI: 10.1007/s00338-009-0507-7

Video: Turtle-watching at Puako, Hawaii

2010-02-10T19:20:00.031-10:00

by B. N. Sullivan

I'm traveling on the U.S. mainland right now. A change of scene can be a good thing, but I do miss the ocean when I'm away from the islands.

This evening I logged on to Twitter to catch up with news from here and there, and what do you suppose I discovered? Someone I follow on Twitter just happens to be vacationing right now in Puako, Hawaii. Looks like we have temporarily traded places. Small world...

Judging by her tweets, Michelle and her family are enjoying their time on the Big Island. Here is some evidence: a video of Hawaiian Green sea turtles (Chelonia mydas) lazily pottering about in the shallows at Puako, shot by Michelle's son.

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

Related: Our page about Hawaiian Green sea turtles, and our page with links to all of our stories, photos, and videos of several sea turtles species.

Sharing Aloha: Hawaii in the spotlight

2010-02-03T07:35:00.004-10:00

by B. N. Sullivan

Our blogger friend Evelyn over at Homespun Honolulu regularly hosts the Carnival of Aloha -- a blog carnival celebrating all things Hawaiian. The theme of the current edition is Preservation and a lot of Aloha, and it is well worth reading.

Topics in the current Carnival of Aloha are diverse, ranging from a thoughtful (and thought-provoking) piece about a visit to an ancient Hawaiian heiau on the Big Island, to reminiscences about a romantic visit to the island of Lanai, to an item about the pineapple fields on Maui. There are several articles about Hawaiian real estate, including one on the current residential market, another on the foreclosure of Hawaii Raceway Park on Oahu, and an article that describes the home in Kailua used by President Obama's family for their vacations in Hawaii -- with photos of the home's stunning interior and grounds. (Don't miss that one!)

And yes, our article about the new Hawaii Marine Debris Action Plan is included, too.

We think there is much in the current Carnival of Aloha that will be of interest to readers of The Right Blue, so we invite you to visit: Preservation and Lots of Aloha Create an Interesting Carnival

One more thing -- speaking of interesting blogs about Hawaii. We spotted a story about an encounter with dolphins in the wild that we know readers of The Right Blue will enjoy and relate to. It's a guest post by Lisa Weber on Pua and Keoki's Best Hawaii Vacation blog: Kayaking with Dolphins, On Their Terms - A Big Island of Hawaii Story

Same or different?

2010-02-01T06:00:00.001-10:00

by B. N. Sullivan

This image reminds me of those puzzles: Which one is not like the others?

At first glance, all the fishes in the photo look alike. They're similarly shaped, their bodies are white with lines, and they all have yellow fins and black trim, including a black bar over the eye. But if you look more carefully you will notice that there actually are two species of Butterflyfishes swimming together.

The two fishes in the foreground of the photo -- the ones with the black spots near the trailing edge of their dorsal fins and the diagonal lines on their bodies -- are Threadfin Butterflyfish (Chaetodon auriga).

The larger fish in the upper part of the photo is a Lined Butterflyfish (Chaetodon lineolatus). Note that it has a broad black arc on its back, instead of a spot, and the lines on its body are vertical rather than diagonal. (And yes, that's another Lined Butterflyfish behind the two Threadfins.)

Both of these are Indo-Pacific species, and they are widely distributed. We have seen them -- usually in pairs -- in many locations from the Red Sea all the way to Hawaii. The ones here were photographed in Honaunau Bay, Hawaii.

Earlier we posted close-up images of each of these species. If you take a look at those earlier photos of the Threadfin Butterflyfish and the Lined Butterflyfish, you will be better able to appreciate the differences in their markings.

So, if you see a pretty Butterflyfish -- white, with lines on its body, and with yellow and black trim -- now you know which details to look for that will distinguish the Threadfin Butterflyfish from the Lined Butterflyfish.

Hawaii's Milletseed Butterflyfish (Chaetodon miliaris)

2010-01-30T16:40:00.005-10:00

by B. N. Sullivan

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

2010-01-28T15:40:00.003-10:00

by B. N. Sullivan

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

2010-01-23T20:40:00.003-10:00

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)

2010-01-20T09:50:00.001-10:00

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.