Looking for plankton in PIPA

Kate Madin, Writer, Woods Hole Oceanographic Institution
Today was blue water dive day. Larry, Greg, Craig, Sam (one of Nai’a’s divemasters) and I dove off Kanton Island to find animal plankton. Naia’s skiff driver, Koroi, took us into the ocean where the bottom is thousands of feet down, and tied the skiff to the dive float.

Greg acted as the safety diver and went in first, then Craig and Sam – but before I got in the water, Greg stuck his head up and said, “You might want to hold up a while.”

A sizeable (6 ft.) shark had appeared as soon as the first divers splashed in, and was acting aggressively, coming at Greg twice. He fended it off with the shark stick, and it seemed to leave. Larry went in, I waited another 10 minutes or so – it didn’t return, so in I went.

Tumbling out of the skiff backward with scuba gear on feels like being in the wash cycle. Bubbles are everywhere, and it’s hard to tell at first which way is up. Then I check my buoyancy, and descend. Blue closes over me and deepens as I work my way down, holding the “down line” –a line tied to the float on one end and weighted on the other. Thirty feet down the line is the triangle-shaped metal “trapeze.” The divers clip 30-foot tether lines from the trapeze to their vests (“buoyancy compensators,” or BCs), so no one can drift away. The only visual points of reference are the lines, other divers, and ascending bubbles that reveal which way is up.

This kind of diving is like shopping. You are often in a vertical position, just “standing” there looking around for choice items to select. You’ve got a shopping bag – a blue mesh bag containing plastic jars to hold your catch. Divers might also have a camera or a shark stick clipped on the BC. Bag and stick and camera and tether line dangle between your legs or float over your head and generally get in your way, so you have keep them arranged during the dive. You scan the blue, not knowing exactly what distance you are focused on, looking for mostly transparent animals such as jellyfish.

If you see something you want, you swim over near it, being careful not to catch it in your bubble stream. Then fumble for a jar in your bag, gently guide the jar around it and replace the lid. This sounds easier than it is in practice, because gelatinous plankton are slippery and insubstantial, and flow right out of your jar if you aren’t careful.

This was a good dive. We saw different plankton here than at Nikumaroro, and every diver collected animals, including three kinds of jellyfish – one a box jellyfish (or cubozoan) that we will work to identify tonight; several siphonophores (relatives of the man-o’-war); and a beautiful transparent swimming snail (called Corolla) that looks like a butterfly (see image on bottom right).

Kanton Lagoon

Kate Madin, Writer, Woods Hole Oceanographic Institution
We are steaming from island to island in the Phoenix Islands chain so the expedition researchers will be able to do the broadest survey of PIPA reefs possible in the very limited time we have here.

About 3 pm local time, we saw Kanton grow on the horizon and Tukabu and Greg stood in the bow, watching our approach. The sky is pale and towering clouds are everywhere, but no rain has fallen yet. The air is very humid, with a non-stop breeze.

Last night we left tiny McKean Island, 3 degrees 35 minutes 84 seconds S; 174 degrees 7 minutes 68 seconds W, and are now at Kanton Island, an atoll where coral grew around an island rim, eventually reaching the sea surface as the island subsided, leaving a ring. Kanton is the only inhabited island in the entire PIPA, with a village of 40 or so people who monitor the reserve. Kanton also has a school, which some of us will visit during our three days there.

Nai'a's crew lowered the skiffs, and the skiff drivers guided Nai'a in through the narrow opening and channel into Kanton's very large central lagoon, where they dropped the anchor. We have to clear customs here, but an eager group of divers splash into the lagoon channel for a look around, even before that happens.

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After the dive, I interviewed some of the coral scientists . The verdict? Disappointing at first, they said, with quite a bit of dead coral and rubble. This is the result of the massive bleaching that happened when water temperature in the equatorial Pacific rose several degrees in winter 2002, a powerful El Niño event that caused the first bleaching ever recorded in this region.

But on closer look, coral is recovering: small coral heads are growing on top of larger dead heads, new branches are forming, and there are still large aggregations of lovely fish here. Divers are going back in the water in early morning, and hope to witness a remarkable sight—the parrotfish may spawn, which Greg Stone says has happened here before—they tend to spawn on the new moon, and an outgoing tide from the lagoon.

And tomorrow, more blue-water diving for plankton!

An Island of Birds and Recovering Coral

Kate Madin, Writer, Woods Hole Oceanographic Institution
Overnight we steamed the 60 miles from Nikumaroro Island, to McKean, our second stop in the Phoenix Islands Protected Area (PIPA) survey. We aren’t staying a full day, and there won’t be time for a blue-water dive here.

“The last time we were here,” said expedition leader Greg Stone this morning, “there were lots of big, aggressive gray reef sharks.’

The scientists on this trip suited up (in wetsuits) anyway, and went out to dive on McKean Island’s reefs at 7:30 am.

Low, isolated, and treeless, McKean Island is home to bird colonies and abandoned structures that attest to its past as a guano-collection site in the 19th century. Now that PIPA exists, the boobies, terns, frigate birds and other birds who live here ‘own’ the island, protected by Kiribati. Even in this remote place, though, a large fishing boat wrecked, and there is some metal and plastic debris on the beach.

A landing party went ashore on McKean, clambering over slippery broken rocks. Tuake Teema, Director of Research for Kiribati’s Ministry of Fisheries, checked baiting stations that the government of Kiribati placed on McKean in the hope of killing the rats on the island – rats are non-native animals that cause great damage to bird colonies. They found no evidence of rats - a good sign for the birds.

So how are the corals doing?
The scientists aboard are surveying these islands to learn if corals living in little-disturbed reefs are more resilient than corals in areas of more human activity, and will recover faster after bleaching - - which occurs when the water is too warm and corals lose the internal algae, such as during an El Niño event. “We know there’s an El Niño coming,” said marine ecologist Stuart Sandin, referring to current forecasts for winter 2009-2010, “and we’re all worried about resilience.”

On September 14th, Les Kaufman had this to say about Nikumaroro Island’s reefs: “Today we worked the windward side of the Nikumororo, and this brought views of a rich buffet of busily regenerating reef corals, already with substantial (30% to 50%) living coral cover in many places.”

Dives at McKean Island revealed a little live coral, a lot of dead coral, and some new coral growing. Marine algae - possibly fertilized by the island’s guano - are growing over many areas where corals were, but reef fish are here, eating the algae and the few remaining corals. The question on everyone’s mind is: Is coral recovery beginning?

Our next stop, Kanton Island, a 24-hour steam away, will probably be a much richer coral environment -- stay tuned.

Want to read more on the Phoenix Islands Expedition?
» View the New England Aquarium blog

Phoenix Islands Return

Brian Skerry, National Geographic and New England Aquarium Explorer in Residence
After nearly six days of sailing we reached Nikumaroro Island around 10:00 AM today. The tiny spec of land turned into a deserted tropical island clustered with palm trees the closer we approached. I had planned to use the days in transit to unpack and assemble all of my photo equipment, but the rough seas didn’t allow for this. So, I spent the first several hours today doing this along with charging batteries and prepping my dive gear. I was able to get everything ready in time for a dive in the early afternoon.

I dove on the leeward side of Nikumaroro and from the moment I jumped in, two things were evident. First there seemed to be a lot of fish. Second, the corals here were in rough shape. As I mentioned in my previous post, coral scientist David Obura was here in 2005 and recorded substantial coral bleaching and dead corals due to warming sea temperatures. Our hope was that in the four years since, new coral growth had taken place, however we saw very little of this.

I ended up spending about three hours in the water today, making two dives and concentrated mostly on photographing fish. There were some huge schools of surgeonfish in the surf zone, where I often love to work. The crashing waves create backlighting that can make for a beautiful picture, provided you can hold your position and not get slammed into a rock or coral head!

Nikumaroro Islands is the place that many believe Amelia Earhart landed on her historic attempt of a round the world flight. So, while fish were foremost in my thoughts today, I must admit that somewhere in the back of my mind I secretly desired to swim over an underwater ridge to find the wreckage of a Lockheed Electra lying amongst the coral. Didn’t happen though. I did swim amongst the wreckage of a ship that grounded here, but no aircraft debris today.

Tomorrow I am planning an early morning dive on the windward side of the island where I hope the reef will have fared better from the stressing event of four years ago.

» See the New England Aquarium blog for more information

Counting Fish and Corals

Kate Madin, Writer, Woods Hole Oceanographic Institution
Today on the Phoenix Islands expedition, scientists continued counting fish and coral. They work the reef by laying down lines of rope for a specific distance, then systematically count the fish or corals they see along the line, making notes on clip-boards they carry with them underwater.

Scientists have returned to this place seven years after a period of widespread bleaching on this reef, in order to assess the health of the reefs now. They hope to see whether an undisturbed reef system is more resilient to bleaching - and recovers faster - than reefs affected by human activity.

A group of us went ashore, to visit the island, including Greg Stone and Rob Barrel, who had both been there several times, to look for signs of the presence of rats or cats on the island. Both animals were introduced by humans, aren’t part of the natural island ecosystem, and cause great damage, so it’s important to know how many might still be there. There are large numbers of birds, such as the tern in the photo, as well as large sand and coconut crabs on the island. Tukabu, Director of the Phoenix Islands Protected Area and Tuake, Director of Research for Fisheries for Kiribati, came ashore with the rest of the landing party, and officially welcomed us to the country of Kiribati.

Nikumaroro is a coral atoll – a ring-shaped circle of coral sand and vegetation surrounding a central lagoon that opens to the sea through a channel. Scientists found abundant fish in that channel, and have also seen numerous manta rays, and many of the group took pictures of these large, plankton-feeding creatures, this one from Jim Stringer

The open, deep water surrounding a coral reef is intimately connected to the reef ecosystem, and in PIPA, the deep water is protected also. But to protect an ecosystem you have to know what’s in it. No one knows yet what animal plankton live in the open ocean around the Phoenix Islands.

So Larry Madin led four divers in a full blue-water dive today, looking for small or transparent animals (called zooplankton) that live in the open water, not near shore. Divers observed the water from the surface to about 80 feet, and collected several jelly-like transparent animals to identify back on the boat.

Tonight we leave Nikumaroro to survey other islands in PIPA, so everyone has to stow their equipment for the transit. The islands that make up the Phoenix Islands are far apart, and it may take a day of steaming to get there.

It’s a long way to Nikumaroro

Kate Madin, Writer, Woods Hole Oceanographic Institution
The dive boat, Nai’a, made good time, and this morning (Sunday, Sept. 13) dawned with us almost at our goal, the Phoenix Islands Protected Area (PIPA) - - where scientists will survey the reefs for the first time since the PIPA was established. We have much calmer water than during the transit from Fiji, and a rainbow graced the horizon this morning.

The expedition’s divers are excited about today, and the first dive on the reefs. At 8:00am Phoenix Islands time (17 hours ahead of Eastern Daylight Time), divers began assembling their gear.

From deck we saw our first stop, Nikumaroro Island – 4° 30’ south x 172° 10’ west. The island is approximately 4 miles long and 1 mile wide, a long, oval coral atoll surrounding a large lagoon, as the aerial shot shows.

Nikmaroro has a history: Whaling ships may have visited here in the late 1800s. A large ship, the Norwich City, was wrecked here in 1918, the wreck still at the water line. The British called it Gardner Island and established a settlement here in the 1930s, later abandoning it for lack of fresh water. Many think that Amelia Earhart crashed here on her final flight, and the International Group for Historic Aircraft Recovery (TIGHAR) has launched a handful of trips here to look.

But our science party is here to identify and count coral and fish species, and to see how healthy the corals are in this location. In 2002, waters warmed so much that a large part of Nikumaroro corals bleached, and the science team wants to learn if there has been recovery in these seven years. Chief scientist David Obura will be looking for data loggers he placed here in 2005 to record water temperature.

* * * * * * * * * * * *

After three dives today the fish researchers are happy with the numbers and kinds of fish they identified. Randi Rotjan, and David Obura worked on the reef: Randi, who studies predation on corals, now has new photographic evidence of bite marks fish make on coral - - white scars on the otherwise colored surface. David found the data loggers, right where he left them - - an invaluable record of temperature conditions the corals have experienced over the last several years. And some areas of coral show “striking recovery” from bleaching, Les Kaufman said, with new corals growing. And Larry Madin dove in blue water, and noted many colonies of radiolarians (single celled protists that form small globular colonies.). Now that we’re here in PIPA, the scientific work has begun.

Safe Diving in PIPA

Kate Madin, Writer, Woods Hole Oceanographic Institution
The Nai’a continues on a straight course from Fiji to the Phoenix Islands, carrying scientists and photographers, to study the coral reefs and open water of the world’s largest marine protected area -- the Phoenix Islands Protected Area (PIPA). The high waves and rolling motion we have been experiencing for days have decreased, making this a good day to hold the second meeting of the entire group.

The first meeting, on the day we departed Fiji, was to discuss the science plan for the expedition. Today, the group heard about the multi-tiered safety plan for diving. Rob Barrel, owner of Nai’a, Greg Stone, Craig Cook reviewed safety procedures for reef divers, and Larry Madin reviewed the procedures for blue-water diving.

Divers--especially if they’re absorbed in marking off sections of reef, or counting fish -- could become separated from others, or come up after a working dive and not see the skiff that will pick them up. Craig Cook and Randi Rotjan, before the trip, assembled safety equipment and a diver safety plan that will work to ensure no diver is lost.

First, diving in buddy pairs is essential. Then there are three methods of letting the skiff driver know where a diver has come up : Everyone will have an inflatable “safety sausage” - - a brightly colored tube a diver can use to wave in the air and signal the skiff. Every dive group will carry short-wave radios that can reach the skiff even at considerable distance. Last, there is a beacon that sends a signal to a satellite, and back down to Maryland receiver, a Coast Guard Station in Hawai’i and thence to the Nai’a, using GPS coordinates to locate a diver. Cook, in the image, is demonstrating the folding antenna to be used for that signal.

Last but not least, Cook spoke about the recompression chamber, emphasizing that it’s very rare to get the bends, but that the only treatment is to be put back under elevated pressure. Most of the divers will be using a mixture of gases called Nitrox, which contains less nitrogen and more oxygen than air, enabling divers to stay down at reef depths longer, with less chance of suffering the bends.

Les Kaufman, professor at Boston University, who is along to study fish, said, about the safety meeting:

“It is at once sobering and reassuring that very extensive preparations have gone into the safety measures for this cruise. First up, we reviewed the normal Nai’a dive protocols. Then comes ‘not getting lost’. … Sharks were up next: billies (shark sticks - long wooden poles) for those who want them… In fact we are hoping for abundant sharks as this is a sign of ecosystem health, and though once abundant, the sharks at Phoenix Islands have not been troublesome to divers on the earlier expeditions. We’ve also got an evacuation plan out of Kanton if somebody must be medivac-ed. DAN (Diver Alert Network) central, which is aware of our activities, stands by in case this is needed.”

Needless to say, we all hope none of the equipment or procedures will be needed on this trip. All are aware of our distance from medical facilities, and will be as careful as possible, but the extra measures of insurance are good to have!