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Coral Triangle

Expedition to Halmahera: Week Two

Follow Nature Conservancy scientists Alison Green and Rod Salm as they blog about their expedition to an unexplored heart of coral biodiversity in Southeast Asia! 

Saturday, April 19th: Renewed Optimism About Coral Reefs

Visiting a site like this morning's would recharge anyone's optimism about the survival of coral reefs.

Near Rau Island, the shallows and upper reef slope support a vibrant, colorful coral garden. Not a coral was broken and the reef community radiated with resilience. In this day and age of heavy exploitation and climate-change impacts, such a sight is increasingly uncommon and truly inspiring.

A moderate current washes between two islands and along the reef, flushing it with clear water and sweeping away all silt and other rubbish that might choke the corals. The site is truly resilient and has great potential for inclusion in a conservation area.

The site was moderately rich for fishes overall, but yielded some unusual species and the highest site count for our colleague Kent Carpenter in his focal depths. It was exceptional for corals. Emre Turak scored 222 shallow water coral species, a personal best for this seasoned surveyor of Indo-Pacific reefs, and will likely record another 50 more when the deeper water species are included.

Good news on the turtle front today. Asril Djunaidi landed on a turtle beach and found the tracks of hatchlings that made it successfully down the beach and into the sea. Villagers say leatherback turtles nest here.

The village team led by Imran Taeran has also turned up interesting information, including use of turtles. They have yet to find any traditional management in practice, but arrived in a village during a meeting to revive the adat, or traditional management system.

The crustacean species are mounting too. Ucu Yanuarbi has recorded 42 species so far, with many hermit crabs still to be indentified. Mark Erdmann has added 34 species of mantis shrimp, including three new records for this area for a total of 76 identified crustaceans, excluding the many hermit crabs. (Rod Salm) 

Sunday, April 20th: The Heart of the Heart of the Coral Triangle

We are now on day seven of the survey, and I’ve done about 20 dives. Halmahera is living up to its promise to be the “heart of the heart” of the Coral Triangle, with the number of species recorded climbing steeply.

The coral experts have already recorded 450 species, which is more than half of the corals in the world (56 percent) and 75 percent of all the corals ever recorded in the Coral Triangle!

The fish experts have also recorded almost 700 species (686 including two new species), which is 12 percent of the world’s total and 31 percent of the number ever recorded from the Coral Triangle. And we still have three weeks to go!

It is very exciting to see the numbers climb every day, particularly when they discover species that are new to science. It is a rare privilege to be able to dive in global center of marine diversity with these experts. Every day we wonder what they’ll find next. (Alison Green) 

Sunday, April 20th: Saving a Turtle

Today I bought a turtle!

Asril, our turtle expert from Halmahera, has been rescuing turtles he finds in the community, using his own money and money donated by the survey team. Yesterday he rescued a rare olive ridley turtle, which I helped him buy. He is a very passionate and committed conservationists and I wanted to help him.

The villagers catch the turtles when they come up to lay their eggs — sometimes before or after they lay their eggs. They often take both the female and the eggs. It’s is very sad to see. When Asril finds that villagers have caught turtles, he explains why the turtles are so important and tries to save them if he can. A true conservationist!

Today he found that the villagers had captured two olive ridley turtles, which are rare and threatened. One was already dead, but the other was still alive.

Asril managed to convince them to sell it to him, and he released it as far away from the village as he could. Unfortunately, because it was a female turtle, she will return to lay eggs on the beach again (once a month in the nesting season), and there is a chance she will be caught again.

But one thing is for sure: If Asril had not bought her, she would have been killed. So at least she has a chance to come back and lay her eggs again, ensuring that there will be another generation of turtles in Halmahera. I hope she makes it! (Alison Green) 

Sunday, April 20th: One of the Best Dives of My Life

When you are a marine biologist, everyone has an image of you diving on spectacular reefs in crystal clear water when the weather is absolutely perfect — another day in paradise. But while we do get our share of those days, there are also many days when the weather is bad, the sea is rough and the reefs are not in great shape.

I’ve done thousands of dives all over the world, but some dives stand out as the best ever — and this afternoon's was one of those dives.

Andreas and I are counting key fisheries species on this survey, including large species that are particularly vulnerable to overfishing — big wrasses, parrotfishes, sharks and groupers. While many of the reefs we have visited have great biodiversity, these big fishes are often missing.

But today we saw LOTS of these species — by far the most so far in Halmahera. Andreas is a very experienced fish counter from our Raja Ampat program, and is usually a quiet and reserved man. Today he was so excited that he came to the surface yahooing with excitement and yahooed all the way back to the boat!

What was so exciting? 30 big humphead parrotfishes, four napoleon wrasses (including an enormous one 1.4 meters long!), a black tip reef shark, four big groupers, barracuda and a turtle!

These are species that you just don’t see in many places anymore because of overfishing. And it wasn't just the fish — right at the end of the point was the biggest coral colony we have seen on this trip so far (a huge Pavona clavus colony, at least 18 meters across). The other day we were excited to finally see one humphead parrotfish, and today we saw 30!

So it was very exciting. We also think we may have discovered an area where these species may aggregate to spawn, so we recorded the position and hope this special place can be protected in future. (Alison Green) 

Monday, April 21st: Coral, Alive and Dead

It is hugely encouraging to find such vigorously growing, intact coral colonies covering 70-90 percent or more of the reef. Both the exposed and sheltered sites we visited today had beautiful but different coral gardens.

The exposed site had more robust colonies of varying shapes and sizes, with some table corals reaching nearly 3 meters across. The corals in the sheltered habitat were other worldly — large fragile colonies of pencil thin branching corals and huge tables. All of this indicates little disturbance to these sites and the enduring nature of the coral communities here.

However, there clearly was a major and widespread coral mortality 10 or more years ago, and many areas show the evidence — banks of old dead branching corals or the remains of large tables that are slowly being settled by new recruits.

Where conditions favor vigorous coral growth, the long dead corals are almost completely overgrown. We will focus on trying to determine the cause if at all possible, but it is likely either bleaching linked to the worldwide 1998 bleaching or a major crown-of-thorns starfish infestation. With each year that passes, identifying the cause of mortality with any confidence is compromised.

We are anchored this evening in rhe rich waters of a bay that is alive with anchovies. They are like silver spray in our lights around us. Its little wonder we saw a Brydes whale on our way into the bay. (Rod Salm) 

Tuesday, April 22nd: Coral Cover in a "Lord of the Rings" Seascape

We investigated coral reef environments deep in Kau Bay. The sheltered conditions here have enabled growth of boulder corals topped by castellations and spires that create a surreal seascape fitting of the "Lord of the Rings."

But cyanide fishers have been at work, leaving their telltale white patches in the stagshorn coral surrounding a hole dug to remove the stunned fish.

The corals are unevenly distributed in patches over large areas dominated by different species. The evenness of size among individual species suggests that they are the same age and have had pulses of new coral growth and growth at different times for the different species. (Rod Salm) 

Wednesday, April 23rd: Turtles, Crocodiles and Big Waves

We had quite an adventure today!

The land team got wind of an apparent major leatherback nesting beach. I'm passionate about sea turtles and have provided some training on nesting beach assessments, so I happily joined a small group who went to shore. We walked 15 kilometers to the site.

There we found the tracks of nesting olive Ridley turtles and further evidence that their eggs were collected by people. During the journey we waded across two estuaries, one that had a strong current flowing out to sea and… crocodiles. We hoped the crocs preferred fresher water areas and headed in. Luckily, we didn't see any.

When our boatman came to pick us up, he ventured in close to shore and got caught in a huge wave that tipped the boat over. We managed to right it in the surf and, with the help of some great swimmers from the nearby tiny village, swim it back out beyond the surf. Just as we cleared the danger zone, a single small dolphin surfaced close in front of the boat and then was gone. (Rod Salm) 

Thursday, April 24th: De-gassing in Buli Bay

This morning we sailed into Buli and said goodbye to Rod Salm and Kent Carpenter, who reluctantly left us this morning for home.

Two new researchers joined us: Joanne Wilson from Bali and Sterling Zumbrunn from Virginia, USA. Thank goodness the local airlines did not let us down! Flights into and out of this part of Indonesia can be a bit unreliable.

We spent the morning tied up to the wharf in Buli. It was a welcome morning off.

The survey has been very exciting, but it's tiring doing 3-4 dives a day. It was great to have some time out of the water to “de-gas” — let the nitrogen leave our system. Nitrogen accumulates while diving, and too much can lead to decompression sickness or “the bends.”

By afternoon we were back in the water. A few years ago, Buli Bay had one of the best reefs. But, mining activities have increased dramatically since then. As a result, there was a lot of silt in the water and many of the corals in the deeper areas were very stressed by the sediment. Fortunately, those in shallow water where there is more water movement were still okay.

After diving, we headed into town to a dinner with local dignitaries, including the mayor, the head of the Fisheries Department, the head of the Police Department and the military commander. The officials were interested and concerned about impacts in the bay and our recommendations for management. (Alison Green and Mark Erdmann) 

Friday, April 25th: Coral-Eating Starfish

Our first dive was on Woi Reef in the middle of Buli Bay. For the first time, we saw evidence of a serious outbreak of the coral-eating crown-of-thorns starfish.

This species is often present on reefs in low numbers, but sometimes there is a major outbreak, when thousands of starfish severely damage coral reefs. At Woi Reef we found extensive damage (dead corals covered by algae) and lots of crown-of-thorns.

In an outbreak, the starfish can produce billions of larvae. Enhanced nutrients in the water contribute to higher survival of starfish larvae, while overfishing of starfish predators can also promote their survival — a form of positive feedback.

The reason for these outbreaks is one of the most hotly debated issues in marine science. Most scientists believe outbreaks are caused by declining water quality and overfishing linked to human impacts. (Alison Green & Lyndon Devantier) 

Friday, April 25th: Nighttime Journey to A Turtle Nesting Beach

After a long day of surveying, I decided to visit Patagtaga Island in the evening to see nesting hawksbill and green turtles.

We left at 1 am sharp for Patagtaga, about 2.5 nautical miles away. The water was so calm. We saw a lot of phosphorescence (light) in the water, which we think comes from squids and big jellyfish.

Several anchovies jumped out of the water around the boat. However, when I interviewed fishermen they complained that their catches are low recently because there is so much mucous in the water. Corals expel mucous to defend themselves from sediments and heavy nutrients caused by mining operations.

When we arrived at Patagtaga Island we heard voices of people, all waiting for the turtles to lay eggs. One man said that turtle eggs are not a main delicacy to them and that more information and study about turtles is necessary. We explained the purpose of turtle conservation and hoped that this man would pass the information to other people in his community. (Asril Djunaidi) 

Saturday, April 26th: Tall Spires and 200-Year-Old Coral

Went for another dive in Buli Bay today, and found a reef that seems to have escaped the crown-of-thorns starfish outbreak. In the shallows there were many large table corals and good coral cover. These corals are among the preferred food for the starfish, so it was great to see them flourishing in the bay.

Andreas Muljadi and I also found a remarkable colony of Porites rus with spires three meters high! Emre Turak and Lyndon Devantier estimated that this coral colony is over two hundred years old.

Joanne Wilson also made an interesting discovery: She found eggs in some of the branching corals. This is exciting because very little is known about coral reproduction in Indonesia. Stay tuned for more on this in the next few days as Joanne investigates further. (Alison Green)

« Expedition HalmaheraFollow along on the rest of the expedition: Week Three »


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