Get the background on Keith's expedition to Totoya Island, Fiji in his first photo post. Catch up on the latest events in the expedition on National Geographic's News Watch blog.

The dive gear has dried in the sun. The collections are packed away. It's time for my last entry before returning home.

In 15 days, 5 divers collected, cataloged, and photographed over 1000 species of invertebrates from the coastal waters of Nosy Be, Madagascar. Our main targets were echinoderms, mollusks and crustaceans, though we collected many interesting animals from other groups as well. Our suspicion is that we have species of sea stars, shrimp and sea cucumbers new to science, including the one in the photograph:



Despite intensive assessment of a relatively localized area--never venturing farther than a two-hour dinghy ride from the research station--we were still picking up new trip records on the last day of diving. Many of these were not just small critters but also large and conspicuous echinoderms. This suggests that we did not reach a point at which the addition of new species records was abating. How welcome and useful it would be therefore to return here for more research!

Just as the marine biodiversity did not disappoint in this rich corner of the Indian Ocean, we were equally fortunate in having consistently great weather and CNRO as our base of operation. We were treated superbly by all the staff, and were not wanting for much. They have an incredible knowledge about their living marine resources, and I am indebted to the kindness they showed us during our stay.

On to the publications! I leave you with these photos from our trip.


Francois enjoying a solo game of "Cat's Cradle" with cuvierian tubules.



It took lemurs to show Gustav that his real passion is vertebrates after all.



Tim and visitor to the wet lab.


Tanikely



Art caught in post-dive reflection: "And again, the echinoderm biologists pick a lousy dive site low in crustaceans ... "


Ever the urban trend-setter, Roberto sports the latest fashion in Nosy Be.


Giselle, on break from sakai preparation, in search of invertebrates.

Cruising along the muddy bottom we occasionally see isolated soft corals or sponges rising up from the benthos (bottom dwelling flora and fauna). In the absence of reef and rock, these animals provide the living space for many other smaller creatures. We sampled a hollow-stemmed gorgonian coral only eight inches tall that yielded over 100 individual crustaceans and represented at least seven species.

This is one of these gorgonians:

And this is a sampling of the crustaceans recovered from a single pink individual:

And what of the sea cucumbers from these deeper murky waters? We saw only two during our dive, but one was an encouraging find. It was Holothuria scabra, one of the two or three most heavily exploited and high-value species occurring in Madagascar (shown below). The typical price in Singapore for this species in 2003 was between US$40-56 USD/kilo dried, but it would not be unusual to get over $100/kilo in other markets.

Sea cucumbers have been heavily fished for centuries as part of a multi-million dollar food trade, with China as the principal center of consumption. Not surprisingly, many of the large sea cucumbers are rarer in Nosy Be than would be expected to occur naturally. Certainly this reflects how heavy they have been exploited, and unfortunately around the tropics this is the norm rather than the exception. The deeper murky waters where we found this animal are more inaccessible to fishermen, and the best hope for many of these highly sought after species may be their ability to thrive in habitats farthest from their reach.

I am taking a rare and short break from intensive ocean biodiversity sampling to write this entry. My base of operation is the National Oceanographic Research Center in Nosy Be, an island off the northwest coast of Madagascar. I am here with a team of marine scientists--Dutch, French, American, and Malagasy--who are engaged in an underwater assessment of coastal marine life in this part of the world. The project (BIOTAS) has the goal of characterizing the region's biodiversity (land and sea), and examining the natural processes that have led to the geographic distribution patterns among multiple groups of organisms in
the southwest Indian Ocean.

The above photo shows the center's lab space as you approach from the water. Inside this building is where our group works well into the night processing all the material collected during dives.

Among the researchers here are experts in fishes and invertebrates. I am part of the invertebrate team, and am studying the sea cucumber fauna together with Dr. Gustav Paulay and Francois Michonneau of the Florida Museum of Natural History. Sea cucumbers are echinoderms, a group of animals that includes starfish, sea urchins, brittle stars, and feather stars. There are "sea cukes" that indeed have the dimensions of a cucumber you might slice into a salad, though body length among this group of animals ranges from a few millimeters to over 9 feet, and some can weigh over 10 pounds. They are found from shallow shores to abyssal seas, and are probably the least well studied of all large and conspicuous marine animals. Roughly 1600 species are described, though many more remain to be discovered.

One fascinating characteristic of sea cucumbers is best seen under a microscope. Unlike starfish and sea urchins that construct large continuous skeletons observable on many a beach walk, sea cucumbers instead have thousands of tiny skeletal pieces or "ossicles" embedded mainly in their body wall. These ossicles take on ornate shapes as indicated by the descriptive names used for the various types: buttons, tables, rosettes, rods, etc.

During the first few days of our expedition, we have seen many synaptid sea cucumbers, such as the one photographed above (Synapta maculata). These long and slender cucumbers have a body wall about as thin as tissue paper, and a diameter about equal to that of a stick of pepperoni. Colors can vary from bright pinkish-orange to greenish brown with dark bands. We saw animals on this trip that were up to six feet long!

If you touch one, the point of contact adheres to your body like glue. This is not caused by any chemical adhesive, but the mechanical action of the animal's ossicles which are shaped like boat anchors. It is these anchors, occurring in the thousands along the surface of the body wall, that cause your hand or wetsuit to become stuck to the animal. (A quick flick of the hand will release you!)

This weekend a team of researchers are taking off for Nosy Be, Madagascar. The northwest corner of the island has been identified as a biodiversity hot spot for both terrestrial and coastal marine biodiversity. The area is home to high numbers of unique forms of life and is under high environmental threat.

I will be among the researchers accompanying Dr. Gustav Paulay of the Florida Museum of Natural History on this mission. I will work with Dr. Paulay to collect samples of sea cucumbers and other species for biodiversity characterization at the organismal and genetic scales. Our contribution is part of a larger land-sea biodiversity assessment of the southwest Indian Ocean, coordinated by two researchers at the University of Reunion.

The broader study (BIOTAS) is seeking to not only characterize biodiversity in this part of the world but also to examine the natural organisms. The study will lead to greater understanding of how evolutionary processes shape species assemblage in the region and between its islands, and help identify conservation priorities.

My day to day routine will consist of diving, collecting and documenting species. I will be updating this blog from a satellite phone during the course of the expedition, and I look forward to sharing my observations on the invertebrate species we find.