Notes from the Field

Notes from the Field Archive

MADAGASCAR 2005

For more than 150 years, Academy scientists have been working to discover and document biodiversity around the world. As global extinction and habitat destruction rates rise, this work is becoming increasingly important.

The Academy’s most recent scientific expedition was to Madagascar, an island nation located off the coast of eastern Africa. Because Madagascar has been isolated from other land masses for over 160 million years, it contains an extremely high number of endemic species – plants and animals that cannot be found anywhere else on Earth. Nearly 13,000 species of plants and vertebrate animals are found exclusively on Madagascar, including over 90 percent of the island’s reptiles, amphibians, and mammals. Tragically, less than 10 percent of Madagascar’s original habitat is still intact, and a number of its unique species are at risk. Forty-five animals that recently inhabited the island are now extinct, and nearly 200 others are threatened or endangered.

Since 1998, the Academy has been sending scientists to Madagascar to study the island’s plants and land-dwelling animals. Over the past nine years, Academy entomologists, botanists, and herpetologists have identified more than a thousand new species from the island. In October 2005, the Academy sent a team of scientists to the shores of Madagascar to study the island’s aquatic species for the first time. Read more about their work – and share in their adventures – in the field journal below.

Radama IslandsOctober 12, 2005
Arrival in the Field

Although Madagascar is best known for its unique and endangered land-dwelling life forms, the huge island nation is also edged by extensive coral reefs and rich aquatic habitats. Sadly, many of the reefs have suffered from heavy coral mining, but the Malagasy government is now taking steps to protect its aquatic resources. In 1997, they created the 840-square-mile Masoala National Park, which encompasses an extensive coral reef and whale breeding ground. Now, the government and the Wildlife Conservation Society are initiating surveys of several other coastal regions in order to establish resource management priorities and identify possible sites for marine reserves. A team of researchers from the California Academy of Sciences is helping to conduct the surveys. For the next two weeks, I will be working with three of my Academy colleagues – Shireen Fahey, Terry Gosliner, and Bob Van Syoc – to document Madagascar’s aquatic biodiversity.
 
Today, we arrived in Madagascar and boarded a boat to the Radama Islands, which lie just off the northwestern coast of the main island. Nosy Be, Madagascar’s largest resort island, is situated to our north. As a coral specialist, I am anxious to get into the water and start documenting the coral species that are present here. Our first dive will take place tomorrow.

- Gary Williams


new barnacleOctober 13, 2005
A Bizarre Barnacle

This morning, we sailed to a reef northwest of Nosy Kalakajoro in the Radama Islands to conduct our first dive. Throughout the dive, I was on the lookout for my favorite aquatic animals – barnacles. These small invertebrates can attach themselves to a wide variety of surfaces, including rocks, corals, crabs, and even whales. One of the most interesting barnacles I found today had attached itself to an oyster. A bright orange sponge, which was attached to the same oyster, had grown around the barnacle shell, nearly covering it completely. Only the small opening at the top of the barnacle’s volcano-shaped shell remained uncovered, permitting the animal to continue feeding. When I removed the top of the shell, I saw that the barnacle had built a series of tunnels that allowed the sponge to grow underneath it as well. Intrigued, I brought the specimen back up to the boat and examined it under a microscope. Based on what I saw, I’m fairly certain that it represents a new species – I’ll be able to confirm that once I get back to my lab at the Academy.

This unique relationship between a barnacle and a sponge has never been described before. However, scientists have documented barnacles that live as free-floating organisms within a sponge. By setting up house inside a sponge, these barnacles gain a habitat that is free from both predators and competitors. It seems that the species I found today may represent an early stage in the evolution of barnacles that utilize sponges as living spaces.

- Bob Van Syoc


new nudibranchOctober 14, 2005
New Nudibranch

 
This black, red, and yellow beauty is a new nudibranch species that I found during the first dive of the day. Nudibranchs, which are often called sea slugs, are highly toxic – their bright color patterns serve as warning signs, telling potential predators to stay away. The coloration of this nudibranch is completely different from anything I have ever seen before. When I spotted it during the dive, I immediately recognized it as a new species and secured it in a ziplock bag.

This afternoon, we returned to the same dive site to look for another representative of this new species. (Scientists prefer to base descriptions of new species on more than a single individual.) After an hour of unsuccessful searching, we finally turned back and headed for the boat.  Just before we started to surface, we spotted the characteristic color pattern for the second time. We will bring both specimens back to the Academy, where we’ll be able to conduct molecular studies and determine where this species fits in the tree of nudibranch evolution.

- Terry Gosliner


cyanobacterial growthsOctober 17, 2005
A Slimy Mystery

 
Over the past several days, our team has conducted dives at a number of different reefs around the Radama Islands, and we’ve encountered a number of new species. We have also encountered a phenomenon that none of us had ever observed before. In many areas, the corals – particularly the soft corals – are covered by blue-green algae. This slimy substance is more properly called cyanobacteria, since it is actually composed of photosynthetic bacteria, not true algae.

One of my colleagues in Japan, Dr. Asako Matsumoto, told me that she has occasionally seen cyanobacteria growing on hard corals in Tokyo Bay. She believes that fluctuating sea temperatures may be responsible for the appearance of slime on the corals. It’s likely that some corals could be physiologically weakened by temperature changes or other environmental conditions (such as pollution or sedimentation) and thus become more susceptible to bacterial growth. While more studies will need to be conducted before a specific cause can be pinpointed, it is clear that these reefs are suffering from environmental stress of some sort.

- Gary Williams


night diveOctober 21, 2005
Night Dive

 
Tonight, Gary, Bob, and I had our first opportunity to dive at night. Although it’s a bit daunting to explore an underwater habitat in the dark, it’s a great opportunity to find nocturnal species that stay out of sight during the day. Gary was on the lookout for a group of corals called sea pens, since many of these species only emerge from the sand at night. Bob and I were helping him look, while keeping an eye out for other notable creatures. Each time one of us found something of interest, we’d jiggle our flashlights around to get each other’s attention.

About half way through the dive, I spotted a group of four nudibranchs on the prowl for prey. They were members of a new species that I had identified for the first time earlier in the week. During the day dives, I had only found two individuals, both of which were hiding underneath pieces of coral rubble. I now had confirmation that they were nocturnal animals.

Once we surfaced, Bob handed me a plastic bag containing this beautiful blue and black nudibranch. The species, Chelidnura livida, has only been documented in the past from the Red Sea. Bob found the first example from Madagascar.

- Terry Gosliner