Tuesday, November 23, 2010

Danger! Science ahead!

Oh the things we do for science! In our pursuit of documenting biodiversity we often throw caution to the wind and end up a little worse for the wear. Getting bashed in the surf on a coral reef or getting mauled by thorny plants is all in a days work, and frankly helps us feel a little more like Indiana Jones and a little less like the nerds we are. I failed to get a picture of the really impressive bruise I received while diving, but I didn't miss the opportunity to photograph John's legs after he came down from the mountain.

Some of the equipment we use can also be cause for consternation. The battery for the underwater vacuum had a little melting issue. So we did what any normal person would do and went to the hardware store, busted out a soldering kit and set about to make the repairs to an 18 volt battery. Jenna and Gary undertook this project with great success as previous vacuum footage can attest.

Some of the animals are also unappreciative of our attention. After carving two very large, very parasitic snails out of this sea cucumber's body wall, he repaid me by unleashing a torrent of Cuverian tubercles. If you are unfortunate enough to get tangled in these sticky strings, you will be picking them off for days to come. You're welcome Bohadschia argus, I hope you enjoy your new snail-free existence.

And then there are the animals who mean you no harm, but can still get your heart pumping if you're lucky enough to swim with them and aren't too busy installing ARMS to notice their proximity.

While always mindful of safety, it's easy to get wrapped up in the excitement of discovery!

:) Mandy

Sunday, November 14, 2010

Will climb mountains for land snails

Our intrepid terrestrial malacologist, Collections Manager John Slapcinsky, recently returned from climbing the highest peak on Moorea- the mountain Tohiea.  

Much of the climb is near-vertical, but pays off in the form of an isolated patch of forest, largely protected from the invasive species that dominate the lowlands of this and most other tropical islands.  This area is high enough to be in the path of many clouds, so the vegetation is moist and can be considered "cloud forest".  

The view is spectacular, but so are the relict populations of snails that are now gone from much of the island below.  One family of land snails, the Partulidae, was believed to be extinct until small relict populations were located at locations similar to this one.  

In the late sixties an African landsnail Achatina fulica was introduced to the island.  This species was perceived as a threat to agribusiness, and a biological control entity was sought.  In order to control this species, as second snail, the predator Euglandina rosea, was imported from Florida.  Euglandina had a rapid and terrible impact on the snails of Moorea- and bypassed the Achatina.  The genus of native tree-snail, Partula, which was common, diverse, culturally important, and the subject of decades of population research was chased across the mountain side in a loosing battle.  The genus was declared extinct in the wild in 1988.

Our lab is happy to confirm reports that small populations of these snails still exist in the wild.  Though they may never be as common as they were, at least they are still around.


Vacuuming the Reef

For quite some time, our group has been experimenting with using Vacuum sampling to get small, cryptic parts of the fauna off of coral reef rubble.  The most recent, and successful, design is based on a sampler that Dr. Richard Pyle designed for his deep water work.

We've had some trouble gettting the required parts through airline security, as Gustav has experienced first hand...  but now it is all here and working!  In the video below, Jenna and Mandy demonstrate its set up and use.

The device, though strange looking,  has proven effective at getting at some spectacular animals that we have not previously collected using other methods, such as the snail below, a "witches' hat" from a family of snails that are parasitic on echinoderms (Eulimidae, Bacula morisyuichiroi).


Saturday, November 6, 2010

Lab Work

I know what you're thinking, "did you really go to a tropical paradise to toil in the hot sun and crystal water, and labor up idyllic forested slopes? Don't you ever take a break for some refreshing lab work, replete with the soothing glare of fluorescent lights, the gentle clink of scientific glassware, and the warm radiance of sterile surfaces?" Of course we do, except for sterile part. We're field biologists, the chemistry is upstairs.

I've already mentioned some of the work we do in the lab for processing specimens. First comes the sorting. Since this is year three of the project we really want to focus on getting things that are new and interesting, so people pick through the mass samples (sand sample, leaf litter, etc.) and pull out the animals, which are handed off to an expert to determine what qualifies . Usually one uses a microscope for this, but some larger stuff can be seen with the naked eye. Allow John to demonstrate.

Even an expert IDer needs help every once in a while. For this purpose we have photo field guides that we have compiled over the past two years, comprised of photos of specimens we have already collected. This also help ensure that we are collecting new animals, and not something we have collected many times in the past.

You can see one of the guides open next to Charlotte's microscope. That might be another one in her lap. The experts can also help by IDing animals in the guide whose identity has remained a mystery to us.

The specimens are also photographed, especially those that will be subsampled and will no longer be intact. We have several set-ups for this, including two microscope systems, but the basic system that we used for marine animals is a clear aquarium we built elevated off a black background.

After photography most of the animals are subsampled for DNA extraction. For this, a little snippet of tissue is placed in a 96 well plate which goes into the DNA-extracting-robot. Here, Jenna and Gary are about to start loading the plate in Jenna's hands (Jenna not pictured).

There's also a lot of data entry, as all the information that goes with each specimen (photo, subsample, location, identification, habitat, etc.) must be recorded for the Biocode database as well as for cataloging back at the museum. The lab work is not glamorous, but when we discover something new and exciting it often happens here. Please enjoy this reenactment.

Now that our numbers have swelled to 12, I'll try and keep up with the posting. Science waits for no one!

:) Mandy

Monday, November 1, 2010

Underwater collecting techniques

Each collecting trip we try and take advantage of our numbers by employing a diverse array of sampling techniques. Everyone has their favored technique, usually dictated by the type of animal they are interested in, and the method most likely to yield that animal. I've been doing a lot of rubble brushing which entails picking a suitable rock from the bottom and brushing off the underside into a net. When I get out of the water at the end I empty the net into a plastic bag with water and bring it back to the lab for sorting.

This is me getting a nice, small rock from the bottom. Since I was manning this operation solo, I had three things to hold: the rock, the brush, and the net. A quick calculation reveals that that my two hands are somewhat inadequate. When the water is shallower this doesn't present a problem as I can kneel or stand (for breathing) and prop the rock (for brushing). At this depth I have to bring the rock to the surface to maneuver it (you know, to breathe), but it's hard to stay afloat while brushing and holding a boulder.

Art is a pro with the yabby pump. This device uses suction to draw animals out of burrows. The plunger is pulled quickly and the contents are emptied into a sieve. The sand falls through and whatever animal that was inhabiting that burrow is left in the sieve. Pumping is more difficult in the water because you don't have a nice solid surface with ample gravity to brace against. In this picture Sea is manning the pump and Art is holding the sieve on the lookout for interesting animals.

Art's particular interest is the shrimp that make many of the burrows, but there are often many commensals that come up in the pump as well. Like this cool gastropod (snail) which we're calling the Starship Enterprise, but which some call Phenacolepas.

We've also been doing a lot of sand sieving in our quest for micromolluscs. Since John is one of the resident mollusc guys he's being doing a lot of the sieving. He swims along the bottom pushing the sieve and scraping off the first few centimeters of sand. Then he roots through the sieve to see what he's found. As with the brushing, the contents of the sieve will be emptied into a plastic bag at the end of the dive.

The duration of each sieve push is limited by depth and buoyancy, and once again, when snorkeling, deeper is harder.

We've also been getting a lot of rubble samples now that Charlotte is here with her penchant for polychaet worms. This entails hauling around bags of rocks and coral rubble which will be rooted through back at the lab.

In gathering rocks and rubble there's a lot of sticking of hands into nooks and crannies, but one must be vigilant.

Can you see the eel? It's a dangerous job, but we're just the team to undertake it!

:) Mandy