Wednesday, August 10, 2011

Pteropod Physiology

Hey! This is Amy reporting in on my part of the project. I am a postdoctoral scholar at WHOI and my expertise is pteropod physiology. My job is to explore the response of individual species of pteropods to carbon dioxide. The goal is to determine how pteropods from different regions react to different oceanic conditions and to predict how they will respond to the shifts in these environments brought on by global climate change.

Deployment of the Reeve net over the stern of the boat. From left to right: Katie Wurtzell, Nancy Copley, Alex Bergan, our resident science technician Rob , Leo Bercial, Amy Maas and our bosun Clindor. The bucket that Leo and I are bending over is the cod end where all the animals we captured are waiting to be examined. Photo: P. Wiebe

Last night we put a Reeve net into the water. This net has a big bucket attached to the end (called the cod end) which helps us to delicately collect plankton from the ocean. During the night time many zooplankton can be found in the surface waters, so we put the net down after sunset for about half an hour and came back with a bucket full of critters. Already, between test station 1 and 2, we have found 9 different species of shelled pteropod – giving us lots of species to work with!

Me (Amy) looking very serious as I set up my experiments. Photo: G. Lawson
After hand collecting the animals from the cod end I moved them into the lab. Here, I let them settle into their new home overnight, which also gives me a chance to get some sleep! Today I am going to put individual animals into sealed glass experimental chambers.
An individual Cavolinia longirostris (on the left) inside a glass respiration chamber. Photo: Katie Wurtzell
I will bubble the water in these chambers with gas to resemble either modern day or future atmospheric carbon dioxide conditions. Then it is another 12-24 hours of waiting before I measure the amount of oxygen they have used up.
Water from the experimental chambers is sucked out with a small syringe (left) to keep it from getting in contact with air then injected passed an oxygen electrode (right). Photo: Katie Wurtzell
This measurement will give me an idea of how “stressed” the pteropods are under the different gas conditions and is a first step in figuring out how vulnerable specific species might be to carbon dioxide. The next step will be to bring the animals, frozen in liquid nitrogen back to the lab at Woods Hole where I can use molecular tools to measure specific stress and coping responses.
Photo of Clio pyramidata under the microscope. This pteropod has pulled down into its aragonite shell, tucking its wings (left) safely away from poking scientists. Photo: A. Maas

1 comment:

  1. The Cavolinia species were my favorites when I was doing pteropod dissolution studies in the 1980s out of the University of South Florida. It's amazing how glass-clear the tests are when they haven't been affected by any dissolution processes.