- Written by Julie Schram
Right now, I want to give you a sneak peak into how we are going about creating a controlled system where we can precisely control the temperature and pH to find some answers to our climate change questions. As you may imagine, this quickly becomes complicated because we are trying precisely control physical variables (temperature and pH) that tend to change quickly with changing conditions in a rather harsh environment.
In order to maintain control of our colder target water temperatures (1.5oC or 3.5oC), we will be performing our experiments out in the Palmer aquarium room, where the room temperature has been around 4oC for the past week. Since we arrived here at Palmer Station, we have been working long hours out in the aquarium, getting everything set up for the experiment. Many of those hours have been quite chilly, especially when you have your hands in the water for even short amounts of time.
Setting up the experiment has included all of the things that Kevin, Maggie, Chuck and Kate have already discussed, including but not limited to collecting and subsequent sorting of amphipods and algae, PAM readings, and water chemistry parameterization. That means a lot of work and plentiful multitasking days for all of us. Today, I would like to focus a little more on the physical set up of our experiment.
It’s hard to imagine now, but only a few weeks ago, these were just two sets of bare shelves. Each year we have built up everything that we will need to perform our OA/temperature experiments on these shelves. That is the nature of performing research at a field station, you have a limited amount of space available to you and it is shared throughout the year with a wide variety of other researchers doing a wide variety of experiments. At the beginning of the season we build it all up and right before we leave, we pack it all away again.
To control the temperature of our experimental treatments we are using large water baths to circulate water of a pre-set temperature. As you can see in the picture, those big grey water baths are hooked up to plexi-glass water tables that hold our experimental microcosms (the containers that hold our experimental organisms) and keep the temperature stable.
In addition to controlling the temperature, we are also controlling the pH by bubbling a CO2-air mixture directly into each of our microcosm containers (hence all of the tubing and pH-probes). We have a programmed computer system that monitors the pH of each of our experimental pH microcosms and changes the amount of CO2-air mixture delivered to each container based on information provided by the pH probes.
Kate and I spent most of the day today monkeying around with the experimental set-up, adjusting everything to ensure that the computer programming is doing what we want it to do. We have been tweaking this set up since we arrived. This process includes ensuring that the water chemistry (by testing the seawater pH and total alkalinity) in each microcosm is being maintained at our target levels. In addition to all of this we are also doing checks of the lighting, temperature, and going over the whole set up to make sure nothing is leaking.
Each of these steps can be very tedious and time-consuming. We are fortunate to have a field team with such a wide background of knowledge and experience. It has allowed us greater flexibility in putting all of the many experiment pieces together to get this experiment off the ground, so to speak. If any one of us had to do this all on our own, it would take at least 6 months to accomplish what we have gotten done in under a month.
Hopefully after this brief introduction of our experimental set-up, you will have a better idea of the context in which we are working once we get everything up and running soon. We are in the final stages of checking everything and making sure that we have everything we need to start this experiment. I am excited to see everything coming together.
- Written by Maggie Amsler
What brings the “Dark Continent” to my mind in this “White Continent” you ask? Well it is all the time I have been spending with giraffes and gazelles of course. Huh, you say?? Ok, giraffes first.
You probably know giraffes are tall, long legged creatures that feed on leaves in the upper branches of acacia trees. Their stretch allows them to access yummies not within reach of shorter fellow plant-eaters or in biospeak herbivores. How exclusive! So too one of the amphipods our project focuses on has the ability to utilize an alga that is out of reach to most but not because of height but because of nasty chemicals in the alga that render it unappealing to most other herbivores. The amphipod, Paradexamine fissicauda however, eats that red alga, Plocamium cartilagineum, like it is candy! Imaged left is this amphipod, we call it for short Paradex on its snack food the red alga P. cartilagineum.
So why do I equate Paradex with a giraffe? Paradex is painted with red/white splotchy coloration. Its exoskeleton/skin has a lot of spiny, spiky projections. The combination of those two features lend a perfect camouflage for Paradex as it wraps itself amongst the fingered branches of its favored red alga P. cartilaginuem. On many of the recent dives we have collected pillow-sized mounds of the red alga to sort through and hunt out the Paradex for use in the ocean acidification experiment that will be part of Julie’s work.
Julie calculated she needed a total of 720 Paradex for her experiment so I have been on safari through Plocamium for days and days now. But why do I equate Pardex to giraffes other than it being a somewhat exclusive herbivore? It is because just like in Africa, I could watch a giraffe and then suddenly, before my eyes it would disappear - it simply vanished into the savanna woodland without sound, without movement!
Paradex displays similar giraffe magic and can just seamlessly merge out view - if in contact with Plocamium. Its camouflage color and spiny features are a perfect combination for simply dissolving into its favorite alga. To collect them though I just need to tease apart fronds of Plocamium suspended above water and the Paradex will drop like rain into the watery oasis. Very cool! I am happily relieved to report I have now isolated over 800 Paradex for Julie’s experiment. But - she needs another amphipod species – the gazelle mentioned above of course.
So, when not looking for a needle in a Plocamium haystack for Paradex, I have been stalking similarly diver collected brown algae in pursuit of (keeping with the African analogy) of a swift and agile gazelle. A Thomson gazelle actually in my cold sorting hands reverie but in reality, the amphipod Gondogenia antarctica- Gondo for short. Sleek and sharp–eyed with short segmented antennae alternating in shades of orange and red –in my imagination mimicking the short horns ringed at intervals of the Thomson’s gazelle - Gondo, is a commonly used amphipod for feeding studies in our lab. It is very abundant on the local large brown algae. It is smaller than Paradex though so Julie determined she would need twice as many as Paradex or just over 1400!
Unlike Paradex, Gondo does not sit still and will bolt from its preferred brown alga host with the slightest disturbance. But we biologists are as crafty as the lion and fast as the cheetah with a special pipet to slurp up the intended zig zagging Gondo and transfer it to a meshed cage bearing other kindred for Julie’s ultimate use. Julie will soon explain how she, the giraffe Paradex and the gazelle Gondo will spend the next couple of months getting to know each other.
In the meantime, I would like you to get to know these amphipods in a more real sense – well in a virtual way. No pith helmet or parka required. Check out this YouTube video of several different species of amphipods filmed in the wild kingdom of Antarctica. Marlin Perkins should be the narrator…
- Written by Chuck Amsler
At the group meeting, we decided that the afternoon dive would be to collect macroalgae for Julie. She, Kevin, boating coordinator David Moore, who was helping us today, and I had an easy boat ride across glassy calm waters with just a bit of small ice called brash ice to work around. We went to an island called Shortcut because it is along a "shortcut" of a route to some of the southern islands near station.
In my last post I talked about the unusual macroalga (seaweed), Ascoseira, that we traveled to the Lemaire Channel to collect the first week we were at Palmer. Julie and I dove at Shortcut today because it is the spot here where the normal form of Ascoseira is most common. Julie has been using the normal form to make biophysical comparisons with the long stipe form that we got in the Lemaire.
The question that Julie is asking is trying to understand why the Ascoseira in the Lemaire has the long stipes. Our colleague Dick Moe, who as I mentioned in the previous post as the first and only other person to report finding it, told me that the place he collected it had a lot of current. So does the Lemaire, at least sometimes, and we wonder if the long stipes are related to that.
Julie is making several different measurements of the physical characteristics of the stipes that are related to how they might handle the stress of strong current. In the photograph to the left you can see a shaved portion of one of the long stipes on being stretched by having weight added to the pan attached to the bottom. At the top is a meter that measures the force on the alga and Julie measures things like how much it stretches during the process.
I like to kid Julie that she is "torturing" the poor macroalgae as if they were in a medieval torture chamber and being put on "the rack." If you have never seen the movie The Princess Bride, you should (particularly if you need a heartwarming giggle). If you have seen or do see the film, you'll understand why I called where she was doing the experiments the "pit of despair."
We have also wondered about other ways in which the long stipe Ascoseira might be similar to or differ from the normal form. Kate talked about her friend PAM (an instrument to measure photosynthesis) in her last post. Kate made PAM measurements of the Lemaire Ascoseira both underwater there and in the aquarium back here at Palmer. She is doing the same with the normal form. The photo to the right was taken this afternoon of Kate and PAM making measurements in the aquarium of the normal Ascoseira Julie I and I collected.
Although Ascoseira is unusual in so many ways, big brown macroalgae are far from unusual here at Palmer and along the rest of the northern and central Western Antarctic Peninsula region. Big brown algae form undersea forests here in Antarctica. I like to tell people that if they think there are no forests here, they are wrong. They just are not looking in the right place. The right place is under the surface of the sea.
The YouTube site for our UAB in Antarctica web project has a video on The Forests of Antarctica that I put together in 2010. You can see it by clicking on the imbedded video on the left. National Geographic News did a much better job with the video I shot plus some professional video that UAB Media Relations provided. You can that on the web HERE.
Regardless of the source of the images and descriptions, the undersea forests here are amazing. The amount of macroalgae per unit area of the bottom is comparable to the giant kelp forests on the west coast of the US. As I mentioned in my last post, the giant brown algae here are not technically "kelps" but are very much kelp-like in appearance.
My PhD research was done on "true" kelps in the giant kelp forests of south and central California when I was at UC Santa Barbara. I guess one could call them Algae of Unusual Size. After working on much smaller (but no less interesting!) organisms for some years in between, I often marvel on how life has brought me back around to having part of my research being on an Antarctic analog of that earlier love, those giant kelps in California.
I'm in a beautiful place doing something I so enjoy both professionally and personally. And doing so with something akin to a macroalgal "love" I once thought I might not get to be with again. Although I have spent a fair bit of time at sea in between, I didn't even have to turn to piracy. Sometimes it really does work out as you wish.