Sorry that this is late! I am lucky if I am able to sit in front of a computer for any length of time, so I have been working on it every chance I get. Since my time here is more than halfway over, I will fill you in on some of my reflections on my internship to date, but first a summary of the previous week. Monday and Tuesday of last week was spent preparing for our field work. This was the project that I was in charge of, so I had to make sure that everything ran smoothly. As you know, this project is to test whether or not there is some sort of microbial processes going on during the night that I are not going on during the day. We received some interesting results with “dark” (white PVC) chambers versus “light” (clear acrylic) chambers in previous tests, so we incorporated both into our experiment. The way the experiment was set up, was that we went to two locations where we deployed six chambers at each (three dark and three light) in sets of two at three different sites. We hypothesized that there would be a clear difference between the dark chambers and light chambers during the day since we have seen this in preliminary experiments in the past (we expect there to be no photosynthesis occurring in the dark chambers to drawdown nutrients, while there would be in the light). As for the night experiment, since we have seen some drawdown at night in the past with light chambers even though there is no photosynthesis occurring at night, we hypothesized that there may be some microbial activity occurring at night that isn’t occurring during the day.
As far as actually deploying the chambers and running the experiment, I would grade myself a B average which is pretty good for my first time. Everyone was still getting used to deploying the bladders and some miscommunication between Caitlin and I led us to bring one of the wrong chambers which we had to go back to the lab and exchange. Overall, running the experiment was a success. We finished our deployment right as the tide came in. The next day when we deployed our chambers at the other site, it went much better and faster and we beat the tide even though we were running late.
The most exciting part about doing these experiments is running our samples through the ISUS to get some preliminary results on nitrate values. The daytime results came out as expected with little to no drawdown in the dark chambers while there was significant drawdown in the light chambers. The night time results were much more peculiar. We would expect to see no difference between the dark chambers and light chambers at night as no photosynthesis is occurring due to lack of light, but we still had a significant drawdown in the light (clear) chambers while there was no drawdown in the dark chambers. How could this be? Our worry was that something was going on with the clear acrylic chambers themselves that was causing nutrient (particularly nitrate) uptake or something was causing the nitrate values to read lower than they should have. Since the next day we were preparing to go out and run more experiments during the weekend, I wanted to get to the bottom of this before we pushed ahead just in case something was seriously wrong. So on Friday, Caitlin and I, ran a mini experiment by adding our artificial sea water to a dark chamber and a light chamber and sealed it at both ends to see if there was a change. After letting the water sit inside the chambers for a few hours, we took samples and waited anxiously in the lab to run them to see if there was a difference. If there was a difference, then we knew that there was something wrong with the acrylic chambers all along. We ran the sample from the dark chamber and the results came out normal as we had expected. Then we crossed our fingers that the sample from the light chamber would be the same. But, when we ran that sample we discovered that the nitrate concentration was 8-10µm less (which is a lot less) than the dark chamber. This is not good news because it potentially means that all of the work and all of the data collected up to this point is virtually useless! Since we got these results, we decided that it would be unwise to move ahead with our field work for the weekend, so one positive was that I got the weekend off. Because of these results, it looks like I could have came to the midsummer check-in since all of Friday was just spent preparing for more field work, but of course we didn’t find out about this major issue until about 5:00pm- bummer. On Sunday afternoon, Caitlin and Jody, ran another little experiment by filling an acrylic chamber with ultra pure water to see if the results reflected a nutrient concentration as they should. Fortunately, after an hour or two of letting the water incubate in the chamber we got a negative concentration. Given the circumstances, this is good news because it means that the acrylic chamber is not in fact drawing down our nutrients, but is only causing the ISUS to read a lower nutrient concentration than it should. This is rather unfortunate though because it means that we cannot use the ISUS to get instant results, so we have to wait a month or two for all of the results to come back from the wet lab at UC Santa Barbara – unless of course those results are compromised too. Eek!
Unluckily, there is little time to think about what to do next because this week I have been plummeted into helping with another project. For this project, we will be measuring the nutrient uptake of a sea grass flume at Winant marsh. In order to do this, we must measure the flow of the water in the channel at one location and take water samples at three locations during four consecutive low tides. As you probably know, there are two low tides during a period of 24 hours so one sampling period will be during the day and one will be at night. Each of these sampling periods will be about eight hours long. Thankfully I was assigned two day shifts instead of any night shifts, so I won’t be sampling during the wee hours of the night, but I do have to be at work at 5:30am tomorrow and Wednesday. I’ll let you know how it goes in my next blog!
Since I was not able to attend the midsummer check-in, I will inform you of my reflections to date:
- First, since I am a rather small person, lugging 20L bladders full of water in and out of the marsh is very difficult for me. I enjoy being outside doing field work, but some of it is pretty intense. For my graduate studies, I need to make sure that I find a research project that I enjoy but does not involve something so physically demanding.
- I do not like marshes. They are muddy and full of hidden holes and channels. Working in them is rather difficult. I think I’d rather study in the woods, on a mountain, at a lake, or at a stream.
- Nature is full of unforeseen and uncontrollable variables. For the experiment that I have been doing so far, there are so many curve balls that nature has thrown at us, that I think a project like this would drive me crazy if I had to do this long term. I do enjoy the environment, but I think that I need to find something that I can have a little more control over all the unknowns. This internship has shown me that I am more interested in focusing on the human interactions with the environment versus dealing with nature itself.
I certainly can in no way say that I am not enjoying my internship. I love getting up and going to work every day and I think that this experience is pointing me in the right direction and is helping me figure out what I want to do with the rest of my life even if it is not exactly this.
Check out my personal blog: Sara Duncan