This was my first taste of real science! There are so many statistical, logistical, and experimental problems to work out. For this experiment some of the issues that can make things difficult are: a lack of high enough tides, difficulties getting to a particular marsh, a lack of channels to put cubitainers in, a lack of marsh sites that have all of the habitats that we are looking for, inaccessibility to desirable sites because of private land ownership, problems running the experiment, slight mistakes in chamber building, inadequate sites to represent the whole estuary system, etc, etc.
Here’s a video of the different zones in the salt marsh: http://upload.wikimedia.org/wikipedia/en/thumb/5/56/Salt_pannes_and_pools_high_and_low_tide.gif/340px-Salt_pannes_and_pools_high_and_low_tide.gif
The biggest aspect of working on this project is that everything here revolves around the tides. So, if the high tide is not until late, we are out late, if the high tide is really early, we are out really early. Because of this, I’ve spent several late nights this past week scouting potential sites up and down the estuary at high tide to make sure that they low marsh that we are trying to sample is flooding at high tide. A lot of the time, the tides are not high enough to flood the low marsh, so when they are we must act fast to run our experiments on those days.
After running that first test, I realized that I need to start doing pushups to get stronger. I am not particularly weak, but at only 100lbs lifting 20 gallon water jugs and carrying 10 gallon cubitainers in and out of the marsh requires a lot of energy. I’m hoping that by the end of the summer I’ll be much more in shape.
This week, we will continue preparing for our next experiment which will begin around the 13th of July. We are switching to “bladders” instead of cubitainers so we need to figure out which bladder will work the best. We have to finalize the sites that we are going to go to for our experiment. We also need to buy more supplies and continue to figure out the logistics to make this experiment as successful as it can be. I’m hoping that this week will be slower (relatively) than last week. Three late nights a week are no fun, but I know I have more coming up. I’m excited though because I get to do science and field work all day which is a lot of fun and is definitely my passion.
Check out my personal blog to see what I’m up to outside of work! Sara Duncan
Another great blog Sara!! I’m sure your old elementary and high school science teachers would love to read them.Hope your week goes well.
So what about filtering the samples would change the nitrate readings? Is it a special kind of filter that’s used?
Great question Sarah! The analyzer that we use is a spectrophotometer which means that it shines light through a sample at certain wavelenghts. The nitrate absorbs light at a certain wavelength so the less light reaching the sensor on the other side, the more nitrate in the sample. We think that the presence of suspended particles in the sample was able to cause our nitrate levels to read 4-5 micromolar lower than they were supposed to be. Removing the suspended particles using a filter gives us the correct measurements. Problem solved!