Today was our first day of pre-trimester field trips. Monday through Wednesday morning I have field trips for my Marine and Coastal Ecosystems class. Immediately following that, Wednesday through Friday I have a similar schedule for my Marine Biology class.
We started at 9am with my first lecture as an international student, going over what we’ll be learning in the course and the types of ecosystems and organisms we’ll be focusing on and discussing. After lecture we had a short break and met up at 10:30am at the bus station (conveniently right across the driveway from our temporary housing). With 37 students in tow, we drove to Lady Bay to take samples with plankton tows and test water quality. Our goal was to compare exposed, sheltered, and estuarine habitat invertebrate plankton communities in the water column. With a warning not to “insert your bare hand/arm into concealed rock crevices,” we divided into 4 groups in order to test a variety of ecosystems. Lady Bay Beach, Merri River estuary, shallow waters along the break wall, and deeper waters at the end of the break wall were all sampled, with 5 samples from each location. I ended up in a group that sampled from the end of the break wall.
The brownish long looking thing is a conical, elongated net with a small mesh size, designed to capture phytoplankton. We had some trouble at first (and so did our instructor) figuring out how to best lower the net into the water from the height we were at without getting air bubbles stuck in the net, messing up our sampling.
Once we decided to simply lower it in and drag it along the wall, things went much more smoothly. The five gallon bucket was used to collect water and rinse the outside of our net, allowing any phytoplankton stuck along the sides to flow into the container screwed to the bottom of the conical net.
While we were collecting our samples, we managed to capture a small weed fish (at least I think that’s what our instructor called it). I guess it is camouflaged to blend in with the seagrasses.
All of the phytoplankton samples we collected went into similar, labeled containers. When we were finished, we used a meter to collect water chemistry parameters and loaded back onto the bus.
We had a break for lunch and then met up again at 2:30pm to look at what we collected in the lab. We spent the next few hours poking through our samples with a plastic pipette under a dissecting microscope, trying to discern what we had managed to capture. Overall, most of what we collected fell in to several broad categories, such as amphipods, copepods, mussels, isopods, etc. Most of us didn’t seem to have a clue what half of them were, but we did our best. It’s difficult to identify minute creatures that you’ve never seen before and refuse to hold still! I do know though that I had lots of bivalves and a weird-looking shrimplike thing that my instructor identified as an isopod.
Once we were finished around 4:30pm, we wrote on the board whether we found each class of animal to be common, rare, or non-existent in our samples. Eventually we’ll be using the data to compare the different ecosystems and the organisms that live there. We have to have a few lectures first in order to learn more about each individual ecosystem we sampled.
All in all, it was a good experience today. The sun decided to hide for most of it (dragging the weather down to the 60’s), but tomorrow is supposed to be in the 80’s again with the promise of wading in the ocean in order to collect seagrass samples!