Marine and Costal Ecosystems & Marine Biology: Days 3-4 of Ocean Exploration

Wednesday started off at 9am with the goal of examining what larger species we could find in the Hopkins River Estuary. We were to use seine nets in order to explore the habitat. A seine net is basically a really long net (in our case only 6 meters) that you walk through the water with, attempting to corral species toward shore.

Seine Net

Seine Net

Our group made several attempts, but never caught anything in our net. If we would have caught anything, we were supposed to put it in a bucket or tray, depending on its size.

seine2

Equipment

seine3

Seine Netting

A one or two groups caught some small fish, but nothing major. I think my favorite fish that one of the other groups caught was a flounder. They’re odd little fish with both eyes on the same side of their body, and they are awesome masters of disguise.

seine5

Flounder

Flounder Close-Up

Flounder Close-Up

As a final attempt, we organized all the groups into one team, trying to corral anything we could find towards shore.

seine6

Team Effort

We were a bit more successful and caught several fish this round.

Fish!

Fish!

seine8

More Fish!

I’m not exactly sure what they all are, but we caught them! Once we finished, we released the fish and headed back to the University. We had a break for lunch before heading over to the pool a little after 2pm to be ready for the swim test at 3pm. For the next pre-trimester field trip, Marine Biology, we’ll have to opportunity to snorkel on Friday. In order to do so, we needed to pass a rigorous swimming test to prove we weren’t going to drown on University time. We swam 400 meters, snorkeled 1 kilometer with fins and a mask, treaded water for 12 minutes, snorkeled 25 meters without breathing, snorkeled 50 meters with three breaths, towed a person 25 meters, cleared our masks underwater, and retrieved an object from a depth of 2 meters. There were a lot of us, so to keep us organized they wrote numbers on our arms with sharpie.

Swimmer #14

Swimmer #14

We finished around 5pm with all swimmers passing the test. Our instructor said this was the first time she had this happen and was surprised it was such a large group! She told Natalie and I that we were also the first American students she’s had pass the test. Woot!

At 6:30pm we had to meet in the cafeteria (or caff as it’s known here) for our pizza welcome dinner and scavenger trap making for the beginning of our Marine Biology field trip. Our traps consisted of a 1.5 mL bottle with the top cut off and inverted.

photo 1

Homemade Scavenger Trap

At 8pm we headed to the Hopkins River Estuary to set our traps. We were going to be setting them at night, pulling them back in the morning, and resetting them to sample during the day. We placed a little sand in the bottom to weigh it down, threaded our zip-ties (which you can see red and blue sticking off the top of my trap) along a bamboo pole, and left them sit in about 1 meter of water. The plan was to explore some rocky coastline near Stingray Bay afterwards to see what nocturnal coastline life we could find, but weather conditions were to poor to safely do that part of our lab (it was really windy and the waves were quite large), so we ended up retiring back to the University earlier than expected, which was about 9:15pm.

In the morning, we went to check our traps at 9am. Sadly, my trap didn’t seem to attract any critters.

Trap and Sieve

Trap and Sieve

One of the guys in our group managed to catch four Nassarius (snail), a goby (fish), and two bream (fish). No one else in my group caught anything.

A Whole Lotta Nothingness

A Whole Lotta Nothingness

We reset our traps in order to see what we could catch by 4pm and prepared to capture some razor clams.

Trap Set for the Day

Trap Set for the Day

Bamboo Poles Marking the Traps

Bamboo Poles Marking the Traps

My trap is to the left of the one with the yellow zip-tie on top.

My trap is to the left of the one with the barely visible yellow zip-tie on top.

For our experiments later on in the afternoon, we needed to collect 10 live razor clams and six empty shells. These little guys like to bury themselves in the sand, so at least two people from each group needed to don waders and wander out into the estuary with a bait pump and sieve.

Searching for Razor Clams

Searching for Razor Clams

Gotcha!

Gotcha!

When all the groups were finished we headed back to the University and worked with our groups for a while before lunch. On Friday, we would be doing a scavenger hunt for 20 different species. These assigned species were different for each group, and all we were given was the scientific name. We spent time looking up the common name, where it might be found, its reproductive cycle, and what method it uses to find food (filter feeder, scavenger, etc.).

After lunch, at 1pm,  we started a series of four experiments with snails. In our first experiment, we were looking to see how Nassarius (snails) would respond to chemical cues from food items (in this case snail juice versus water, and crushed razor clam shell versus crushed razor clam). We set up a series of containers including one of our variables and timed how long it took the snail to respond to the prey and how long it took it to reach the prey. Yes… we sat there and timed snails! Some of them, such as the snails that had been selected to receive the water variable, were incredibly boring to watch. As one might predict, they didn’t respond at all! Others, such as the snails that received whole, crushed razor clams could really move!

Snail Experiment #1

Snail Experiment #1

Our Series of Experiments for #1

Our Series of Experiments for #1

More of Experiment #1

More of Experiment #1. You can sort of see the crushed shell fragments in some of the containers.

For our second experiment, we incorporated a competition factor. We had types of variables running, feeding conspecifics, non-feeding conspecifics, and no conspecifics. Basically we had a snail and pilchard (another name for a sardine) in each container. They would either have nothing in the container with them, another species of snail in the container with them (Cominella), or the empty shell from a Cominella in the container with them. Once again, we timed them to see how long it took them to respond to the prey, reach the prey, and begin feeding upon the prey. Some snails got right down to business and found their food. Others wandered aimlessly in whatever direction they pleased.

Experiment #2

Experiment #2. You can see the pilchard head and the two different snail species.

Another view of Experiment #2

Another view of Experiment #2

For our third experiment, we attempted to examine if hungry scavengers are quicker to find food than those that have been fed, and for our final experiment, we attempted to see if scavengers would respond to dead and decaying plant and animal material differently that live material. My group divided into two teams, and I worked on the first two experiments. Other individuals in my group performed the third and fourth experiments.

When we finished, Natalie and I went with our instructor, Alicia, to get wet suits for snorkeling on Friday. Then we all went down to the Hopkins River Estuary to check our traps for the final time. Once again, mine came up empty as well as the rest of my group members, save the same individual who caught animals the first time. He caught another two bream and goby.

After we got back it was time to move out of the temporary residences we had been staying in and into our residences for the school year. I’m in Sherwood 2B, and the buildings are really nice (for a student residence anyways).

We each have our own individual rooms with a plethora of closet space.

Desk and Bed (Right Hand Side of the Room)

Desk and Bed (Right Hand Side of the Room)

Closet and Window (Left Hand Side of the Room)

Closet and Window (Left Hand Side of the Room)

The kitchens here are brand new, and we have a fabulous view of the Hopkins River through our window.

photo 1

Kitchen Sink and Window

Oven Area

Oven Area

Refrigerator and Freezer

Refrigerator and Freezer

We have a common living area as well.

Living Area

Living Area

There’s also a laundry room with a washer and dryer for all of us to share. I’ve been told that there will be six people in total living in this building, which is built to hold eight (I believe). I think most people are coming on Sunday, so we’ll see how that goes! For now, I’ve got all my stuff moved in and settled. I’m ready to go!

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