Monday, August 5, 2013

Cris - Weeks 5 and 6: Surprise Settlement, Sabotage, and a (single) Gooseneck

Unidentified mass covering mooring 7
On week 4 I set out a seventh mooring with 4 settlement plates between sites 4 and 5 (seen here), which I then collected on week 5. There was a significant difference in the settling of species across sites 4 and 5, the latter having a large number of barnacles. This additional site is also where the basin is split into the inner and outer portions, and collecting data would give a better idea of the distribution of fouling species across the basin. When I brought my plates up for inspection under the microscope, the seventh site had very different settlement. I was unable to identify what covered most of the plates (shown above), a white globular mass with no visible structures. They were very delicate and would burst when I rinsed the plate using a wash bottle to remove the detritus. The next time I set out mooring 7 I will leave it out for two weeks so that I may see the unknown mass at a later point in development. 

Gooseneck barnacle
Unfortunately, during week 4 my mooring at site 3 was taken out of the water and left on the dock for at least 6 hours. I found it on the dock wrapped up in its support rope after being notified by a fellow intern. Although the settlement remained relatively close to the observed pattern of previous weeks for that site, the ascidian Botryllous schlosseri was phenotypically different than what I had seen before. It was in a more immature state than what I have been seeing every week. This may be due to stress the animal incurred while being face down on the cement and out of the water. On the plus side, I found the only gooseneck barnacle (above) that I have seen on any of my plates throughout the basin. It was very active and had a peduncle (the "gooseneck") that was about half the length of its body. 

Distaplia occidentalis
By far the most abundant organism I have seen these past two weeks has been the colonial ascidian Distaplia occidentalis (right). It is also very abundant as an adult on the sides of the docks throughout all sites, but it has had especially high settlement at my second mooring in the inner basin. On a single plate I found over 90 individual zooids, and some with their tails still attached from their larval stage. It is very easy to see the pharyngeal basket and the cilia within it using just a dissecting scope and fiber optic lighting. 

The coast north of Blacklock Point
On the weekend I had some free time and was able to go to Shore Acres State Park with two other interns while they did some field work with their settlement plates.  It was a very nice day and I was able to explore the park and see the botanical gardens. I also spent some time at Blacklock Point, a few miles south of Bandon. The views were spectacular and there were many trails to choose from, leading down to the beach, through the forest, or along the cliff. Until next week, cheers!

Shore Acres State Park

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