Thursday 10/25
Today team Valkayeri was proactive and got ready to boat to our intended collection location (Isthmus Reef) right after breakfast. However, after some time waiting to hear from the dock-managers and other staff, it was decreed that the dock would be closed due to a small craft advisory and threat of hefty wind gusts. Since we had gone through the trouble of getting everything ready, Valkayeri and Sara decided to practice fish surveys in BFC. The visibility was poor due to the swell and blustery winds, but we honed in on our techniques a little bit. We hope to get some difference in fish abundance and diversity depending on distance of the plot from the kelp forest fringe/interface.
After lunch, we went to Two Harbors via van to collect potential algae for our physiological preference project. We saw some pretty interesting kelpfish and sculpins in the shallows, and collected Egregia. The standard way of drying algae for a wet weight is by using the "hand-powered centrifuge", also known as a salad spinner. Loose algae is placed into nylon stockings before being spun. Ecology projects often are an amalgamation of arts and crafts time, ordinary object innovations, and seemingly simple projects that beget big-picture results. Preeeeetty cool!
We have narrowed down the preference choices for our Lithopoma. Egregia is an excellent candidate for testing snail size and capacity to eat algae of different morphology and texture, since the young parts of the alga are thin, bladed, and pliable, while the older parts of the alga have a thick stipe with dense thin strings. By using one species with multiple "types", we can mostly eliminate other differences, such as potential chemical differences that might arise with using multiple species. We spun both young and old Egregia and set up two tests-containers- one with small Lithopoma and the other with large Lithopoma. All samples of Egregia had about 7.0g of algae. We hope to see a discrepancy in choice and eating methods between the sizes of snail. We've already seen some preliminary results, but only by repeating the experiment can we find actual results.
Above: A tiny Navanax on one of our Lithopoma!
Older Egregia nibbled on by large and small Lithopoma, respectively
A sample of the end of an Egregia trial. This guy did work on the older Egregia!
A snail trial run
Friday 10/26
In the morning and early afternoon, we collected algae from Isthmus Reef. We brought it back to the dock and did the freshwater rinse in a bucket at the dive locker. Immediately after rinsing it, we took it to our spot in Big Fisherman's Cove and installed it in our plots. This was the second set of plots at BFC. We observed that plot #12 was missing an entire plant and the majority of another plant.
Sunday 10/28
We began our first dive at 9:45 at Isthmus Reef to collect the last batch of Dictyota for the final plot implementation at Lion's Head. Eric, Valerie and I functioned efficiently; we were done within 15-20 minutes. After returning to WMSC, we rinsed the Dictyota in our standard way (4 plants in freshwater for 30 seconds) down by the rinse tubs. We placed the samples in plastic bags with seawater back into the buckets and cooler, and made way for Lion's Head. Both the swell and wind were low and pleasant. We began our next dive at 11:30 and put out 7 plots within about 30 minutes.
We began to starve our snails (for 24 hours) to prepare them for formal testing over the next week! One snail was missing and we were unable to find it in surrounding tanks in the lab.
No comments:
Post a Comment