Thursday, December 16, 2010
As of today we have complete most of our final assignments, including: four final presentations, two final papers, three final exams, and one herbarium. It has been a stressful past few weeks, but with one final left we have almost finished this semester. It does not feel like we have been here since September. As a way to get everyone together and take a break from studying we organized a holiday secret santa, so that everyone had to buy a gift for someone else in the program. Amazingly we all managed to keep it a secret from most of the group. This afternoon after we all finished our experimental design final we gathered at the Vernon house for some baked goods and presents. We went around and opened them so that everyone saw what was given. The gifts included great dive gifts, pets, warm weather clothes, and helpful things for Panama. It was a great break from the studying, and was great to see everyone together before we split up for winter break. Tomorrow we have our last final in Botany and then we move out of these houses to meet up again soon in Panama. This semester has gone by really fast.
Monday, December 6, 2010
Today we gave our presentations in our invertebrate class. Each student presented an invert of their choosing. Some of the animals included the the giant jellyfish Nemopilema nomurai, the elephant snail Scutus antipodes, the common octopus, the nudibranch, the seastar Pisaster ochraceus, and the nautilus. Presentation styles included powerpoint talks, movies, or a combination of the two. Many students included short videos of their organisms in action, either eating, moving, or attacking. The focus of the presentations was to discuss problems facing invertebrates having to do with global change, from climate change or human involvement. Each student also had to give possible ways that the organism would deal with the problems, adaptations or changes in behavior that would have to occur in order for the organism to respond.
My organism of study was Pisaster ochraceus a keystone sea star found in the northern Pacific Ocean. Although the sea star contains calcium carbonate spicules, when exposed to higher temperatures and higher concentrations of carbon dioxide the tissue mass doubled in size, showing that this organism has to potential to respond positively to the warming sea waters. Problems that this organism may face would be declines in its prey species, which are calcified organisms who may not be able to make shell material when carbon dioxide concentrations rise.
Overall, it was a great experience to learn about many different species, and to see how global change is affecting them currently and in the future.
Friday, December 3, 2010
Today in botany, we had the opportunity to make blancmange - a traditional Irish pudding made from Chondrus crispus, more commonly known as Irish Moss. Although you may not want to make it in a beaker like we did, here's a traditional recipe from lovetoknow.com so you can make it at home.
- 1 quart milk
- 1/3 ounce (a small handful) Irish moss
- 1/3 cup sugar
- ¼ teaspoon salt
- ½ teaspoon vanilla
- Prepare the moss by soaking and washing it in four changes of cold water, allowing it to soak about fifteen minutes the first time and five or ten minutes the succeeding times, picking it out of each water into the other with the fingers, carefully looking it over, and removing any sand or dark spots.
- Put the milk into a double boiler to heat.
- When boiling hot, put the washed moss into the hot milk and cook thirty minutes.
- The milk will not seem much thickened, but it will be solid when cold.
- Strain through a fine sieve, stirring the moss to allow all the milk to drain out.
- Add the remaining ingredients to the milk.
- Stir well to dissolve the sugar.
- Pour into a mold wet with cold water or pour into individual molds.
- When cold, turn out of the molds, and serve with cream or with sliced bananas and cream.
Tuesday, November 16, 2010
Sunday, November 7, 2010
Friday, November 5, 2010
For our experimental design class (a nice way of saying statistics for scientists), we split into groups to set up and run three different experiments that our professor Geoff Trussell and TA Catherine Matassa (a former Three Seas graduate) introduced us to. Each of them examined the effects of the presence of the green crab (Carcinus maenas), a predator to local Nahant snails. The top down/bottom up group looked at whether chemical cues in the water from the crabs affected how much algae the snails ate, the mechanical damage group looked at differences between the effects of chemical cues and physical damage to snail shells on snail growth, and the respirometry group is still running their experiment on how water temperatures in addition to chemical cues from the crabs affect the snails' respiration rates.
Carcinus maenas, the green crab.
Photo from: uri.edu
Littorina obtusata, the snail used in the damage experiment.
In the damage group, we learned about the time and effort that goes into the care and keeping of an experiment. Multiple times a day, we had to go to the Marine Science Center (MSC) just to make sure the water was flowing into our tanks, so that our snails and crabs would survive. We even had to check on weekends! It became a routine, though, and it was exciting to have something of our own to take care of for 5 weeks. Just last week, it was time to take down our experiment and weigh out all 120 of our snails (yes, 120 of them), to determine how much they grew, or didn't grow, over the length of the experiment. Luckily, with a team of 10, tasks were split up, and the work went quickly and smoothly. By quickly, I mean about 4 hours. A little bit of music on the radio helped keep us entertained while we waited almost two hours for the snails to dry so we could weigh them.
Here are a few pictures documenting the process of taking down our experiment:
Bobby is cleaning one of the jars we used to transport our snails back to the lab.
Josh and Liz are carefully opening the containers with the snails to keep them underwater, so we could record whether they were feeding or not.
Everyone having a good time cleaning the buckets. Want to leave it looking better than when we started.
A demonstration of the buoyant weight technique, to determine the weight of a snail when it is in water. This helps us when we want to determine the weights of the shell and the snail body tissue separately, instead of just the total weight of the snail.
Piper recording the buoyant weights of the snails, then leaving them out to dry.
The set up we used to photograph each snail in the experiment, so we could visually see how much the damaged shells grew back over 5 weeks.
Running and maintaining the experiment was a great experience, and now we get to delve into the statistics. How much did our snails grow when they were exposed to a crab or no crab, and did the damaged snails grow their shells back more or less than the undamaged snails? Crunching the numbers may be difficult, but the results that come out at the end will be the most interesting and will tell us a little bit more about snails that we did not know before.
To find out, we split into two groups and went SCUBA diving at each site taking along transect tapes, T-bars, and rugosity chains. Each dive team swam along the 30-meter transect and and used the T-bars to count the number of hermit crabs seen in the one meter to either side of the tape. We used the rugosity chain to figure out how complex the substrate was. A pre-measured chain is laid on the bottom and is conformed to any variations in substrate, such as rocks or valleys. We compared the length of the conformed chain to the actual length to find out if it was the same (sandy bottom) or shorter (rocky bottom).
There was a lot of variation in the number 0f hermit crabs that we found; some groups found only 14 0r 18, but one group found over 100! We looked at the data using methods that we've learned in our Experimental Design statistics course, but found that there wasn't really a difference in where hermit crabs live. This might be because they don't have to worry about finding the perfect home, since they carry their homes with them.
Although bottom type and beach location didn't affect the number of hermit crabs, we still got to combine what we've been learning in our classes to carry out an observational experiment.
Wednesday, November 3, 2010
Monday, October 18, 2010
Sunday, October 17, 2010
We surveyed at two sites around East Point, Cunner Ledge (relatively wave-exposed) and Canoe Beach Cove (wave-protected). Between surveys, there was time for an epic photo.
Then, it was on to Canoe Beach Cove to finish the surveys.
Saturday, October 16, 2010
The next salt marsh we went to was located behind Plum Island near Strawberry Hill. This was a much larger and much older marsh. This salt marsh was over 12ft (4m) thick and probably twice as old as the first one. We found some pannes and caught a few of the mummichog living in them as well. To top off our trip we stopped at Russell's Orchard on the way home. We all were able to enjoy some cider donuts and fudge before coming back to Nahant.
Nikki all muddy Russell's Orchard
All in all it was a great trip! It is always fun to go out in the field for labs and see what we are studying up close. We all came back a little muddier that when we left, especially Nikki, but it could have been worse. The Nor'easter we all thought would dampen our trip missed us completely! It was a beautiful and blustery day for a trip to the Great Marsh of Ipswich.