Bermuda Field Course 2012 :: Daily Report
Day 06 | Tuesday, March 13, 2012
The sunrise here is spectacular. As the sun began to rise this morning by the “concrete beach” at BIOS, hundreds of small fishes began to jump out of the water onto the shore, seemingly to escape some predator. Being able to watch marine life at dawn is such a great way to start a day here in Bermuda. After breakfast (more eggs and french toast than I could handle), it was my group’s turn to survey Walsingham pond, a nearby saltwater mangrove pond. The previous night we had decided to split into two separate groups; one studying algae/other animal cover on mangrove roots and rock walls, and then ours, studying changes in Cassiopea xamachana (the upside down jellyfish) size with depth.
On entering the pond, I was astounded by the amount of jellyfish literally blanketing the pond bottom; there was so many that in some places the bottom just appeared to be sand, when in fact a closer look confirmed it was the pale colored jellyfish tentacles! For our experiment, we set up transects (essentially floating lines) at different depths, and swam down to do photo-quadrats at intervals along each transect. Later, we analyzed the sizes of jellyfish in each photo-quadrat to obtain our data. Each photo-quadrat was only about 0.25 m2, but there were over 30 jellyfish to measure in some! The other group surveying the mangrove roots and rock walls had to re-evaluate their methodology slightly after their initial survey, but they also obtained some interesting data on community composition.
After our surveys were complete, and we had thawed out from the surprisingly frigid waters in Bermuda, I had easily one of the most memorable experiences of the entire trip so far. We had all heard there were caves nearby, which have formed as a result of Bermuda’s limestone plateau and karst-type geology.. What we had not expected though, was to walk into a large cave opening to find a crystal clear aqua- blue pool within the cave, perfectly lit from the outside and over 12 meters deep! Unable to resist the temptation, we jumped in for a swim, only to see a network of underground channels and cave formations sitting silently below us in the blue water. This was one of those rare sights that really takes your breath away.
After returning to BIOS for another amazing dinner, our groups both spent hours analyzing data and running statistical analyses (or for some of us, struggling to wrap our heads around how to do them!). Eventually we were off to plan methods for another day-another survey.
The time we’ve spent here so far, though short, has given us a surprisinginsight into what exactly it takes to be a field biologist; insight rarely gained from any typical textbook-based course. Undoubtedly, these experiences will be invaluable for us in our future lives.
– Dan Link
Cassiopea photo quadrat
Taking the plunge!
View across road from Walsingham Pond