I have been making good progress in my quest to analyze all of the summer cruise footage and have all but finished organizing the winter cruise data in order to make easy use of the data toward the end of my research. I should be able to reach my goals in analyzing each video within three weeks and may be able to finish up sometime before that deadline as my process of analysis has been speeding up steadily through practice. I have observed few pyrosomes in the videos that I’ve reviewed so far, so future footage may prove more time consuming when more begin to appear. I decided to start my analysis on the final CTD cast from the summer cruise, working backwards toward the first in order to account for some mislabeling. The final few CTD casts where performed in very choppy water and I have been able to identify surprisingly few pyrosomes near the water’s surface in these casts, regardless of water depth, distance from shore, or time of day. Pyrosomes are known to perform diel vertical migrations (meaning a migration over a 24-hour period) that place them nearer to surface water during the night, something which appeared to be supported by my experiences during the cruise. I would sometimes find pyrosomes floating directly at the surface during the night when the sea state was calm, but the general lack of them represented in the footage taken from rough water may hint at a connection between sea state and pyrosome distribution. I have also observed a fairly concentrated population of macroscopic zooplankton such as jellies and krill, and the presence of several schools of fish in these videos, which may be evidence of another connection between zooplankton, fish, and pyrosome abundance. The frequency of pyrosome consumption by fish is not something which has been researched in depth at this point in time and, while I predict that the lack of pyrosomes in fish populated waters has more to do with sea state and distance to shore than to direct interaction between animals, I will be interested to document fish and pyrosome abundance in the future.
An example of pyrosome sizes found during the S18 cruise.
Hello there! My name is Matthew Gimpelevich and I am currently an undergraduate student in my third year of oceanography and engineering at Seattle Central College in Seattle, Washington. I’m lucky enough to be working in the Sutherland lab at the Oregon Institute of Marine Biology where I get to formulate my own methods of studying the pyrosome, Pyrosoma atlanticum, which has recently migrated up the Pacific coast from warmer waters! As an REU intern, I look forward to developing research techniques and methods of organizing and maintaining my own projects!