We have been zigzagging up and down the Florida Straits for the last two weeks. This photo, from two days ago, shows our ship track (in blue) and drifter track (in red).

Our first study was the Spatial Study, where we deployed a drifter at the beginning of the day, and then followed it, sampling with ISIIS and MOCNESS in a zig-zag track for the whole day. We started our cruise sampling near Miami and Bimini, Bahamas, and finished up the Spatial Study in the FL Keys.

Research Vessel F.G. Walton Smith during the OSTRICH Cruise, June 2014. Photo by Cedric Guigand, taken with a Phantom DJI drone.

In the second leg of our cruise (which concludes tonight), we have been sampling in the Lagrangian Study, which lasted a total of 4 days. We deployed a drifter in the Lower Keys at the beginning of the study and have been following it continuously, sampling with ISIIS and MOCNESS.

The idea is that by following a drifter, we will be continuously sampling the same body of water. Consider this analogy: you are sampling a fast moving stream. If you stand at a fixed point on land and continuously sample, you sample different parts of the stream because it is constantly flowing in front of you. However, if you build a raft and float down the stream with it, sampling along the way, then you are actually sampling the same part of the stream at different points in time. The latter case is what we are doing. The Gulf Stream / Florida Current is our fast moving “stream” and we are drifting with the stream in a fancy raft, sampling along the way.

R/V F.G. Walton Smith, aerial view of the back deck, with ISIIS on board. Photo by Cedric Guigand

Continue following our updates on the ISIIS Facebook page as we conclude our 18-day cruise this week.