Greetings from the R/V Blazing Seven! I'm your current teacher at sea from Sarasota, FL. I'm very excited to be joining scientists and students from Texas A&M Galveston and Nova Southeastern University to sample the larvae and juveniles of pelagic fishes using plankton nets. You can read more about the research done by Jay Rooker, PhD here.
We left Port Fourchon, LA early this morning and just made it to our first sampling site to collect plankton. Plankton are tiny (usually) plants or animals that drift with the currents. The focus of this cruise is animal plankton, referred to as zooplankton. The basic design of a plankton net is a large area of mesh that ends in a collection bucket. The two nets we will be using during this cruise will sample at different depths and have different mesh sizes.
The first net, rightfully named a bongo net, is deployed from the stern. The reason it has two nets is that one net has a mesh size of 333 microns and the other has a mesh size of 500 microns allowing us to sample two different sizes of zooplankton. The bongo net is hoisted off the back of the boat using a winch. After entering the water it sinks down to a depth of 100 meters (328 feet)! When the nets are brought back up to the surface they are carefully rinsed with seawater to ensure that all of the organisms make it into the collection buckets at the bottom.
The second, a neuston net, is deployed from the side of the ship and samples at the water's surface.
Each sample from the plankton nets contain algae and a wide variety of of organisms from copepods to larval tuna. The samples are placed in a freezer for identification at a later date. We collected a larval tuna and a sargassum fish!
In addition to targeting larval and juvenile pelagic fishes, we are collecting samples for other labs involved with the DEEPEND Consortium for their research as well. I’ll get into that more later. Our next stop is coming up soon!