Class on October 25 2018

Lucy coordinated a plankton sampling field trip to the URI Bay Campus dock. The students arrived at low tide to drop their nets into the water and collect samples. One group focused on a 125 micron net to capture zooplankton and the other used a 20 micron net to catch phytoplankton.

The nets take a bit of work to sink to the bottom. The goal was to get the sampling jar end of the net to barely touch bottom. Seems the students did a good job since the measuring of wet rope suggested the ropes had been let out to between 6.52 and 6.56 meters (with about seven minutes of tidal change in between drops).

Lucy provided a spreadsheet to use in following the steps that would estimate the amount of plankton in the bay

The processes diverged as to quantifying phytoplankton and zooplankton.

Phytoplankton assessment required the filtration of 200 ml of water through a cotton filter that could capture chlorophyl (students used a pump system to run two samples at a time). A floroscope then suggested the amount of cholophyl by way of amount of florescence.

Zooplankton assessment required the sample be filtered through a coarse filter whereby the difference between water volume remaining after filtration and before filtration was an important intermediate value.