Monday, July 8, 2013

Natasha Christman: Phytoplankton Fun

Around the world, phytoplankton are the foundation of the marine food web. They can be bacteria, single-celled plants, or protists, each a phytoplankton based on its ability to photosynthesize, the capture of sunlight and derived energy production. Few are large enough to be seen by the naked eye and generally they drift freely in the sea, "wandering" as their Greek namesake "planktos" suggests. Altogether, the phytoplankton produce much of the dissolved oxygen present in the ocean waters and sequester a great deal of carbon dioxide as part of their photosynthesis.

Small sketches of some of the plankton observed in our collected samples. 

Natural levels of phytoplankton populations keep the ocean healthy and conducive to biodiversity. However, when pollutants and excess chemicals find their way into the water, the excess of nutrients prompt the phytoplankton populations to explode and to aggrandize primary productivity of the system. This process, known as eutrophication, alters the normal balance of the ecosystem. When the phytoplankton die, their decomposition depletes dissolved oxygen in the water. The surplus of phytoplankton decomposition against normal levels can result in hypoxia, where the lowered dissolved oxygen level negatively affects the aquatic ecosystem.

Earlier in the week we had again gone out for a research cruise in Bellingham Bay, an area experiencing seasonal hypoxia. We sampled nine different stations, getting an early insight to the seasonal hypoxia occurring in the bay,. In addition to water profiling, chlorophyll and nutrient samples, and turbidity measurements, we added several plankton tows to supplement the investigation of the phytoplanktons' relationship to these observed phenomena.

Raising the tow after plankton collection at a depth of 10 meters.

Now we are working on analyzing collected data and processing the samples collected on the cruises. Next week's research will include a larger sampling cruise that includes work on one of the coolest research tech pieces, the CTD.

1 comment:

  1. Thank you for your informative post! It would be interesting to find out if any coastal eutrophication had anything to do with agricultural run-off or if it is only due to seasonal upwelling.