Program on the Environment

Summary:

This paper focuses on phytoplankton biomass at the Bering Sea. It wants to address how does phytoplankton biomass in the Bering Sea Basin change seasonally between the spring and fall blooms and how does this year compare to the data of the previous 13 years? Firstly, I prepared and read samples taken by a cruise during Spring of this current year under a fluorometer. After that, I compared and contracted the data from a couple of stations between spring and fall and between year to year, taking into consideration water temperature and ice coverage. The results of the study were that the results in Chla concentration between spring and fall show greater variation among samples during spring. As for this current year data, the average concentrations fall under the lower end of concentration oscillations. These results might suggest a late spring bloom, and poor recruitment of age-0 fish for 2018. 

Why I did it:

Phytoplankton is the base of the food web on the Bering Sea. Leaving beings tend to spend most of the energy the get by consuming mass in body functions such as heartbeats or moving rather than transforming it into mas of their own such as fat due to thermodynamics. The more mass is present from primary producers, the more mass the ecosystem can sustain from consumers up in the food web such as fish like cod. Additionally, the Bering Sea is the home of several fisheries that are very important both for the economy and the food security of the Pacific Northwest. Nevertheless, the dynamics of phytoplankton bloom are hard to predict but necessary to understand due to the uncertainty of a future with climate change. Therefore, understanding the dynamics is critically important.

How I did it:

To determine phytoplankton biomass, I used Chla concentration levels as a proxy. The internship for the capstone project consisted of 2 distinct faces. Firstly, I prepared and read samples taken by a cruise during Spring of this current year. The process consisted in: diluting filters with the chlorophyll in acetone overnight on a test-tube, shake the tubes on a vortexer to liberate the pigment, put the tubes in a centrifuge, and then measuring the concentration of chlorophyll in a fluorometer. After that, I compare and contracted the data from a couple of scientific stations called Mooring 2 and Mooring 4, regarding this year and the one from previous years while also examining the data from spring and fall, taking into consideration water temperature and ice coverage.

What I discovered:

The results of the study were that the Chlorophyll a concentration levels between spring and fall show greater variation among samples during spring. Fall samples tended to show moderate levels of concentration levels with high statistical variation. Spring samples fall under two categories. On the one hand there are years with significant average levels of chlorophyll concentration with high uncertainty; on the other hand, there were years with low concentration averages and low uncertainty. The current year data falls under the second category, M2 and M4 had average concentrations 1.236167 ± 0.343814 and 0.934 μg/L respectively. For context, while these levels are not unheard, they are relatively near zero.

What I learned:

• To work in a professional lab environment.
• To understand how to use of machinery such as fluorometers, centrifuge, and vortexers.
• To improve my statistical analysis skills.
• To work in projects that combine research of scholarly articles and data taken from the lab.

The Big Picture:

These results might suggest a late spring bloom, and subsequently relatively poor survival levels of recently born fish for this year. Nevertheless, because the area evaluated is relatively small the study must be taken as only preliminary.