Even Phytoplankton Get Hungry

So far, I have completed two experiments while aboard the R/V Atlantis.

Costa Rica Thermal Dome

 Located in the Eastern Tropical Pacific, the Costa Rica Thermal Dome (CRTD) is a marine biodiversity hotspot known for an abundance of phytoplankton Synechococcus. For my first experiment, I was looking to determine if additions of trace metals would impact the physiology of marine microbes from the CRTD. After three days, here are the results:

 

As shown, the control and nutrient addition treatments resemble similar amounts of chlorophyll, which may indicate that the nutrients do not have an immediate impact on the physiology of the microbes. However, after six days, the experiment reflect contrasting results:

 

According to the figure, the chlorophyll in the control has drastically dropped while treatments with cobalt, iron, and iron and cobalt remain as relatively the highest measurements. Therefore, although the biomass does not seem to nutrient limited in the CRTD, the additions of nutrients seem to prolong exponential growth of phytoplankton.