Environmental Protection Agency Narragansett Bay Commission University of Rhode Island Office of Marine Programs

Estuarine Science

Chlorophyll a

1. What is chlorophyll a?
2. How do we measure chlorophyll a?
3. What are the chlorophyll a values in Narragansett Bay?
4. What can we learn about Narragansett Bay by measuring chlorophyll a?


3. What are the chlorophyll a values in Narragansett Bay?

The amount of chlorophyll in Narragansett Bay is highly variable throughout the Bay. In general, there are winter-spring diatom blooms, which cause peaks in the chlorophyll concentration. There is often a second, smaller bloom in summer. The chlorophyll a concentration will generally be higher in the northern part of the Bay. Chlorophyll a concentrations will be highest near, but usually not at, the water surface. Chlorophyll is measured in micrograms per liter. The winter-spring blooms frequently see chlorophyll values above 75 micrograms per liter.


Narragansett Bay Chlorophyll
(Click for larger image)
This image shows the chlorophyll a in northern Narragansett Bay from a satellite. Red colors are the highest concentrations of chlorophyll and the dark blue and purple colors are the lowest chlorophyll concentrations. Image courtesy Dr. John Mustard, Brown University. http://www.planetary.brown.edu/~mustard/apurva/index.html

1. What is chlorophyll a?
2. How do we measure chlorophyll a?
3. What are the chlorophyll a values in Narragansett Bay?
4. What can we learn about Narragansett Bay by measuring chlorophyll a?

       


(Image credits are listed in Image Index)

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