Stories tagged chlorophyll


Aren’t budgets all about money? Don’t they track how many $$$ come in and how many $$$ go out?

That’s right; so what’s a carbon budget? A carbon budget tracks how much carbon, C, goes in and out of a natural area.

Right now, we’re worried about too much C going into our planet’s atmosphere. This excess C is causing global warming, sea level rise, ocean acidification and other environmental problems. These are BIG problems! We can begin to fix these problems if we do a carbon budget and really know how much carbon is where.

Carbon Budget Study Area: How much carbon is in the shallow, coastal seawater?
Carbon Budget Study Area: How much carbon is in the shallow, coastal seawater?Courtesy Sergio Signorini, North American Carbon Program
Along with others, scientists at the Center for Microbial Oceanography: Research & Education (C-MORE), based at the University of Hawai`i, have begun to track C in the ocean off the eastern United States. The study area includes a LOT of water! -- all the seawater from high tide out to 500 meters deep, shown by the black line in the map, in the Gulf of Maine (GoM), the Mid-Atlantic Bight (MAB), and the South Atlantic Bight (SAB.)

Imagine your money budget. Let’s say we track your $$$ in and out of 4 categories. Money comes into your pocket from 2 categories, mowing the neighbor’s lawn and babysitting. Money goes out when you pay for movies and snacks.

In the same way, scientists want to track C as it moves between the coastal water “pocket” and 4 nearby areas: the coastal land, the atmosphere above, seafloor below, and the deeper ocean offshore. Where is C leaving the coastal water? Where is it entering?

But wait! Coastal zones are only small slivers of water, compared to the open ocean around the world. Why bother to track carbon in coastal waters?

Ah ha! Coastal waters are very important in C budgeting. Notice the red color in the map above. Red means there's a lot of chlorophyll. Chlorophyll is the green pigment important in photosynthesis, the process that plants use to take in C and fix it as sugar. The red in the map shows that coastal waters are richer in carbon than the open ocean.

Understanding the C budget of coastal waters is one small but important step in solving global warming and other environmental problems.

Reference: Ocean Carbon & Biogeochemistry Winter 2010 OCB Newsletter; Vol. 3, No. 1.


surveying microbes at sea
surveying microbes at seaCourtesy C-MORE
Dr. Dan Repeta from the Woods Hole Oceanographic Institution (WHOI) is C-MORE’s Chief Scientist on the BiG RAPA expedition, which is conducting research off the coast of Chile. Dr. Repeta and his team of scientists are sampling the underwater microbial environment using a variety of instruments, including a water collector called a CTD (see educational resource below). Two interesting results have turned up in the CTD data:

  1. chlorophyll -- The greatest amount of the green pigment, representing floating microscopic plants in the sea known as phytoplankton, was found about 30 meters below the sea surface. (That's where oceanographers expect the most chlorophyll. Perhaps phytoplankton living at that depth must produce more chlorophyll in order to capture the lower light intensities, just like leaves are usually darker green if they're growing on a land plant in the shade). However, a surprise awaited oceanographers at 60 meters. At that depth, they discovered an unusual “secondary, deeper chlorophyll max," something not seen many other places in the world.
  2. Oxygen -- This gas enters the ocean primarily at the surface, from the air and also from phytoplankton photosynthesis. Bacteria and other heterotrophs consume the O2 as they metabolize. Therefore, oxygen is expected to decrease with depth. At BiG RAPA's Station 1 oxygen not only fell; it fell all the way to near zero.

Dr. Angel White and the CTD
Dr. Angel White and the CTDCourtesy Eric Grabowski, C-MORE
"Sea It Live" in some BiG RAPA videos. Join Dr. Angel White from Oregon State University as she demonstrates the CTD rosette. Then join Dr. Repeta for his Chief Scientist Station 1 Update .
*Educational resource = C-MORE Science Kit Ocean Conveyor Belt's Powerpoint, "Lesson 3: Using Data to Explore Ocean Processes "