NOAA Teacher at Sea
Aboard NOAA Ship Gordon Gunter
April 29-May 11, 2013
Weather Data from the Bridge: Air Temperature – 12.20°C or 54°F, Sea Temperature 10.16°C or 50°F, Wind Speed- 9.24 kts, Relative Humidity 94%, Barometric Pressure- 1021.05 mb.
Science and Technology Log: Whale work can be intense and exciting, or slow and frustrating. A good day at work is when the weather cooperates the same time the whales cooperate. So far no one is playing nice. Fog has been the enemy for the last two days, making flying-bridge operations nearly impossible. Unless a whale swims up to our ship and jumps in for lunch, we aren’t going to be able to see it. Our watch efforts get moved to the bridge where the ship is controlled, and while it’s a good time chatting with the NOAA Corps officers, I’d rather be sighting whales.
For me however, this ship is like a small university on the sea with free tuition. Everyone here knows much more than I do about science, so days like these are spent asking questions. I wanted to focus this blog post on a question that came from my Tecumseh Middle School eighth grade students. They have been following my blog and following the NOAA Ship Gordon Gunter using the NOAA Ship Tracker. The ship tracker can be used to locate any ship in the NOAA fleet on its current cruise or in the last twelve months. Current weather data from the ship can also be displayed.
My students noticed that our ship was staying near the continental shelf, or Georges Bank, and wanted to know if it would be a better idea to look for whales in deeper ocean. I turned to Woods Hole Oceanographic Institute scientist onboard, Dr. Mark Baumgartner (yet another superhero), for answers. He basically told me, the whales go where the food is most abundant.
North Atlantic Right Whales eat a zooplankton named Calanus finmarchicus or just Calanus. This tiny crustacean is packed with lots of calories in an internal structure called a lipid sac. In order to grow and develop a hearty lipid sac, the Calanus require lots of phytoplankton. In order to be a yummy and nutritious treat for the Calanus, the phytoplankton need nutrients in the form of nitrogen and phosphorous, water, and sunlight. Nutrients and water are abundant for the phytoplankton, but in order to get the needed sunlight for photosynthesis, the phytoplankton must be as close to sunlight as possible.
Simply put the food chain links together like this: sunlight (source of energy), phytoplankton (producer), Calanus (primary consumer), and right whale (secondary consumer). The topography of the ocean near Georges Bank and the weather over the North Atlantic provide two things for this simple food chain: upwelling and wind.
Upwelling is a phenomenon that occurs in ocean waters when wind and a continental structure circulate water, allowing the cold nutrient rich water on the bottom to replace water on the top. The phytoplankton at the bottom essentially get a free ride to the top of the ocean where they are able perform photosynthesis. The Calanus can feed on the nutrient rich phytoplankton, and the whales can feed on the Calanus. This cycling allows the whales to feed close to the surface, where they need to be in order to breathe. If a whale has to dive deep for food, energy is wasted on the dive. It is more efficient to be able to get a good meal as close to the surface as possible.
According to Dr. Baumgartner, a Northern Right Whale needs to eat 1-2 billion Calanus per day. This amount of zooplankton has the same weight as a wet Volkswagen beetle, and is the caloric equivalent of eating 3000 Big Macs per day. So there you have it, TMS 8th graders. The whales go where the food is…
Personal Log: Still holding out for “The Big Day”, the day we can take the small boats out again. If it doesn’t happen, I will be happy for the experience I had on the Gordon Gunter. Sure would be awesome, though…