Life is Controlled by the Limiting Nutrient

Incubation Experiment

We all know that we are supposed to eat a balanced diet containing the Recommended Dietary Allowance of vitamins and minerals to maintain our health.  Humans, and all other organisms, require major and minor nutrients in well-defined quantities for healthy growth.   Marine phytoplankton, free floating marine plants, harvest the energy of the sun to fuel their growth, but they still need nutrients as the building blocks of their new cells.   The basic building blocks for marine plankton are carbon dioxide, water, nitrate, and phosphate.   The ocean generally has plenty of water and carbon dioxide, but can often be depleted in nitrate or phosphate.   If we think about photosynthesis as a balanced chemical reaction it is easy to use chemical stoichiometry to understand this limitation, Continue reading

Posted in All, Science, Uncategorized | Comments Off on Life is Controlled by the Limiting Nutrient


Searching for penguins

Saturday marked the halfway point of our cruise.  In two more days we’ll be at the southernmost station of our trip, and then we’ll alter our course onto a two-week long diagonal towards South Africa, our ultimate destination.  We have left the warm weather behind us, and are now in weather more comparable to that that which friends and family at home in the Northeast are currently experiencing.  Temperatures are around 40˚F (so it’s a bit warmer than Maine) and the sky has mostly been gray and overcast with occasional showers. Continue reading

Posted in Uncategorized | Comments Off on Halfway

Wildlife Sightings

While we’ve been at sea, we haven’t spotted too many organisms other than those that can be seen using a microscope.  However, in the past few days we’ve sighted several new species!  On Sunday the crew set up three lured fishing lines off the stern.  These lines don’t require constant attention, only occasional checks to see if they’ve hooked anything.  One of these lines caught a beautiful yellowfin tuna!  Although I’m not usually a big fan of raw fish, I decided to try this fish at dinner, and I was glad I did.  It melted in my mouth…nothing like fresh sushi! Continue reading

Posted in All, People, Ship, Uncategorized | Comments Off on Wildlife Sightings