The ocean is so blue

So blau ist das Meer mitten im Pazifik!
This is the blue of the Pacific Ocean!

We are now in the middle of the ocean, surrounded by blue water. And finally we have also collected our first samples. That was a very exciting moment: the Niskin bottles (water samplers) came on board for the first time with our eagerly-anticipated water.

What a color! It is hard to describe this type of blue, perhaps ‘crystal blue’, if that is a useful description. We are from land, so there are few particles in the water that could make it cloudy, there are no rivers in the region that could dump their load of particles into the ocean. In this part of the ocean, there are also very few nutrients, so very few phytoplankton (marine plants) grow here. Few particles and few phytoplankton mean that we can see into the deep: we can look down to a depth of 45 meters.

Despite the fact that the water looks blue and clear, it is not just plain water. And also not just plain saltwater: seawater always contains life.

The majority of the organisms it contains, however, are so small that one can’t see them by eye, and even under a microscope, these life forms only look like small dots and rods. For the most part, these dots and rods are bacteria, referred to as ‘microorganisms’ because of their small size.

All of the scientists on board are intensely interested in microorganisms.

How many will we find in the different depths of the ocean, and different regions of the Pacific? Which bacteria are they, and what are they doing?

How do different bacteria live together, how do they divide up their habitat? A major question that we would like to answer is, what do they eat? What is on their menu, and how fast can they find and eat their food?

We are investigating all of these questions. Today we finally had our first water samples. The first station was a “shallow” station – our term for stations in which we “only” collect samples down to a depth of 1000m.

The water from this depth is surprisingly cold, only 5 °C, so it feels as if it came straight out of the refrigerator. Once we collect our samples, the warm tropical air immediately condenses on the surface of our bottles.

Tomorrow we are taking our first “deep” station, one that goes all the way to the bottom of the ocean.