Costa Rican Dome

In Nicaraguan waters is a regular spring upwelling event sometimes referred to as the Costa Rican dome. Winds blow across the Central American Isthmus near Lake Nicaragua and contribute to an upwelling of nutrient rich waters. These nutrients enable phytoplankton to grow, and as we approach the southern end of Nicaragua, the water takes on a greenish hue, and we note large amounts of sea turtles on the surface of the water.

The turtles don’t seem to pay us much attention as we stop and take a sample. At 11 meters is a thick band of chlorophyll, and the oxygen saturation at the surface of the ocean is 117%, indicating very active photosynthesis (and production of oxygen). As before, we take samples from the oxygen minimum layer and the chlorophyll max. From what I understand, this bloom has only been detected by satellite, and we are the first research group to take genomic samples from this important phytoplankton bloom.