Every year in the late summer, the waters north of the Hawaiian Islands transform. This transformation is marked by the appearance of a vibrant diatom bloom—a burst of life in an otherwise nutrient-scarce region. Diatoms, tiny, single-celled organisms encased in glass-like silica shells, thrive in these conditions, multiplying rapidly and forming vast underwater “clouds” that can stretch for miles.
This transformation is usually invisible to the naked eye, but satellites can detect the subtle changes. The movie below shows the changes in chlorophyll – the pigment that captures light for photosynthesis – during the month of August. The satellite data shows the change from low chlorophyll (blue colors) to high chlorophyll (yellow colors) over the course of the month. The changes are beautiful and dramatic over the course of just weeks.
We have the special opportunity to sample during this ‘bloom’ period. Our sampling, which is west of the red dot and in the area north of Kauai has seen a dramatic increase and decrease in chlorophyll intensity. We happen to be sampling this water during what appears to the be decline of this ‘bloom’.
This dying diatom bloom is a crucial event in the marine ecosystem. It represents a significant transfer of carbon and nutrients from the surface to the deep sea, playing a key role in the ocean’s biological carbon pump. The material generated by diatoms and other phytoplankton sinks and becomes a rich source of food for deep-sea organisms and contributes to long-term carbon storage, helping to regulate the Earth’s climate.
Sampling a dying diatom bloom provides a rare opportunity to observe these processes in action. I am particularly interested to see if viruses might be involved in the death of the phytoplankton during this bloom. By understanding how these blooms decay and the factors that influence their lifecycle, we can gain insights into broader oceanographic and climatic phenomena. It’s a chance to witness the delicate balance of life and death in the ocean and to appreciate the complex mechanisms that keep our planet’s ecosystems in check.