A time-series of iron and other micronutrients at Station ALOHA!

Sailing on the R/V Kilo Moana

Profiling the water column

How much iron sinks below the surface?

The Hawaii Ocean Time-series program travels to Station ALOHA several times a year. Over the next few years we will be tagging along to measure how iron, manganese and other metals vary over the seasonal cycle, and how quickly these micronutrients cycle through the ocean.

Recent measurements have suggested that humans contribute a large source of iron to the atmosphere, that then falls on the ocean. Our time series observations will determine how this anthropogenic source compares to the natural processes that add iron to the oceans, such as deposition of desert dust.

This project is led by Ph.D. student Eleanor Bates , who presented this work at Ocean Sciences 2022 and the 2022 Goldschmidt Conference.

Exploring the ocean's cobalt cycle

Of all the elements required for life, cobalt is found at the lowest concentrations in the oceans. As a result, we're still learning about its sources and sinks, and how phytoplankton acquire cobalt from seawater.

Building off of mapping efforts conducting by the GEOTRACES program, we are expanding the coverage of cobalt measurements across the globe to identify hotspots of cobalt sources to the ocean.

This project is being led by UHM Undergraduate Researcher Stephanie Briones.

Investigating micronutrient limitation with cultures, models, and natural gradients

There's more iron in a drop of blood than in a ton of seawater, but life in the oceans still requires iron, and many other scarce metals, to grow.

Phytoplankton and other microbes have evolved to minimize these requirements, but no one has figured out how to replace the crucial roles of iron in photosynthesis and respiration.

By growing key phytoplankton in the lab, we can figure out how much iron they need and assess if they can survive in harsh marine environments where iron is lowest. New Ph.D. student Megha Rudresh will soon begin conducting these culture experiments.

We are recruiting postdocs to develop new methods to quantify micronutrient limitation in natural phytoplankton populations. Please consider submitting an application here. Youʻll need to look up Position # 222469.

Email with any questions.