For me, oceanography is a place for romantics that hope to change the world with colossal discovery and reach out to a vast and foreign ocean. I think every scientist has a romantic side, whether it’s a life-saving pharmaceutical, ecosystem-saving data, or technology that wows and inspires. However, my chemistry friends in Georgia would never have seen a 50-foot whale taking a breath and waving a massive tail…while relaxing on deck…at sunset…romantic.
My responsibilities aboard the Melville primarily involved measuring oxygen and calcium in the water from the surface down to the last 1,000+ meters. For both oxygen and calcium, we carefully collected water samples from bottles that were opened at various depths in the water column.
Oxygen Background/Details: Oxygen was measured via Winkler titration with a custom-built titration cell and computer program. Almost all chemical measurements are first developed as a lab-based “bench top” method before advancing to a sensor. The CTD rosette aboard the Melville was equipped with an oxygen sensor, but needed calibration to improve accuracy. Since oxygen is one of the most universally important measurements of biological activity, a dissolved oxygen titration, known as a Winkler titration, was developed in 1888.
I developed a similar titration cell and computer program for calcium measurements over the last few months. The samples that were taken from the water column and overlying bottom water on this cruise will provide both a test of the measurement system and calcium source/sink hypotheses.
Calcium Background/Details: Calcium carbonate is used for shells and other hard parts of ocean organisms. In areas like coral reefs where calcium carbonate formation is abundant, the level of formation is termed calcification rate. The dissolving of the calcium carbonate biominerals is called dissolution rate, which is mediated by both physical and chemical parameters such as depth, temperature, pH, and carbonate concentration. As carbon dioxide continues to increase the acidity of the ocean, many researchers are focused on the possible impacts to calcification and dissolution rates in the ocean. Calcium carbonate is also a major source/sink of inorganic carbon in the long-term ocean budget; therefore an accurate and precise measure of calcium can provide relevant carbon budget information.
I certainly spent most of my time on board the Melville doing important science, but it’s equally important to mention some of the awesome people, food, and experiences in between. In no particular order: overlooking the Pacific, daily murals by resident artist and fun person Lily, kudu and ostrich dinner, headphone speakers arranged to provide the ultimate in surround sound, a live video feed of the ocean floor, portholes in the front of the ship providing a submarine experience (Life Aquatic anyone), and an overall great group of people.
I’m not sure how that sounded to you, but being at the forefront of scientific knowledge and inventing instruments while floating in an endless sea with giant whales and mud murals of ancient microscopic bugs sounds romantic in every sense of the word to me.
-- John Ballard, Scripps Graduate Student