Escanaba Trough Expedition: Part 3 (AD)
For scientists aboard the Escanaba Trough expedition, obtaining sediment cores or deep-sea biological and geological samples after a Jason dive is only the beginning.
Samples from the seafloor can be chemically unstable at the surface. Many hydrothermal fluids and minerals rapidly oxidize after contact with air, so care must be taken to process samples as quickly as possible.
Deep-sea biological samples such as corals, sponges, crustaceans, echinoderms, and microbes are often sensitive as well, requiring proper handling under climate-controlled conditions.
Measuring trace metals in water samples from conductivity, temperature, and depth (CTD) casts is especially tricky, as the samples can be contaminated by ever-present metal ions in the environment.
Sediment cores require quick processing to preserve nutrients in the surrounding pore waters and the animals, microbes, and organic compounds within the sediment. Caution is required to avoid contamination, as invisible microbes and organic compounds are everywhere, including on most surfaces, researchers’ hands, and even on their breath!
In most cases, samples can be stowed away for more in-depth analysis back on shore. Accurate labeling ensures that samples can be cross-referenced with dive charts to determine where and at what depth the sample was collected.
Music: “Ramo” by Valante, used with permission from Epidemic Sound