With 2 of 8 weeks behind us and 10 of 35 stations completed, people are starting to feel the effects of long hours and the physically demanding work of being an oceanographer. People are getting very good at napping when they get the chance, including in the computer lab from where the carousel and rosette bottles are fired!
Here are Laura and Rob dozing off the other morning…
And Sara who impressed us by sleep-planking!
Together with Claire and Greg (seen on a ladder in the last post), the 6 of us are responsible for deployment, recovery, and sampling from Carlson, the GEOTRACES carousel.
What makes our jobs unique?
We are responsible for collecting samples for ~16 groups analyzing ~25 “trace metals” and a few other elements. Trace refers to the ultra-low concentration of various metals from the periodic table (like iron: Fe and lead: Pb). Due to the very low concentrations, contamination of these seawater samples is a major concern. Most oceanographic sampling devices have metal components in them, which are in direct contact with the seawater samples. If we collected samples with this type of equipment our concentrations would be falsely too high. Instead, metals parts have been replaced with Teflon and plastic ones. When we sample the seawater, it is done in our clean lab, where nearly entirely plastic (except for the door hinges and fire extinguisher). We also take extreme care to not bring in dirt from the deck by kicking off our shoes outside and stepping in barefoot, and keeping our clothing free from dust, grease, and other particles. Claire and I are responsible for collecting seawater for 12 groups from our GoFlo bottles, and our official job titles are SuperTechs. Rob, Sara, and Laura are in charge of filtering water for small particles (like dust globs and plankton) for 2 groups, and collecting a few water samples for 4 other groups. Greg is responsible for our group and drives the winch that lowers Carlson up and down in the ocean.
Why care about elements in such low concentrations?
There are several reasons. For people who study iron, despite the very low concentrations present in seawater it still has a huge impact on the small photosynthetic plants (phytoplankton) that grow in the ocean. In some places, it is the “limiting reagent” for their growth – which means they have plenty of the other nutrients but not enough iron to grow. This is like wanting to bake cookies with a recipe that uses 3 eggs, and you have plenty of flour, butter, and sugar but only 2 eggs. Your batch is scaled back by 2/3 unless you find more eggs.
Another reason is that pollutants like lead are diluted by the wind that transports them and huge volumes of seawater. Remember that the Earth is over 70% water! While a pollutant isn’t in extremely high concentrations in the middle of an ocean, contamination sources are still pumping out potentially harmful quantities on a yearly basis.
Does all this worry about contamination affect what you wear in a clean room style lab?
Yes and no.
No: We aren’t too concerned about metal from our watches or glasses frames or even wedding rings contaminating the samples – because these things should never end up in our sample bottles or even touch their outsides (we wear gloves, and don’t rub our faces on them!) We have had a request from the girls analyzing mercury (Hg) not to eat tuna around their samples (these fish are notorious for their high Hg content) or breathe heavily on their sample bottles if we have fillings (the traditional metallic ones are an amalgam – which means a mix of metals – that usually includes Hg which is released into your saliva and breath).
Yes: Cheaper metals like the little rods holding your watchband to its body, zippers on clothing, and cheaper jewelry rust really easily when exposed to seawater for hours each day. We can’t have rusty things in the lab, and we also don’t want to have our personal items destroyed. For this reason, many of us minimize the metal on our personal belongings that we bring in with us.
Does all this worry about contamination affect what you wear in a clean room style lab?
Yes and no.
No: We aren’t too concerned about metal from our watches or glasses frames or even wedding rings contaminating the samples – because these things should never end up in our sample bottles or even touch their outsides (we wear gloves, and don’t rub our faces on them!) We have had a request from the girls analyzing mercury (Hg) not to eat tuna around their samples (these fish are notorious for their high Hg content) or breathe heavily on their sample bottles if we have fillings (the traditional metallic ones are an amalgam – which means a mix of metals – that usually includes Hg which is released into your saliva and breath).
Yes: Cheaper metals like the little rods holding your watchband to its body, zippers on clothing, and cheaper jewelry rust really easily when exposed to seawater for hours each day. We can’t have rusty things in the lab, and we also don’t want to have our personal items destroyed. For this reason, many of us minimize the metal on our personal belongings that we bring in with us.
The weather is slowly warming up. Everyone envisioned the South Pacific much like the posters to the musical of that namesake. That was a major oops on our part! The number of hot and sunny hours to date can be counted on 1 hand. This should improve greatly as we head further offshore into warmer waters (today we’re at 12°S, 95°W).
Claire enjoying the fleeting sun on the ship’s bow last Friday.
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