We actually did some science today and it was pretty exciting. You can tell how eager everyone is to get started because we were all crowded around the instruments and the computer screens even though this was only a test site. The idea behind a test site is to make sure the gear all works and we have our sampling procedures down before we get to the actual site of interest.  If anything had gone wrong with today’s instrument deployments we would have the next 20 hours to make adjustments before we get to the first site within the oxygen minimum zone.

The exciting part of the day for me was that we got to deploy a new device created by my advisor and the cruise’s chief scientist that is designed to filter water and preserve it for RNA at whatever depth you want.  The chief scientist had never seen the instrument in person so I was responsible for giving him and his group the run down, and if things go wrong it falls to me (with help, hopefully) to figure out why.

The traditional way this type of sampling has been done is to collect water in what is called a Nisken bottle at your desired depth, bring the water to the surface, filter it, and then preserve it. This method works fine for DNA because the composition of which microbes are present in the water isn’t going to change much in a few hours. However, RNA is probably a very different story. RNA records what a cell is actually doing (what genes it’s using that moment) where as DNA is a record of all the genes an organisms has, regardless of what it’s doing. RNA is much shorter lived and changes much more frequently. It’s entirely possible that we are not getting an accurate picture of what organisms are doing in the water column when we bring them up from depth (changing their temperature, pressure, light exposure oxygen exposure…) and then preserve samples for RNA analysis. Hopefully the instrument we deployed today (nicknamed the PIMPR or prototype in situ microbial preserver of RNA) will allow us to get a more accurate picture of what these organisms are actually doing when we haven’t disturbed them. The trial run went well after a few initial hiccups. Having to troubleshoot an electronic instrument is a new challenge for me, but so far I’m enjoying it!

Tomorrow we start collecting samples – woohoo!

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