I’m going to be honest, it’s been a very long couple of days. My body no longer has much sense of time, which I guess is kind of a good thing given what I’ve been asking of it (and will continue to ask of it for at least another week). My lab-mate Craig and I started sampling at 12:30am on Friday morning and we worked until 7am collecting samplings of bacterial DNA to analyze back in the lab at UBC, then took a quick nap until 9am when we had to be back up for a second bout of sampling that would last until around 5pm Friday night. This one was going to be REALLY important because I was trying a new incubation experiment I’ve never done before to try and measure the rate of bacterial denitrification in the deep (~1000m), low oxygen waters of the Subarctic Northeast Pacific Ocean (saNEPac!).
Denitrification is generally an anaerobic process (meaning it only occurs in the absence of oxygen) that bacteria use to obtain energy by converting nitrate (a very abundant nutrient in the oceans) into nitrogen gas (N2). One of the reasons we are interested in this process is because nitrogen gas is not biologically available for organisms to take up and use in their cells, so bacterial denitrification effectively reduces the amount of nitrogen available to living organisms in the ocean. Secondly, denitrification is a stepwise processes and the 3rd product in the process happens to be the climate active greenhouse gas, nitrous oxide. We have observed that nitrous oxide is being produced in the deep waters of the oxygen minimum zone (500-2000m) in the saNEPac, and I have been curious to find out whether or nitrous oxide is being produced via denitrification, or via some other process. Because there are still low amounts of oxygen in the water column here, many marine biologists believe that the nitrous oxide could not possibly be being produced by denitrification, but the only way to confirm that for sure is to check! The first step was to test for the presence of denitrification, using a fairly complex incubation experiment that involves adding several stable isotopes of nitrate, nitrite, and ammonia, which would allow us to trace the production of nitrous oxide. I’ve been training and prepping for this experiment for almost a month, so needless to say, the pressure was on!
Things were going fairly well by 11:30am – we’d made it through our first 3 sets of incubations (out of 6) when something when awry… the specialized tank of blended helium and oxygen I was using to bubble the samples and remove atmospheric nitrogen ran dry!! Luckily I had a backup tank on-hand, but was not sure if this tank would last me for my next set of incubations I had prepared for at Station Papa! I had also completely not planned for the event of running out of gas – my colleagues and I had expected I wouldn’t even use one whole tank for the entire cruise, so I was sent into a bit of a whirlwind of damage control trying to figure out what had gone wrong. Had the tank been leaking? Was I using too much gas? But this was no time to be distracted – I had to keep going with the task at hand. We managed to finish all the incubations with the new tank of gas and kill the time zero (t0) samples by adding mercury chloride to kill the bacteria and give us a background reading of nitrogen products before we gave them time to start (potentially) producing nitrous oxide.
After the incubations, we had to attend to some other measurements that had been put on hold in the meantime. We had taken samples to measure nitrite and ammonia concentrations in the water column which had been incubating with reagents that cause them to change colour depending on how much nitrite/ammonia are present and the samples needed to be quantified on the spectrophotometer (which reads fluorescence). Much to our horror, we realized that the nitrite standards were WAY too dark – meaning Craig had accidentally used the concentrated stock instead of the diluted stock to make the standards. To make matters worse, the samples were reading negative values on the spec! We madly sent out some emails to our contacts back on land for advice, and it turns out that the nitrite samples have to be read within 2 hours of having the reagents added – a very important detail that hadn’t been recorded in our version of the protocol!
Needless to say, at this point I was starting to feel pretty discouraged and upset, regardless of the lack of sleep and proper meals. I was angry at myself for not having checked the nitrite protocol more carefully before having left for sea, and was disappointed that all my careful preparation for the nitrogen incubations might be lost to something as trivial as running out of gas – a setback I had simply not anticipated or prepared for!
After sleeping from 7pm until almost 6am this morning, I was feeling marginally better but still pretty down. Making mistakes and having things go in ways you hadn’t anticipated is often part of science, but somehow still always leaves me questioning my own abilities and dwelling in the past, at least for a little while. The turning point in my day was an email from my best friend (and one of my greatest mentors) offering some wise advise about how to approach my current dilemmas. He said:
“Sometimes in life we have to be like a world-class goaltender. You can’t be your best in the rest of the game if you keep thinking about the one puck you let in. You have to forget about that goal that was scored on you and focus on keeping the rest of the shots out of your net.”
I smiled a huge smile as I read this and realized how right he is – the only thing focusing on mistakes usually brings us is more unwanted mistakes. And just as this is my 6th trip to Station Papa and I feel like I should be too experienced to make mistakes, I’m sure that even the best goaltenders still have a bad game once in a while even after 30 years of playing the game. So I’m heading into another station of sampling keeping my stick on the ice and focusing on keeping the rest of the shots out of the net. I’m just know this one can be a shut out.