Seasons Come and Seasons Go
With one field season complete and the data finally reviewed, it's time to get moving to put together the equipment we will need for the next field season. This project is built on two large research cruises, the first having been completed in 2017, and the next occurring in late-summer of 2019. For the researchers working on the data from the net sampling, this means 2018 is just more time to work on the 2017 samples, prepare of 2019 samples, and of course, work on the many other projects they are all involved in. But for those of us with moorings, 2018 is not a year off from the field program, but a crucial summer with an action-packed cruise where we will recover and then redeploy the moorings.
The acoustic moorings that I work with are called DAFT moorings, an acronym for Directional Acoustic Fish Tracking. The main instrument on the mooring, which sits on the seafloor and collects data on the water above it, is called a WBAT, yet another acronym, meaning Wide Band Autonomous Echosounder. The instrument, made by Kongsberg Maritime, is a battery-operated echosounder, which produces sound into the water column and measures the echo that is returned. There are two key reasons we need to recover the moorings this coming summer:
In order to collect samples as frequently as we would like, it means we will use up most of the battery during the first year of the two year program (the moorings will be recovered for good during the large 2019 field program). In case they could not be recovered, the instruments are programmed to continue to sample for an entire second year but at much more sparse intervals with the little battery they will have left. However, changing the batteries this summer will ensure that we will get equivalent data from 2018-2019 as we did from 2017-2018.
I have no idea what the moorings are seeing! All of the data collected by the echosounders are stored inside of the housing on a very large (and very fast) USB thumb drive. In order to see the data, we have to get the moorings back. By recovering them this summer, we can check if there were any issues and make the necessary adjustments for the second year.
Instead of being part of a large fisheries survey this summer, I will be working with the NOAA Pacific Marine Environmental Lab who go to the Arctic every year to do this type of mooring turnaround work. We will be working on the USCGC Healy, one of the US icebreakers, as just one component of much larger oceanographic research cruise.
So as we head into spring, I'll be back at work, building a spare mooring (fingers-crossed, but spare parts are always a necessity).