Multi-corer Muddiness

Four people on deck – two holding tag lines, two steadying the multi-corer and waiting to pull out the safely pins – prepare the multi-corer for deployment. With the coring tubes prepped, the multi-corer is lifted from the ship’s A-frame, hovering, swaying slightly back and forth. Over the water, it is lowered slowly to the surface, through the water, and down to the bottom – a depth of only about 50 m in the Chukchi Sea. While we are waiting, we make bets on how much mud we will find today. My favorite was when Paul, the Bosun, guessed we were going to catch only a crab and no mud – surprisingly, he was right! When the multi-corer reaches the bottom, the tension from the cable releases, and the lead weights plunge the coring tubes into the sediment. When the multi-corer is lifted again, the caps spring shut, capturing the sediment and bottom water.

Once the multi-corer is back on board, the science team leans in to inspect each core, oohing and awing at the visible benthic critters – clams and worms burrowing through the sediment. We don’t have too much time to admire the lively benthic community we’ve recovered, however, because we need to remove the full cores, reload the multi-corer with new ones and prepare for redeployment. We’ve had a tight science schedule on the cruise, and 3 multi-corer deployments and the bottom trawl are what stand between us and the transit to the next station.

After inspection, my adviser, Dr. Sarah Hardy, designates each core for a specific sampling purpose, and we get to work. The coring tubes are 10 cm wide and 70 cm long. Some cores are sub-cored with a smaller tube for respiration experiments of the whole sediment community. Others are sliced at certain depth intervals and frozen for later processing to identify, count, and weigh meiofauna and macrofauna back at the lab in Fairbanks. We are also sampling cores for chlorophyll-a, microbial DNA, and bioturbation rates. It’s amazing how much information you can collect about the structure and function of the benthic community from a tube of mud!

It’s not easy work, however. By the end of the day, the coring crew is covered in mud from head to toe (not an exaggeration), exhausted from a long day of strenuous labor. Other than the first few days, I have been spending the majority of my time in the cold room running respiration experiments. So, I have not been able to help with coring as much as I would like...it’s not every day you get to experience an Arctic-clay facial on the deck of the Sikuliaq!

#sediment #mud #multicorer #Sikuliaq #ASGARD #benthic