March 17, 2009
Sea temperature: 0.077 °C
Air temperature: 0.6 °C
Well before the sun came up this morning, Ron Kaufmann’s team assembled on the back deck to recover the MOCNESS 10m2 net system that had been towed behind the ship for the past six hours. The aft A-frame lifted the large and heavy nets and the team, led by the marine tech duo on watch, handled tag lines and maneuvered nets onto the deck.
The scientists eagerly opened each net’s cod end, a grey plastic cylinder that traps the organisms at the rear end of the net. The cod ends were washed with seawater into numbered buckets corresponding to the net in which they were collected. This separation will become important later when net contents are analyzed with oceanographic parameters that were recorded at the same time.
As we peered into the buckets, it was exciting to see the many different species represented. The buckets contained Antarctic krill, salps, jellies, polychaete worms, siphonophores, ctenophores, a few fish, and even some very small squid. All were transferred to temporary storage in the cold room where the buckets stayed until the samples were sorted.
Then the real fun began. Onlookers from the different science groups came by to see what the nets had caught. In assembly line fashion, Kaufmann’s team used long forceps to sort the critters into smaller beakers. The goal was to separate each organism to the most specific taxonomy as possible, sorting to species at best (for example, Antarctic krill is Euphausia superba) or at least to class (for example, an unidentifiable medusa jelly might just be Class Scyphozoa). The team worked all day and is still not done at nearly nine o’clock tonight.
Some are using dissecting microscopes to further identify mystery organisms, counting distinguishing body parts, drawing sketches, and comparing these to a library of reference materials they brought onboard. Once samples were sorted, the individuals in each group were counted, weighed, and recorded. Some were frozen for later analysis, while others were preserved for future study.
Science is literally happening around the clock now that weather and equipment are cooperating. Since this MOCNESS deployment last night, we’ve had more CTD bottle casts, an ROV dive to the iceberg, and shallow towfish water collections. All the lab areas are busy processing samples before the next round of sampling repeats tomorrow.
Now it’s after 10 pm and the rain showers that kept us wet during ROV IceCUBE’s dive have turned to a damp, heavy snow. The flurries are swirling around the back deck as the MOCNESS pre-dive tests are underway before it goes back into the water for another night of fishing.
—Debbie Nail Meyer