Flexibility is key!
Day 9 – 10 January 2023
The day began with a plan to visit an Adélie penguin colony, but the weather wasn’t cooperative. Instead, we went out with the science team for a Zodiac cruise around Gerard Bay to drop a Secchi disk and trawl for phytoplankton.
The Secchi disk is a 30cm white disk that is slowly lowered over the side of watercraft to measure the turbidity of the water. Turbidity is important to measure because it is an indication of how much ‘stuff’ is in the water. If the water has many things in it, like phytoplankton or sediment for example, the disk will be quickly obscured. If the water is very clear, the disk will still be visible at greater depths. On this science cruise, the Secchi disk disappeared for our observer at 9 meters depth.
Chris and Anjali dropping the Secchi disk and handling the plankton net (photos by Kat)
In addition to how much phytoplankton is estimated to be in the water, we also took a sample of the water to determine which species of phytoplankton were present. To do this, a jar is attached to a funnel shaped sieve and dragged behind the boat for a short distance. Once the equipment is back on board, the sieve is replaced with the lid to the jar to preserve the sample to examine later. It proved a little tricky to tow the plankton net from our zodiacs as strong winds whisked up the sea and floating brash ice from the nearby glacier covered the surface.
An unexpected but very welcomed surprise arrived by zodiac in the form of our expedition leader Fred and his assistant engaged in boozy hot chocolate deliveries! The cold, wet, and blustery conditions were greatly improved by the delicious (and still warm!) beverage. The arrival of four graceful snow petrels diving in and around the icebergs wrapped up our last day off the Antarctic Peninsula and our memories of Gerard Bay.
Once the Zodiacs were back on board the ship, we headed north for our second crossing of the Drake Passage. We understood very quickly why the weather canceled our plans to go by the South Shetland Islands because we immediately hit the kind of swells that sends everyone to their cabins for a while.
Written by Kathryne
