Sea State: 6-10 foot seas
Sea Surface Tempeature: 42 F
Around 3:00 this morning I heard the engines changing as we came to a station. They were able to quickly squeeze in the CTDA research tool that is submerged in the water to measure conductivity (salinity), temperature, and depth. and a sediment grab, but since then it has been too rough. As I write this we are crossing the northern end of the Bering Strait. It is too rough to deploy equipment, but we are still able to collect data about the surface water, and use the Acoustic Doppler Current Profiler to measure the currents throughout the whole water column. Any water entering the Arctic Ocean from the Pacific Ocean must travel through the strait, so we will make a zigzag path southward to collect as much data as we can.
There is an eight-foot by ten-foot aluminum box strapped to the upper deck of the Norseman II. Its four windows have been blacked out. Inside, the lights are sometimes blood red and sometimes flicker. Is it a haunted house? No, it is a science lab. Inside, Dave, Nate, and Evie are hard at work answering pressing questions about HABs in the Arctic.
Nobody knows how quickly Alexandrium cysts in the Chukchi sea germinate. Without knowing this, we have no idea how dangerous the cysts beds are. This is an important thing to know because it will help the researchers predict the timing and size of Alexandrium blooms, so that they can let local communities know. Dave and Nate are on a quest to find out. But how do you measure a microscopic process taking place on the seafloor?
At several locations, Dave and Nate used the multicore to collect many sediment cores. They transferred the sediment from the cores into clear tubes called PlanktonPlankton are small or microscopic organisms that float or drift in fresh or salt water, especially at or near the surface, and serve as food for fish and other larger organisms. Emergence Traps (PETs) and stored them in an incubator set to the same chilly temperature as the seafloor. Each day, they siphon out the water above the sediment. They filter the plankton out of this water and preserve it in a test tube with iodine. Then they replace the old water with new seawater that had all of the plankton filtered out. Back at the lab in Woods Hole, Nate will count the Alexandrium in each day’s water. This will tell them how many cysts germinated each day.
In 2019, researchers measured the amount of saxitoxin in 7 species of benthic clams in northern Alaska. They found the most toxin in a small clam called Macoma calcarea, an important food source for walrus. An important question for the health of walruses and the humans who hunt them is how quickly the clams can expel saxitoxin from their system. In other words, after a bloom, how soon will it be safe to eat these clams? Evie is investigating this question in the van.
Early Thursday morning, we stopped at station DBO3-8 and took 5 Smith-McIntyre grabs in a row, completely filling one cooler and three five-gallon buckets with mud. Patrick, Evie, and I sifted through the mud to find over 170 Macoma clams. Evie then put the clams in containers filled with seawater that has had all the Alexandrium plankton filtered out of it and put them in a refrigerator so that it would feel like the chilly seafloor temperatures the clams are used to. Every day, she freezes one clam from each container. Back at the lab, she will measure the amount of saxitoxin in each clam. This will give her a sense of how much saxitoxin the clams lose over time.
The exciting thing about this project is that it completely unplanned. Sea iceThere are terms for different types of ice. Shorefast ice forms along coasts and is attached to land. Pack ice is ice floating in open water. Multiyear ice is ice that has survived at least 1 summer. First year ice is ice that has not yet survived a melting season. forced us to turn around early from the Beaufort SeaThe Beaufort Sea lies to the north of Alaska and the Yukon and Northwest Territories., giving us some extra time in the Chukchi. Evie had this experiment in the back of her mind, and when she realized we had more time, she seized the opportunity to set it up.
Who's Who on the Norseman II?
Miguel boarded the Norseman II on July 11th in Homer, AK. On August 15, the crew, many of the scientists, and I will disembark and return to life on land, while a new team boards the ship to return to the Chukchi Sea for Leg 2. Miguel is staying on for Leg 2, which will last until September 6th. By the end of Leg 2, Miguel will have spent nearly two months at sea.
All this sea time is fueled by a passion for understanding how carbon and other nutrients cycle through the Bering and Chukchi Seas (this branch of science is called biogeochemistry). Miguel is a professor of oceanography at Oregon State University, where he teaches classes and runs a science lab. He has been on more than 50 research cruises throughout his career. Onboard the Norseman II, he is in charge of the biogeochemistry research. He collects water samples from the Niskin bottles, processes his water samples for particles and dissolved nutrients, and maintains the underway water sampling system. He has done all of this on his own during leg one, which means he has had very little sleep. He is excited for leg 2, when he will be joined by several students who will help him out.