Depth: 84.64 feet (25.8 meters)

    Sea Surface Temperature: 48 F

    Upcoming live PolarConnect event from the Chukchi Sea!

    On August 4th I will be hosting a live zoom from the Norseman II! You can tune in to learn about the research, see some benthic organisms, check out Alexandrium and other plankton, and meet some of the scientists!

    It will be at 9:00 AM Alaska Time/ 10:00 AM Pacific Time / 11:00 AM Mountain Time / 12:00 PM Central Time / 1:00 PM Eastern Time. I would love for you to join!

    You can register at: https://www.polartrec.com/polar-connect/register

    The Fast and The Furious

    Before today, all of our stations were at the relaxed pace of one station, followed by an hour’s travel to the next spot. This gave us more than enough time to process samples, prepare for the next station, and even grab a snack. Today was a different story. The Bering Strait acts as a bottleneck between the Pacific and Arctic Oceans. Any water or plankton travelling from the Pacific to the Arctic must travel through this narrow gateway, so we wanted to squeeze in as many samples as possible in order to get a clear picture of who is travelling through and where they are coming from.

    sea urchins
    Our sediment grab in the Bering Strait was full of sea urchins!

    The result? Our stations were only 20 minutes apart. It was a wild scramble to collect all the water samples from the CTDA research tool that is submerged in the water to measure conductivity (salinity), temperature, and depth. in time to set it up for the next station.

    The water was glassy calm, and seabirds flew around us. Little by little, Inalik (Little Diomede) grew closer until we were 1.5 miles from the steep cliffs. Big Diomede peeked out of the fog only 3 miles away.

    Little Diomede
    Thousands of seabirds flew around Little Diomede.

    Common murres
    Common murres eat fish and have been known to dive more than 500 feet underwater.

    Being so close to Russia was very interesting. My phone somehow picked up a Russian signal and set itself to a Russian time zone, 20 hours ahead of Alaska time. I keep forgetting about that, glancing at my phone to see what time it is, and then getting confused.

    We finished the rapid-fire Bering Strait transect line by lunchtime. In the early afternoon, we steamed to our fourth line, Bering Strait North, which runs from near the International Date Line to the coast of the Seward Peninsula near Shishmaref. While I was filtering water from the first station, captain Casey came on the intercom to announce that we had crossed the Arctic Circle!

    Today was definitely interesting for a geography nerd such as myself.

    Wales
    Leaving North America Behind. The village of Wales got smaller and smaller in the distance as we traveled west across the Bering Strait.

    Introducing Alexandrium

    We are studying Alexandrium because it produces saxitoxin, the chemical that causes paralytic shellfish poisoning. The name Alexandrium actually refers to a group of plankton. On this cruise, we are studying a specific species called Alexandrium catenella. However, to keep things simple, I’ll just say Alexandrium.

    alexandrium
    The IFCB took this photo of an Alexandrium cell.

    Alexandrium is a phytoplankton, meaning it uses sunlight to make energy.

    It has a unique lifestyle. It starts its life as a cyst, a small seed-like particle that lives in the seafloor sediment. In the right conditions, the cyst germinates into an Alexandrium planktonic cell swimming in the water column. The plankton can replicate itself through cell division, and the duplicates eventually reproduce, creating more cysts. The cysts can survive harsh conditions that would kill an Alexandrium in its planktonic state.

    Alexandrium life cycle
    Alexandrium has a unique life cycle. Each cell starts as a cyst in the mud, then germinates into an algal cell swimming in the water.

    Introducing Pseudo-nitzschia

    Pseudo-nitzschia is also a group of phytoplankton. There are 15 or so species of pseudo-nitzschia in northern Alaska. Many of them look very similar, and can only be told about by looking at their DNA.

    Some species of Pseudo-nitzschia produce domoic acid, the toxin that causes amnesiac shellfish poisoning. Unlike Alexandrium, Pseudo-nitzschia spends its entire life as a planktonic cell.

    pseudo-nitzschia
    The IFCB took this photo of three Pseudo-nitzschia cells. "Pseuds" often link up in chains like this.

    Date
    Weather Summary
    Calm. Foggy in the morning, sunny later on.
    Temperature
    39 F
    Wind Chill
    39 F

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