31 July 2022 A Bucket of Toxins

Journal

Sea Surface Temperature: 47 F Wave Height: 6 Feet

Storm Delay and Point Hope

When I came up to the lab this morning, almost the entire 12:00 AM-12:00 PM shift was asleep on the sofa and the boat was rocking in large swells. What the heck was going on? I hunted around till I found I found Jei taking advantage of the quiet to get some work done. He told me that operations were on hold until the sea settled down.

Luckily at 7:00 AM the sea was less rough and we were able to start back up. This line took us very close to Point Hope. Because the Norseman II is much smaller than the boats usually used for this research, we were able to make measurements close enough to shore to see people driving four wheelers on the beach.

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. Tow

Today Nate showed me how to collect plankton with the plankton tow. The official goals of collecting the plankton is to find out what HAB toxins are in the water and what plankton live where.

plankton tow prep — We have to attached a heavy weight to the line to make sure the tow goes straight down. As you can see, the weight is made out of three shackels and a dumbbell.

Plankton tow deployed — The tow is dropped straight down in the water for 30 meters (99 feet). As it is lifted back up to the ship, it captures all the plankton in its path.

After we brought the plankton aboard the ship, the real work began. Nate showed me how to prepare the plankton for storage and transport back to the lab in Woods Hole. Each vial of plankton has to be prepared in a different way for each type of analysis that it will undergo, and all of the vials are then stored in a freezer. Some of the plankton will be analyzed for toxins, and other plankton will be analyzed for DNA.

Toxin Analysis

One important question is what toxins are in the water. The plankton will be analyzed back at the lab for three types of toxin:

Saxitoxin- the neurotoxin produced by Alexandrium. Saxitoxin can cause paralytic shellfish poisoning.
Lipophilic Toxins - these are toxins that can be stored in fat tissues. A variety of plankton can produce these. These toxins are concerning because they could be stored in walrus blubber, potentially affecting anyone who eats the blubber.
Domoic Acid – the toxin produced by Pseudo-nitzschia. It causes amnesiac shellfish poisoning.

The toxins in the plankton sample we collect will be compared to the toxins we find in the benthic organisms we are collecting to see if the amount of toxin in the water matches the amount of toxin in the benthic community. This will help us understand how the toxin moves through the food chain.

A tube of plankton ready to be analyzed for domoic acid.

DNA Analysis

Back at the lab, the DNA will be extracted from the plankton cells. From the DNA, Evie and other researchers can identify what plankton species are present in the water. They can also compare the DNA from different tows to see what species live where. This can help them answer questions like, “Do the same plankton live near Nome as live near Utqiagvik?”