Evie Fachon and her team from the Anderson Lab at the Woods Hole Oceanographic Institute (WHOI) are studying harmful algal blooms (HABs) on this expedition. As the oceans begin to warm and the sea ice melts, algae has access to more light. Algae are photosynthetic organisms and so warmer temperatures and increased sunlight result in more often and longer-lasting algal blooms. More specifically, Evie and her team are looking at the toxic dinoflagellate species Alexandrium catanella. It is one of the species that causes paralytic shellfish poisoning (PSP) and can affect organisms higher up in the food chain, including humans.

Alexadrium from the Chukchi Sea under a microscope.
Alexadrium from the Chukchi Sea under a microscope.
Evie Fachon (WHOI) working on the harmful algal blooms project.
Evie Fachon (WHOI) working on the harmful algal blooms project.

Dinoflagellates, like Alexandrium, are often consumed by filter-feeding bivalves or fish and invertebrate species. These organisms are then eaten by marine mammals and humans. Eating an organism contaminated with toxic algae can cause neurological problems and even death.

A density map of Alexandrium cysts in the Bering and Chukchi Sea. (Natsuike et al. 2017)
A density map of Alexandrium cysts in the Bering and Chukchi Sea. (Natsuike et al. 2017)

One of the interesting things about Alexandrium is that they have cysts that can lay dormant in mud at the bottom of the Arctic. This means that they can overwinter in the Arctic Ocean until conditions become nice enough (warm with light availability) for them to bloom. A paper by Natsuike et al. in 2017 looked at the distribution of cysts for the Alexandrium tamarense, another common species of this algae, in the Bering and Chukchi Seas. The benthic team and Evie have been working together to collect top-layer mud to continue this study and monitor the A. catanella species of this toxic algae.

Dr. Lee Cooper and Kelly Kapsar getting top mud from a Van Veen grab for the harmful algal bloom study on Alexandrium.
Dr. Lee Cooper and Kelly Kapsar getting top mud from a Van Veen grab for the harmful algal bloom study on Alexandrium.

Kelly Kapsar and Nicole Villeneuve were getting water samples in the CTD room today and took a new flag from an Ecology Explorers student from Nome. More flags to follow!

Nicole Villeneuve and Kelly Kapsar holding a flag from the Ecology Explorers program in Nome.
Nicole Villeneuve and Kelly Kapsar holding a flag from the Ecology Explorers program in Nome.

A Question From the Crow's Nest

What are the two most common toxins produced by harmful algal blooms?

Answer from previous post: Gray Whales can eat 1.3 tons in one day.

Date
Coordinates
73° 28' 27" N , 159° 10' 47" E
Location
Chukchi Sea
Weather Summary
Overcast, windy, 1-3 foot waves
Temperature
38 degrees F
Wind Chill
31 degrees F
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Comments

Deanna Wheeler

Hi Piper--
It appears that the algae is migrating North as the water warms. Have the detected the toxic algae in the Arctic Ocean for many years? Is there an optimal temperature range for the bloom as it seems that the blooms are later in the season the farther North you go. Is the bloom migrating or is it just coming out from the mud in the Arctic Ocean?