By Thomas Farrugia
Image of the IFCB being set up by Thomas Farrugia in the lab space of the USCGC Healy. Photo by Kali Horn.
This summer, several areas around Alaska recorded levels of paralytic shellfish toxins above the safe limit for human consumption. These toxins, produced by harmful species of phytoplankton, can enter the food web, posing threats to both wildlife and people. Monitoring for harmful algal blooms (HABs) is essential but challenging, particularly in remote regions of Alaska.
In response to this growing concern, the Alaska Ocean Observing System recently purchased an Imaging FlowCytoBot (IFCB) to enhance monitoring capacity for HABs. This acquisition was funded through the National HAB Observing Network, and it marked a significant step in improving early detection of harmful algal species. The IFCB continuously samples seawater, capturing images of individual particles. These images are then processed through a classifier algorithm that can detect the presence of harmful species and estimate their abundance.
In July 2024, AOOS’s Thomas Farrugia, who coordinates the Alaska Harmful Algal Bloom Network, deployed the newly purchased IFCB aboard the USCGC Healy during a NSF-funded Arctic Observing Network research cruise. The expedition traveled from Dutch Harbor, AK, through the Bering, Chukchi, and Beaufort Seas, reaching Banks Island in the Canadian Arctic before returning to Nome. During this time, the IFCB continuously monitored for HAB species, providing both an early warning system for potential toxins in the food web and a valuable dataset for future research in an under-sampled region.
The need for more advanced monitoring became evident in the Alaska Arctic during the summer of 2022, when a large and unexpected HAB was detected. This event surprised local communities and members of the Alaska Harmful Algal Bloom Network, prompting AOOS to invest in improving detection and monitoring systems. The IFCB’s deployment on the Healy is one of many efforts to enhance Alaska’s HAB monitoring capabilities.
Map of the samples taken by the IFCB while on the USCGC Healy in July 2024. Red boxes highlight Alexandrium cells.
During the cruise, on July 5th, the IFCB detected a bloom of Alexandrium, the organism responsible for producing toxins that cause paralytic shellfish poisoning. This bloom was found in the Bering Sea, halfway between St. George Island and mainland Alaska. In response, a team of researchers and community members quickly drafted and distributed an advisory to nearby communities, warning them of the bloom’s potential impact on subsistence foods and providing information on how to report any related health or wildlife issues. Fortunately, no reports of illness followed this detection.
AOOS plans to deploy more IFCBs on future research cruises and in strategic nearshore locations to monitor throughout the open water season. By collaborating with the Alaska Harmful Algal Bloom Network and local communities, AOOS aims to expand HAB detection efforts across Alaska.
For more information on IFCBs, HAB monitoring, or the Alaska Harmful Algal Bloom Network, contact Thomas Farrugia at farrugia@aoos.org.