Since 2020, the Ocean Molecular Ecology (OME) group has collaborated with Ecosystem and Fisheries Oceanography Coordinated Investigations (EcoFOCI) to maintain a seawater environmental DNA (eDNA) time series in the U.S. Arctic. This fall, Shannon Brown participated in the annual EcoFOCI Fall Mooring cruise, which focuses on deploying and recovering oceanographic moorings and collecting shipboard biophysical samples at and between mooring locations. U.S. Arctic marine ecosystems are rapidly changing in response to climate change with accelerating ocean warming and sea ice loss leading to cascading ecosystem effects. OME leverages eDNA approaches to examine the regional biodiversity of microbes, phytoplankton, zooplankton, fishes, and mammals. By pairing eDNA analyses with physical and chemical measurements, these efforts establish critical baselines that support fisheries management and marine conservation. Additionally, in collaboration with the FWC Center for Red Tide Research, our eDNA samples contribute to studying harmful algal blooms (HABs), which can affect marine life and human industries in the region.
During this cruise, Shannon successfully filtered 110 eDNA samples collected from CTD Niskin bottles. The team also deployed an autonomous eDNA sampler at the M2 mooring site. Designed to collect samples biweekly for a year, this sampler had previously been deployed in the Chukchi Sea, where it successfully gathered 24 samples from September 2023 to July 2024. It was recovered in August by the RV Sikuliaq and immediately shipped from Nome, AK to Dutch Harbor, AK, to meet the Fall Mooring cruise.
Monitoring in the Arctic is challenging given its remoteness and the difficulty of navigating harsh sea ice and ocean conditions, making it impossible to manually sample for half the year. Autonomous eDNA samplers are an innovative solution, enabling year-round biodiversity sampling. Due to a limited number of samples and only a few deployment opportunities, we decided to collect one unit, turn it around in the field, and redeploy it for another year.

Redeploying the autonomous sampler highlighted the logistical complexity of Arctic fieldwork. Alaska, the largest U.S. state, lacks road connections between key locations like Nome and Dutch Harbor, requiring equipment to be transported by plane or boat. With only a week between cruises, the team opted to ship the sampler by air—a process fraught with delays. Unfortunately, after countless hours spent coordinating the unit transfer, the sampler missed the departure of the NOAA Ship Oscar Dyson departure date. Fortunately, Han Weinrich was still on the island and ready to receive the delayed unit. A few days after departing, the NOAA Ship Oscar Dyson returned briefly to Dutch Harbor, and the amazing crew retrieved the sampler with a small boat.
Once aboard, Shannon and the EcoFOCI team worked tirelessly to prepare the sampler for deployment within 48 hours. When a malfunction caused the unit to power down spontaneously, Shannon spent hours disassembling and reassembling components to diagnose the issue. With the help of Oscar Dyson’s Chief Engineer (a true MacGyver), foam ear plugs, and some new springs, a solution was found just three hours before the unit was successfully deployed!
Sadly, the sampler was prematurely recovered by a fishing vessel on November 24, just 11 weeks after redeployment. While it’s unclear if any samples were collected, the incident underscores the unpredictable nature of field research in the Arctic. Despite these challenges, this mission highlights the resilience and ingenuity of the scientific team. The data collected through these efforts will inform the sustainable management of Arctic marine ecosystems and improve our understanding of biodiversity in this rapidly changing region. Thanks to the crew of the NOAA Ship Oscar Dyson and the entire science party for a successful cruise!