NCCOS scientists are providing expertise to a novel project that is exploring the effects of glacial melt on harmful algal blooms (HABs) and the overall ecosystem of Alaska’s Glacier Bay, a fjord system that has a wide range of environmental attributes due to the glacial freshwater influx. Glacier Bay is a 3.3 million acre UNESCO World Heritage Site located in the Inside Passage, an economically important coastal route that is visited by 153 cruise ships and over 3 million people each year.
In recent years, staff from Glacier Bay National Park and Preserve (GBNP) have observed abnormal HABs in various areas of the bay with differing salinity and temperature. Although GBNP’s remote, cold-water environment is often perceived as pristine, changes in environmental conditions and shifting nutrient dynamics may favor the growth of HABs, such as those caused by Alexandrium, which produce potent neurotoxins. These toxins can accumulate in shellfish and pose serious health risks to marine wildlife and humans. Monitoring these harmful species helps resource managers anticipate ecological shifts and mitigate risks to subsistence harvests, wildlife health, and the broader food web within GBNP’s unique glacially influenced marine environment.
To better understand this HABs anomaly, staff conducted scientific assessments in collaboration with the NCCOS Phytoplankton Monitoring Network (PMN) team, who specialize in collecting and identifying phytoplankton species. Sampling phytoplankton in GBNP is essential for detecting the presence and monitoring the spread of harmful algal species that can disrupt marine ecosystems. NCCOS scientists from the PMN program joined the team and trained GBNP rangers on various techniques in collecting phytoplankton samples across the diverse geographies of the bay and measuring abundance of the various species capable of producing harmful toxins. Data collected from this effort will contribute to a larger, multifaceted project already underway that is investigating glacial influence on the overall ecosystem of the bay. Thus far, GBNP staff have been collecting oceanographic data—including salinity, nutrients, and water temperature—as well as data from pelagic fish trawls to estimate species richness and biomass. However, staff had not previously been sampling and identifying phytoplankton presence and abundance in the bay. The team will also be measuring algal toxins in filter feeding shellfish at sites along a glacial gradient to assess the distribution and concentrations of toxins in ecologically important intertidal species. With the addition of these skills, GBNP staff will have a more comprehensive understanding of how the range of glacial influence impacts the bay. The team plans to use the information collected to develop a spatially and temporally explicit model predicting HAB dynamics.
This project is a partnership between NCCOS, National Park Service, University of Alaska and the Hoonah Indian Association.
This work is authorized under the Harmful Algal Bloom and Hypoxia Research and Control Act (33 U.S.C. §§ 4001 et seq.).