Their research contributes to the Distributed Biological Observatory (DBO), which, since 2010, has brought together scientists from the United States, Canada, China, Japan, South Korea, and Russia to monitor and better understand the impacts of climate change on one of the world\u2019s most rapidly warming regions.<\/p>\n\n\n\n
\u201cIt\u2019s important to make the same core measurements over long periods of time to get a sense of how things have changed,\u201d says Frey<\/a>, who has worked with colleagues from the University of Maryland Center for Environmental Science (UMCES) and other institutions. \u201cAnnual monitoring in the Arctic allows us to identify changes in these marine ecosystems rapidly.\u201d Frey\u2019s 2023 study in the journal PLOS ONE<\/a> highlights how these Distributed Biological Observatory sites have shifted in recent decades.<\/p>\n\n\n\n Over 14 years, the Clark-UMCES team has been funded four times with over $11 million in grants from the National Science Foundation\u2019s Office of Polar Programs. In 2025, they received a five-year, $3.5 million grant, of which Frey received $772,000<\/a>.<\/p>\n\n\n\n This summer \u2014 Frey\u2019s 16th<\/sup> trip to the Pacific Arctic since 2006 \u2014 she and her colleagues aim to answer an important question: Are Bering and Chukchi sea ecosystems recovering from major sea-ice losses that occurred from 2017 through 2019?<\/p>\n\n\n\n \u201cWhen you don\u2019t have sea ice, you don\u2019t have sea-ice algae,\u201d she points out. At the bottom of the food chain, changes in microalgae that grow on or inside sea ice can be early indicators of shifting dynamics of marine ecosystems and the Arctic\u2019s food web.<\/p>\n\n\n\n As the ice melts each summer, sea-ice algae sink to the seafloor, becoming food for benthic (seafloor) invertebrates. This food web extends to diving, seafloor-grazing animals like gray whales, who eat crustaceans known as amphipods, and walruses and spectacled eiders (sea ducks), who feast on clams, according to Frey.<\/p>\n\n\n\n \u201cIf you care about gray whales or walruses or eiders, you care about sea-ice algae,\u201d she says. \u201cThe changes in sea ice and sea-ice algae have great implications for their ability to survive.\u201d<\/p>\n\n\n\n Aboard the Canadian Coast Guard Cutter Sir Wilfrid Laurier<\/em> in the Bering and Chukchi seas, Frey, her undergraduate and graduate students, and her UMCES colleagues have visited the same biological \u201chotspots,\u201d every year. They measure seawater temperature, sea-ice conditions, sunlight penetration below the ocean\u2019s surface, phytoplankton productivity, water biogeochemistry, and the benthic ecosystems.<\/p>\n\n\n\n Beyond declining sea-ice algae, the decrease in sea ice has led to increased phytoplankton blooms extending into the fall, according to Frey.<\/p>\n\n\n\n She explored this phenomenon with first author Clare Gaffey, M.A. \u201922, Ph.D. \u201924; Geography<\/a> Professor Lyndon Estes<\/a>; and others in a 2025 article<\/a>, \u201cEnvironmental Factors Associated with Fall Phytoplankton Blooms in the Northern Bering and Chukchi Seas,\u201d published in the Journal of Geophysical Research: Oceans<\/em> (JGR Oceans<\/em>).<\/p>\n\n\n\n \u201cThe open-water ocean season is getting longer, seawater is warming, and it\u2019s taking longer for sea ice to regrow,\u201d says Frey, who has reported such findings as a longtime contributor to NOAA\u2019s annual Arctic Report Card<\/a>.<\/p>\n\n\n\n \u201cEven though it\u2019s the fall, and the sun is so much lower, there\u2019s still enough sunlight that these blooms are occurring that late in the season, she explains. And \u201cif you get timing mismatches in a marine food web, it can wreak havoc along the way.\u201d<\/p>\n\n\n\n As the authors concluded, \u201calthough the implications of this are unclear, the emerging growing season could potentially impact ecosystems by extending the temporal activity of grazers and also alter nutrient distributions.\u201d<\/p>\n\n\n\n As Frey and Gaffey observed the increasing number of open patches of sea water due to melting ice on their Pacific Arctic trip in summer 2022, they wondered what was happening below the ocean\u2019s surface as it became exposed to more sunlight. What would that mean for the formation of new sea ice, the growth of phytoplankton, and even how carbon moves through the ocean, influencing the Earth\u2019s climate?<\/p>\n\n\n\n To answer these questions, Frey obtained an additional NSF RAPID grant, which \u2014 along with Gaffey\u2019s NSF Doctoral Dissertation Improvement Grant \u2014 funded participation in an international research expedition to the Chukchi Sea, Central Arctic Ocean, and extending all the way to the North Pole. Aboard the U.S. Coast Guard Cutter Healy<\/em>, the scientists measured phytoplankton, sunlight, and ocean temperatures to understand how these late-season blooms affect the movement of solar energy through the water column extending vertically below the ocean\u2019s surface.<\/p>\n\n\n\n In May 2026, first and second authors Gaffey and Frey reported their findings with colleagues in a JGR Oceans<\/em> article<\/a>, \u201cFresh Phytoplankton Bloom Growth in the Fall and Its Control on Ocean Heating in the Pacific Arctic Region.\u201d (Gaffey is now a postdoctoral researcher at Oregon State University; her work was recently highlighted<\/a> by the NSF\u2019s Arctic Data Center.)<\/p>\n\n\n\n \u201cAt the end of the day, the story\u2019s still the same: The Arctic is warming faster than any other place on the planet.\u201d<\/p>\u2014 polar scientist karen frey<\/cite><\/blockquote><\/figure>\n\n\n\n Shrinking sea ice allows more light into the ocean through \u201cmelt ponds\u201d exposing sea water, according to Frey. A bird\u2019s-eye view indicates melt ponds appearing as dark spots amid the white ice.<\/p>\n\n\n\n \u201cSea ice has a high albedo \u2014 a high reflectance. Melt ponds and open ocean have very low albedo,\u201d she says. \u201cMelt ponds act like skylights, letting sunlight pour into the ocean below.\u201d<\/p>\n\n\n\n To complicate matters, the authors found, \u201calgae blooms don\u2019t just respond to warming \u2014 they also absorb light and generate heat,\u201d Frey says.<\/p>\n\n\n\n Using light measurements, the team \u201ccalculated how much heating is happening in place,\u201d she says. \u201cWhere heat is generated matters just as much as how much heat there is.\u201d<\/p>\n\n\n\n The blooms absorb light and redistribute heat within the water column, changing where heat is stored.<\/p>\n\n\n\n \u201cIf you have a large algal bloom near the surface, the heat is closer to the surface instead of being distributed vertically throughout the water column, and then there\u2019s a cooling effect further underneath,\u201d Frey say. \u201cThat redistribution of heat has the potential to delay sea ice formation and, in turn, reinforce Arctic warming by extending the open-water season, leading to more sunlight and the greater opportunity to have more algal blooms.\u201d<\/p>\n\n\n\n As she reflects on her years of studying the region, Frey concludes: \u201cWith warming and sea ice decline, we have seen some significant changes in Arctic marine ecosystems. The big question that remains now is how resilient these ecosystems are to climate perturbations.<\/p>\n\n\n\n \u201cAt the end of the day,\u201d she adds, \u201cthe story\u2019s still the same: The Arctic is warming faster than any other place on the planet.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":" Over 14 years, polar scientist Karen Frey and her students have studied the effects of melting sea ice in the Arctic, funded by the NSF\u2019s Office of Polar Programs.<\/p>\n","protected":false},"featured_media":28994,"template":"","meta":{"story_color":"var(--clarku-color-blue)","story_headerImg":28994,"section_label":"","footnotes":"","_links_to":"","_links_to_target":""},"categories":[241],"displayed_author":[242],"featured":[493],"topic":[150,160,165,211,218,187,162,134],"class_list":["post-28992","story","type-story","status-publish","has-post-thumbnail","hentry","category-environment-sustainability","displayed_author-meredith-woodward-king","featured-primary","topic-faculty","topic-faculty-research","topic-geography","topic-geography-faculty","topic-geography-students","topic-graduate-research","topic-research","topic-school-of-climate-environment-and-society"],"yoast_head":"\n![\"Eider](\"https:\/\/www.clarku.edu\/news\/wp-content\/uploads\/sites\/37\/Eider-duck-arctic-1024x683.avif\")
\u2018If you get mismatches in a marine ecosystem, it can wreak havoc along the way\u2019<\/h3>\n\n\n\n
\u2018Algae blooms don\u2019t just respond to warming \u2014 they absorb light and generate heat\u2019<\/h3>\n\n\n\n
![\"Karen](\"https:\/\/www.clarku.edu\/news\/wp-content\/uploads\/sites\/37\/Frey-Gaffey-web-845x1024.avif\")