Arctic Science Journeys
Radio Script

scientists examine sample
NMFS biologist Dr. Jeff Napp (left) and Dr. Mikhail Flint from Russia's Shirshov Institute examine water collected from the Bering Sea. This sample will be analyzed for the presence of a new, and potentially troublesome, phytoplankton species. Photo by Doug Schneider/Alaska Sea Grant.

Plankton Bloom

INTRO: In 1997, at the height of an El Niño summer, a massive plankton bloom turned the sea off Alaska the color of milk, and killed hundreds of thousands of seabirds. Now, scientists say that bloom may have triggered profound changes in the ocean food web. Doug Schneider has more, in this week's Arctic Science Journeys Radio.

STORY: Looking out from the wheelhouse of the research vessel Alpha Helix, things on Alaska's Bering Sea appear normal. Dall's porpoises dart across the front of the ship, while gray whales breach in the distance. As puffins—their bellies bulging with food—take flight from the ship's path, Dr. Terry Whitledge recalls the conditions that led to the massive plankton bloom seen here three years ago.

WHITLEDGE: "One of the interesting and surprising things that happened in 1997 was the appearance of a large coccolithophorid bloom. If it hadn't discolored the water, we might not have discovered it was here until some time later. It happened during an unusual year. It was very calm and sunny, not many clouds, and the water temperature was higher than normal. So it looks like some of these conditions helped establish this coccolith bloom in the Bering Sea. Once you have a small, unusual organism like that, the next question you need to answer is, well, what is this doing to the rest of the ecosystem?"

Coccolithophors have another, equally difficult to pronounce name—Emiliania huxleyi. Simply put, it's a type of phytoplankton, like algae. For three weeks, Whitledge, a University of Alaska Fairbanks researcher, along with scientists from the University of Washington, the National Marine Fisheries Service, and even Russia's Shirshov Institute, will conduct studies aimed at finding out how E. huxleyi may have changed the Bering Sea. The project is funded by the North Pacific Marine Research Program, established by Congress to pinpoint the causes of Bering Sea changes and species declines.

WHITLEDGE: "The information we're gathering will be assimilated into the rest of our understanding of the Bering Sea. We'll be able to say a lot more about whether these changes are very critical for the future of fishing and populations of animals here."

Dr. Evelyn Lessard is a marine ecologist from the University of Washington. She's interested to know whether this new plankton will disrupt the Bering Sea's vital, yet delicately balanced, plankton food web.

LESSARD: "We are doing a comparative study to hopefully capture an Emiliania huxleyi environment, versus what we consider to be a more normal summertime plankton community in the Bering Sea. By comparing the growth and grazing of the small algae in these two different areas, we should be able to tell if Emiliania huxleyi is a positive, negative or neutral organism in this system."

Scientists also want to know if key phytoplankton consumers, called zooplankton, will eat E. Huxleyi. Whitledge says their tough calcium shells may be hard for zooplankton to digest.

WHITLEDGE: "They have little platelets of calcium carbonate, six of them, on their body. They're a bit like little pieces of armor, and so the organisms that crush these in their feeding appendages may have a more difficult time."

If zooplankton can't eat E. huxleyi, the consequences for the food chain could be severe. Zooplankton densities and diversity could take a tumble. Fish and seabirds that eat zooplankton would also be affected. Dr. Jeffrey Knapp is a fisheries biologist with the National Marine Fisheries Service.

KNAPP: "You've got to eat something, and that's where the food chain starts. That's their grocery store. That's one of the reasons for going out this year—is to look at the impact of the coccolithophor bloom. We want to see if it has inserted another step into the food web. Each time you insert another group of organisms eating, the yield to the fish can be decreased. So adding another step could mean a dramatic decrease in the amounts of food or energy ultimately available."

Collecting the data will mean round-the-clock experiments over hundreds of miles of open ocean. It's a project that's expected to take two years to complete.

OUTRO: This is Arctic Science Journeys Radio, a production of the Alaska Sea Grant Program and the University of Alaska Fairbanks. I'm Doug Schneider.

Audio version and related Web sites
Thanks to the following individuals for help preparing this script:

Dr. Terry Whitledge, Professor
University of Alaska Fairbanks
Institute of Marine Science
Fairbanks, Alaska
Phone: 907-474-7229

Dr. Evelyn Lessard, Associate Professor
Biological Oceanography
374 Marine Sciences Bldg.
University of Washington
Phone: 206-543-8795

Dr. Jeff Napp, Fisheries Biologist
Fisheries Oceanography Coordinated Investigations (FOCI)
NOAA/Alaska Fisheries Science Center
7600 Sand Point Way N.E., Bldg. 4
Seattle, WA 98115-6349
Phone: 206-526-4148

Arctic Science Journeys is a radio service highlighting science, culture, and the environment of the circumpolar north. Produced by the Alaska Sea Grant College Program and the University of Alaska Fairbanks.

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Related Web sites

North Pacific Marine Research Program (NPMR): Plankton study

Fisheries Oceanography Coordinated Investigations (FOCI)

University of Washington School of Oceanography