Springtime in the Jungle -- the Gulf of Alaska

ABOARD THE ALPHA HELIX---Bob Day had a feeling something big was happening beneath the Alpha Helix, a University of Alaska research vessel floating on the Gulf of Alaska. From the ship's windows, he saw a large gathering of seabirds floating on swells 100 miles offshore from Seward.

Day, a marine ecologist with ABR, Inc., had not seen this many northern fulmars gathered here before. He suspected the Alpha Helix had just passed an area where the density of salt water changes abruptly--a front where saltier water meets fresher water, a place where small fish feed on an abundance of tiny creatures, and where seabirds are attracted to small fishes.

As Day pondered the significance of the fulmar gathering, oceanographer Tom Weingartner walked by and offered his observations of the sea water.

"There's good mixing here," Weingartner said.

"That's what the fulmars told me," Day said. "(The birds) are good oceanographers."

The ocean beneath the Alpha Helix is like an unexplored jungle. Scientists are aboard to hack their way through the many layers of the Gulf of Alaska to see what's here.

Weingartner, an oceanographer at UAF's Institute of Marine Science, is sampling the water from the surface to as deep as 300 meters to determine its unique character. Some water is especially salty and dense, which is the signature of deep ocean off the continental shelf, a platform of sea floor that extends for about 100 miles off the coast of Alaska. Some water is less salty; by measuring its oxygen isotope values, Weingartner may be able to track this water to the glacier from which it melted.

Dean Stockwell is a researcher from the University of Texas. Using the same water-gathering device as Weingartner, Stockwell collects samples of phytoplankton and the nutrients that sustain them. Phytoplankton are microscopic plants that convert the sun's energy to body mass, which is consumed by a jungle of creatures collectively known as zooplankton.

Zooplankton are the specialty of Ken Coyle, also a scientist at UAF's Institute of Marine Science. Coyle uses a fish finder and a system of fine nets to capture zooplankton that range in size and shape from jellyfish to pinhead-size fleas to creatures as big as a grain of rice that resemble transparent praying mantises. It's a funky world down there, but a productive one.

An amazing amount of life abounds in the Gulf of Alaska. That jungle of tiny organisms is fed upon by small fish, which are fed upon by salmon and other tasty fish, which have done well in Alaska waters in the past few decades. The scientists here on the ship are trying to find out why.

The irony is that the Gulf of Alaska theoretically should not be hospitable to all these species. The most productive waters of the world are typically those scientists call "upwelling" waters, where surface winds cause currents to bring dense, nutrient-rich waters up to the ocean's surface. With a steady supply of nutrients near the surface, phytoplankton thrive, as do the astounding number of animals that live on them.

The waters of the Gulf are mostly "downwelling," which means surface water near the coast tends to be forced down and replaced with nutrient-poor surface water from farther offshore. Somehow, despite this lack of nutrients near the surface, phytoplankton and larger animals continue to thrive in the Gulf.

The scientists will return several more times this year and for the next two years to catch the Gulf of Alaska during different phases--a phytoplankton explosion in April; zooplanktons' response in May; the return of the salmon in July; the increased ocean mixing and current flow in October; and the shutdown of the system in December's darkness. The researchers' goal is to understand how climate variability affects the Gulf of Alaska's waters and creatures. Because not much is known about the Gulf and its multitude of creatures, a few decades may pass before the researchers find the true character of this watery wilderness.