Seafood was the main course at this week's weekly luncheon meeting of the Hamilton Rotary Club.

And Bermuda Biological Station for Research scientist Dr. Deborah Steinberg on Tuesday wasted little time in tempting Rotarian tastebuds with a slide show of some of the Atlantic Ocean's deepest dwelling, microscopic delicacies.

Armed with a Ph.D. from the University of California, Santa Cruz, Dr.

Steinberg has for the past few years been taking advantage of Bermuda's deep ocean proximity to study what may be the world's largest migration of animal life.

It happens every day when the sun goes down, she told Rotarians. An unseen, unheard stampede of billions of tiny lifeforms labouring up -- under cover of darkness -- from the oceanic abyss to the surface of the water to feed.

Deepsea dwelling zooplankton such as krill, ctenaphore, heteropods, copepods, and sea butterflies, says Dr. Steinberg, embark daily on a vertical migration the equivalent to walking 25 miles each way just for breakfast. Once at the surface of the ocean, they feast on microscopic plants known as phytoplankton.

At first glance this invisible bug-eat-bug world may seem, well, insignificant. But if Dr. Steinberg's research bears out, it may prove the lowly plankton has a much more significant role to play in the great scheme of global warming.

For their daily bread these zooplankton migrators consume vast quantities of phytoplankton which, in their turn, absorb carbon from an atmosphere polluted with man-made carbon-dioxide emissions.

"By eating plant material in the surface waters at night and swimming downward each day, the migrating animals move a tremendous amount of carbon from the surface to the ocean depths,'' she said.

Meanwhile their impact on the global carbon cycle has yet to be quantified, nor is it known how deep in the water column the carbon is actually transported.

Working from a site 70 kilometers southeast of Bermuda, where the ocean drops to nearly 5 kilometers, Dr. Steinberg hopes to determine how the consumption of phytoplankton affects the transfer of carbon dioxide from the atmosphere to the ocean.

If the zooplankton migrators sink fast enough, says Dr. Steinberg, swimming beyond 300 feet before passing the carbon from their system, the carbon will remain in the deep, unmixed water of the ocean and eventually drift down into seafloor sediment.

This would make it necessary for the surface dwelling phytoplankton to absorb more carbon dioxide from the atmosphere, potentially affecting the concentration of carbon dioxide there, she says.