Every day, residents of the eastern Olympic Peninsula are gifted with the sight of the sparkling Puget Sound waters.

Sometimes they even glance the fin of a whale or the head of a harbor seal popping up for air.

But below the waters, there is a miniature world that is as vital to the orca whales as it is to us humans.

That is the invisible world of zooplankton.

Julie Keister, Ph.D., an associate professor at the University of Washington School of Oceanography and expert in zooplankton will be guiding Port Townsendites through this magical, unseen world at the Port Townsend Marine Science Center’s next “Future of Oceans” lecture at 3 p.m. on Nov. 10 at The Chapel at Fort Worden State Park.

“Zooplankton are the mostly microscopic animals of the ocean that serve as an important link in marine food webs,” said Keister, who has a Master of Science in marine sciences from the University of Maryland and a Ph.D. in oceanography from Oregon State University. “They are extremely diverse in their size, shape, behaviors, life cycles, and responses to climate change.”

When people think about climate change in the Puget Sound, the health of the salmon and the Southern Resident Orcas comes to mind first. But the health of the many species of plankton that call the Salish Sea their home is just as important.

“In Puget Sound, we are studying them to better understand salmon survival and climate impacts on the marine ecosystem,” Keister said.

Modern plankton studies are becoming much more precise, said Peter Rhines, an oceanographer who helps organize the lecture series each year.

Both phytoplankton and zooplankton are wonderfully complicated mixtures of animal and vegetable, he said.

“Dinoflaggelates are sunshine-energized vegetables that swim and some zooplankton have all the sex and society and swimming properties of animals, but also chloroplasts that harvest sunlight,” he said. “Zooplankton are tiny: mostly millimeters or less in size. This means that they cannot swim the way we and the fish do, moving forward by paddling to throw water backward.”

Keiffer, working with scientists from NOAA and the Suquamish Tribe, is conducting experiments that will test the effects of ocean acidification on zooplankton growth and development. Over the next several years, she will be expanding these experiments to include the interactive effects of temperature and oxygen change, which are also occurring as part of global and local climate change.

Keister will be presenting this research at the lecture, focusing on how climate-driven environmental change interacts with biological processes to control zooplankton biogeography, diversity, community structure and abundance. These interactions ultimately control ecosystems, including fish and other upper trophic level organisms. As a biological oceanographer and zooplankton ecologist, Keister’s projects combine field collections, laboratory experiments, satellite data and collaboration with modelers.

“The Puget Sound is a brilliant jewel unknown to us because we only see the surface of it,” Rhines said.

Each year, Rhines and organizers with the Port Townsend Marine Science Center choose a host of lecturers to give talks about what is happening in our oceans, ranging from oceanography research, study of tides, ocean acidification, to the health of marine mammals, fish and other sea creatures.

This year, lectures include Kiester’s talk on plankton on Nov. 10; a talk on art and science in the marine micro world by retired NOAA scientist Carla Stehr on Dec. 8; a discussion on large whale research by Cascadia Research scientist John Calambokidis on Jan. 12; and a talk on toxic phytoplankton by Jamestown S’Klallam biologist Neil Harrington on Feb. 9.

To learn more, visit ptmsc.org.