The Mount Desert Oceanarium, which highlights coastal marine life and habitat, is like a combined science class and petting zoo.

Overlooking Thomas Bay, the Oceanarium features a lobster hatchery, where hatched eggs from the female lobsters and raised through various stages before the juveniles are released into the sea. Visitors also learn how lobsters are caught and about other forms of commercial fishing and related conservation practices.

Offered, too, is a guided walk through a salt marsh that is home to a rich variety of marine creatures ranging from an American mink to a belted kingfisher. A discovery pool enables visitors to touch some of the animals.

Southwest Harbor residents David and Audrey Mills founded the Oceanarium in 1972. They initially opened the facility in part of their own home, but eventually moved it to its present scenic, seaside location.

David Mills introduces oceanarium visitors to a lobster.
PHOTO BY ALLEN FENNEWALD

“We teach about the marine life and commercial fishing in Maine. A lot of fishermen have come and love us talking about their work and how well they take care of the lobster resource,” David Mills said. “They are hard-working, and it’s dangerous work, [but] they love doing it, They are awfully friendly, salt-of-the-earth kind of people.”

Visually, the lobster hatchery has a sci-fi quality. Several tall cylindrical incubator tanks whirl with 90,000 larval lobsters in total. The water rotates to keep the babies from attacking one another.

“We just had 16,000 hatch yesterday alone,” hatchery manager Emily DeRome said. “We have two big moms with a lot of eggs.”

When the lobster hatchery was in the Millses’ Southwest Harbor home, the lights went out a couple of nights. During the latter power outage, the couple and their good friends, lobsterman Tucker and Bette Spurling, stayed up late into the night, stirring by hand the water in a dozen tanks to keep the young lobsters from attacking each other.

Tucker was one of the first lobstermen to take David out by boat to release the baby lobsters at sea. Once they reach larval stage four (postlarvae), and dime sized, the lobsters are set free in coastal waters through a 25-foot hose.

Bette, who taught nursing at the time, served as a hatchery tour guide for several years.

“I enjoyed it,” Bette said. “There are some things I learned from David, but I knew a lot from being married to [Tucker] for some 30 years.”

Nell Jarzan, 3, touches a sea urchin.
PHOTO BY ALLEN FENNEWALD

After touring the Oceanarium’s hatchery, visitors get to touch sea cucumbers, sea urchins and sea stars.

“Eww, slimy,” Joseph Jarzen of Indianapolis said as he felt a cuke. The sluglike marine animal moves a foot an hour and defends itself by spitting out regenerative intestines.

Sea urchins are round and spiny. Joseph’s cherubic 3-year-old daughter, Nell, was hesitant to touch the prickly ball but, encouraged by Dad, came away unscathed.

Nell was more interested in the sea stars.

“They feel like sandpaper,” intern Beth Horner said. Beth corrects those who call them starfish. They aren’t fish, but echinoderms like the cucumbers and urchins.

As part of the oceanarium experience, David explains how to lobster fish and invites children to come aboard his own boat, the Audrey M, which is on display. During the presentation, he also shows them a live lobster as well as a rare blue one and lets visitors touch them.

On the quarter-mile marsh walk, guide Amanda Granfield invites people to smell wintergreen and sweet fern or nibble smooth cord grass and glasswort. The latter succulent tastes like salty grapes.

“It’s good. I like that,” 11-year-old Anna Lang, a native of Windsor Locks, Conn., reported, nibbling glasswort near the end of the tour.