The Steinhart Aquarium welcomed visitors last weekend to enjoy a range of interactive presentations in advance celebration of this year’s Earth Day.

Although it was raining downtown on Saturday, families that braved the wet weather filled the California Academy of Science's temporary Howard St. aquarium to about half-capacity while freely exploring the usual exhibits and special Earth Day booths at their own pace.

Volunteers for the Farallones marine sanctuary were running a Jeopardy-like game for children, and celebrating the Fish and Game Commission’s unanimous vote on Friday to expand California’s fishing-restricted marine reserves by over 200 square miles.

“It’s huge,” said volunteer Brendan Laing, 16. “These areas have been badly over-fished, and a lot of the species at risk reproduce slowly. They’ll have a chance, now.”

Steinhart biologist David Chan, presiding over the public feeding of a 240-pound giant sea bass named Bocalo, said that while the move would be of great help to endangered marine life in general, it wouldn’t do much for the huge fish he was presenting.

“Not anymore, anyway,” he said. “Giant sea bass haven’t been found in this part of California in 50 years.”

When a patron asked why Bocalo’s tank only housed the one bass, a small shark and a few moray eels, Chan explained Bocalo set his own agenda for the tank.

“We tried to make it a little more colorful in there, but he even ate the sea anemones,” Chain said.

Also among the presenters was James Callahan, an editor for ClimateChangeEducation.org, who set up a booth with several hands-on tools to educate children and their families about Earth's global warming through role playing space travel.

One family started by estimating the night and daytime temperatures on Mercury’s, Venus’ and Earth's moon so that pretend space ships would be built to withstand the appropriate extremes of heat. Then Callahan asked which planet everyone would like to 'visit' first.

"Mercury!" shouted 10-year-old Bobby Laudisi, pointing to the small, sun-adjacent planet on a small three-dimensional model. The boy and his family had guessed the planet's hottest temperatures with accuracy, and they laughed and high-fived when Callahan saluted them for it.

But they were much farther off in guessing Mercury's nighttime temperature. Despite its small size and close proximity to the sun, the fastest-orbiting planet is incredibly cold during its 700-hour nights. Callahan explained this is because Mercury has no atmosphere –– a man can stand on its surface and his nose will be in outer space, he said.

But Venus, which is farther from the sun than Mercury and has a large atmosphere, has a mean temperature higher than Mercury's hottest day. The reason, Callahan explained, is in the dominant levels of carbon dioxide in Venus' atmosphere. Using tennis balls attached to each other as models for the atomic makeup of gases, he displayed the rigid, tight structure of oxygen atoms and the loose, "jiggling" structure of carbon dioxide, which captures escaping heat rays.

Finishing the demonstration, Callahan handed them all "badges of honor" –– stickers with a photo of Earth printed on them –– for figuring out how the example of Venus could impact our own planet's temperatures, with carbon dioxide well on the rise in recent years.

"I had no idea that's how it worked," said Laudisi's mother, Dorraine. "But it makes plenty of sense now."

In an upstairs classroom was "The Secret Life of Your Dinner," a presentation exploring unusual details of marine life usually associated with seafood: lobsters, crabs, scallops and various fish.

"The rainbow trout is the Superman of fish," said Pam Swan, a local teacher and musician who sometimes works as an independent contractor for the California Academy of Science. She explained as a series of families walked through the exhibit.

"It can go from standing still –– well, not standing, but floating still –– to swimming at 23 miles per hour in one second. That's twice as fast as a cheetah accelerates!" she said.

The fish has a better sense of smell than a bloodhound, and can break a fishing line tested for twice its body weight, even with a hook in its mouth, Swan said. She produced a sample line tested at 40 pounds.

"Do you think you can break this line," she asked, "which isn't even tested for half your weight?" She handed the line to a series of fathers, mothers and children, and none could break it in two.

Explaining the often unusually bright color of tuna steaks, Swan said the meat will naturally turn brown before going bad. Fearing consumers will dismiss browned tuna as spoiled, many fisheries gas the meat with carbon monoxide for 12 hours, which fixes its bright color, but leaves consumers relying on smell to detect its freshness.

"And it results in a lot more greenhouse gases," said one mother.

"Oh, greenhouse gases," exclaimed her son. "I remember those from downstairs!"