Heal the Bay’s Santa Monica Pier Aquarium will host presentations and activities for all ages Saturday and Sunday, April 17th and 18th in celebration of Earth Day.

In addition, the aquarium will offer free admission to anyone who first participates in a beach clean-up.

The marine education center at 1600 Ocean Front Walk, beach level at the Santa Monica Pier, will be open from 11 a.m. to 6 p.m. both days for its Earth Weekend festivities. Beach clean-ups will be ongoing throughout the weekend.

Heal the Bay’s monthly “Nothin’ But Sand” clean-up runs from 10 a.m. to noon north of the pier on April 17th. For the remainder of the weekend, participants should meet in front of the aquarium for the clean-up.

Among the scheduled Earth Day activities at the aquarium are

special exhibits highlighting the environmental problems of marine debris, including the work of artist “Deb Ris,” who uses trash found in the marine environment to educate about ocean pollution, and as her artistic medium.

Visitors can also check out marine life off the west end of the pier at the wildlife observation station using binoculars and field guides, and aquarium naturalists will be available to answer questions.

Admission is free for children under 13 when accompanied by an adult. For all others admission is $2, with a suggested $5 donation. Groups of ten or more are $2 per person. But those who help clean the beach can come in for free to celebrate Earth Weekend.

Information, (310) 393-6149, or www.healthebay.org/smpa/.