MAUI YOUTH POSTER CONTEST: Maui youths in grades kindergarten to high school can participate in an International Year of the Reef Poster Contest. Artwork must be no larger than 11-by-17 inches, with paint, markers and crayon accepted. Entries should not be matted or laminated and must have student name, phone and teacher name on back of poster.

Winning submissions will be displayed on Maui buses and at Haleakala National Park and the Hawaiian Islands Humpback Whale National Marine Sanctuary. Mail posters by May 30 to: Kuhea Paracuelles, County of Maui, 200 S. High St., Wailuku, HI 96793.

FAMILY HIKE IN MAKIKI: Family teams will explore Makiki Valley, 9:30-11:30 a.m. May 31, searching for evidence of past and present inhabitants through signs like pig tracks, bird feathers and more. Start at the O'ahu Nature Center. For ages 5 years and older; fee $14 for each nonmember parent/child team. For information, contact Pauline Kawamata at 955-0100, ext. 18.

'AINA HAINA BEACH CLEANUP: Beach Environmental Awareness Campaign Hawai'i will hold an invasive algae beach clean-up 7:45-10:15 a.m. June 1 at Kawaiku'i Beach in celebration of World Ocean Day. Bags, gloves and water will be provided. Volunteers can bring a bucket and rake, and are asked to wear a hat, sunscreen and covered shoes. Register by May 30 by calling 393-2168 or 554-2902. Information: www.b-e-a-c-h.org.

CORAL SPAWNING VOLUNTEERS: Volunteers are sought to collect coral egg-sperm bundles from spawning coral (M. capitata) in Kane'ohe Bay starting at 7:30 p.m. June 3, 4 and 5. The work at the Hawai'i Institute of Marine Biology's Coconut Island will assist a University of Hawai'i oceanography graduate student. Volunteers may snorkel or work in inflatable boats, will receive an orientation and can be provided transportation to and from the UH-Manoa campus. Information: Jackie at jacquelinelpg@gmail.com.

WAIMEA VALLEY GREETER: Volunteer greeters are sought to work one day a week for 2 1/2 hours at O'ahu's Waimea Valley. Information: Kelly Perry, 638-7766, ext. 203.

OFFICE HELP FOR PALMYRA: A few hours of office work a week in Honolulu can help The Nature Conservancy's program at Palmyra. Volunteers should be comfortable working with spreadsheets and communicating with the Palmyra field station staff over the phone. Information: palmyra_admin@tnc.org.

Please submit items for this calendar to dleone@honoluluadvertiser.com.