Thousands of demonstrators, many carrying Hawaiian flags, marched through Waikiki on Sunday in an appeal to government to protect Hawaii’s natural resources for future generations.

“The turnout reflects the frustration in the community,” said activist Walter Ritte of Molokai, who arrived on Oahu with his wife, Loretta, Sunday morning to participate in the march.

An estimated 10,000 people clad in red T-shirts participated in the Aloha Aina Unity March on Kalakaua Avenue, from Saratoga Road to Kapiolani Park. The event, its organizers said, was to show solidarity in the Native Hawaiian community on such issues as sovereignty, the regulation of pesticides on agricultural lands and opposition to the planned Thirty Meter Telescope atop Mauna Kea.

The $1.4 billion telescope project was the catalyst to unify more than 30 organizations that included Hawaiian cultural organizations and environmental groups, Ritte said. Mauna Kea is “the spark, the fire” that has awakened and unified the Hawaiian community, he added.

Though the state recently imposed an emergency rule that prohibits being within a mile of the Mauna Kea access road between 10 p.m. and 4 a.m., opponents continue to defy the rule to prevent construction of the TMT, slated to be one of the world’s largest telescopes.

Sweltering in the heat, many marchers held Hawaiian flags, some upside down as a pro-sovereignty symbol. Other marchers held ti leaves, banners and signs in protest against the telescope project.

Dozens of men wore malo and blew conch shells as marchers made their way down Kalakaua Avenue.

Many participants arrived from the neighbor islands early Sunday to participate in the event.

Big Island resident Lanakila Mangauil, an opponent of the telescope project, said Hawaii’s government needs to look beyond economic gain and put the preservation of resources — an area long neglected — at the forefront.

Visitors watched as marchers chanted “aloha aina” — love of the land. A couple visiting from Canada, who stood in the shade of palm trees on a grassy patch on the sidewalk, said they support the Hawaiian community’s stance to protect the land but didn’t care to be quoted.

As sovereignty is the long-term goal, Ritte said more in the Hawaiian community need to be active participants in voting and politics to ensure protection of Hawaii’s natural resources, which he said are rapidly diminishing.

“We’re losing them much too fast,” he said. ”By the time we get to our long-term goals, we’re not going to have any natural resources to pass to our future generations.”