He visited dozens of Hindu temples to discuss the area’s fragile ecosystem — how saris could strangle the sea grass, flowers could choke the birds, and fruit could disrupt the food chain. Since Mr. Zuzworsky left the park in 2008, rangers have become even more creative in spreading the word, joining a panel of priests on a local television channel. Ms. Krause discussed litter before more than 1,000 Hindus at an outdoor reading of the Ramayana.

Cremated remains are a particularly touchy subject. The scattering of ashes in water is among Hinduism’s most sacred rituals, necessary for a successful transition to the next life. The practice has drawn concern from park officials; they issue special permits for spreading ashes on a case-by-base basis, but Hindu leaders acknowledge that some bereaved families do not wait for permission.

Image A popular area for rituals is near the North Channel Bridge. Credit... The New York Times

Most Hindus who visit the beach are immigrants from the Caribbean islands and Guyana who have settled in the Richmond Hill area of Queens. They are largely descendants of Indian workers sent to the Caribbean in the 19th century.

Dozens of Hindu temples fill the blocks surrounding Liberty Avenue, the backbone of the city’s Little Guyana, where fragrant roti shops flank colorful sari stores. Some congregations meet in tight basement quarters, and others in extravagantly decorated compounds, but all profess that important rituals must be conducted by the water.

While some go to the Rockaways or Ferry Point Park, the most popular spot is the beach near North Channel Bridge, as it used to be called. “I love the water, I revere the water, it is my mother,” Mr. Narine said, arms thrust toward foggy Jamaica Bay.

The waters there are not nearly as dirty as the Ganges, which is thick with factory runoff, untreated sewage and, of course, religious offerings. But some Hindu leaders have embraced the park rangers’ message that their offerings threaten the bay.