Mariners, pilots or people near the ocean are being asked to be on the lookout for a massive “ghost net” that was spotted two weeks ago off Maui and might remain a threat to humpback whales and other sea life.

The net — an estimated 50 feet long by 70 feet wide by 50 feet deep with a yellow floater bucket — has remained elusive, in part, because rainy, windy and unstable weather has made search conditions difficult.

The net was spotted a mile west of Molokini islet Dec. 29 by Oriana Kalama of Maui’s Ocean Defender, and a handful of nonprofits began planning the net’s recovery.

The Coast Guard, the state Department of Land and Natural Resources and local boating companies have all been alerted.

“We’re looking for it,” said Ed Lyman, large-whale entanglement response coordinator with the Hawaiian Islands Humpback Whale National Marine Sanctuary.

Lyman, who was conducting whale research on the water Tuesday, said he was prepared to place a transmitter tracker on the large net and then let a larger vessel haul it in.

Ocean Voyages Institute, a California-based nonprofit that has retrieved a number of large nets from the Pacific Ocean, arranged for a sailing cargo vessel to be on standby to retrieve the net this weekend or next weekend.

Ocean Voyages Institute in June used the same ship, the Kwai, to remove 42 tons of netting and consumer plastics from the vast Pacific Gyre between North America and Hawaii.

With another ship, the institute teamed up with Hawaii Pacific University in October to clean up six tons of nets from the reef in Kaneohe Bay.

These huge nets of nylon or polypropylene can weigh tons and drift for decades, gathering plastic debris, ensnaring wildlife, destroying reefs and even threatening vessels.

An estimated 600,000 tons of this abandoned gear finds its way into the oceans every year, according to Ocean Voyages Institute, and the United Nations says some 380,000 marine mammals are killed every year by either ingesting or being caught in it.

As for the latest threat, Nikolai Maximenko, an oceanography researcher with the University of Hawaii’s International Pacific Research Center, said ocean currents have been variable in recent weeks due to the unstable weather, and the net could have drifted anywhere from the shores of Oahu to Maui and Hawaii island.

It already could be stuck on the shore or a reef, he said.

“After two weeks it’s difficult to tell where this net is,” Maximenko said. “With the strong tradewinds, choppy seas and rough ocean, it’s next to impossible to see anything.”

Anyone who spots the net is asked to note its location coordinates and size estimate and send any updates to Mary Crowley, executive director of Ocean Voyages Institute, at mary@oceanvoyagesinstitute.org.

Maximenko said there is another big net threatening Hawaii that scientists are keeping an eye on. A tracker was attached to it in August 2018, and it is now estimated to be 600 miles south of Maui.

These nets are likely not alone. The scientist said derelict fishing gear is part of a growing worldwide problem of marine debris.

“The lifespan of these ‘ghost nets’ is not known but as long as they float they continue killing not only fish, but also sea turtles, seabirds and other marine animals,” Maximenko wrote in a recently published paper. “Washed ashore, partly buried in sand or stuck on rocks, nets are difficult to remove. Every year, fishing nets damage large areas of coral reef ecosystems: the Northwestern Hawaiian Islands alone collect on average an estimated 52 tons per year, with 80 tons removed in 2018.”

Maximenko wrote those words in a white paper he co-authored last year with scientists from Hawaii and around the world, proposing a global Integrated Marine Debris Observing System to track ghost nets and other debris.