Oceanborne debris has washed ashore on Hawaii coasts at higher rates than usual this year, and cleanup teams are expecting more of the same through 2025.
The Hawaii Wildlife Fund has removed about 350 tons of marine debris from Big Island shores between 2003 and 2023, the majority of which came in the form of net bundles, masses of tangled rope and nets that can weigh hundreds of pounds.
But since late 2023, teams have encountered net bundles more often, said HWF President Megan Lamson.
“We’re definitely seeing an uptick of things washing up,” Lamson said. “It seems like it’s a factor of where the Great Pacific Garbage Patch is right now … Since (last week), we just got reports of two more bundles on the Big Island.”
Lamson said a June 2024 study found a correlation between the drifting movements of the Garbage Patch and the amounts of debris to wash ashore in Hawaii. Somewhat predictably, she said, the closer the patch is to Hawaii, the more garbage lands on the beach.
“The paper showed that about 80% of the increase in debris can be attributed to the patch’s position,” Lamson said.
Because the paper also indicated that the patch moves in a multi-year cycle, Lamson said HWF is predicting a busy year for its beach cleanup teams. And because about 95% of Hawaii ocean debris by weight ends up on Big Island shores — Ka‘u in particular — Lamson urged residents to report net bundles and other debris and to handle them appropriately.
Resident reports allowed HWF to recover more than 3,000 pounds of net bundles from Big Island and Maui coasts this year through a partnership with the Department of Land and Natural Resources’ Division of Aquatic Resources. A “Rapid Response” hotline allows residents on all islands to report large masses of debris so they can get cleaned up quickly.
“We need to get the bundles before a high tide comes in and they get floated back out to sea,” Lamson said.
Net masses present hazards to wildlife and humans alike, as it can be easy to become tangled up in the heavy web of fibers. Furthermore, if left alone at sea, the materials eventually degrade, breaking down into plastic particles that inevitably get consumed by fish and, eventually, people.
Even if they don’t get washed back to sea, Lamson said sometimes people decide to burn net masses. She said HWF was working on the logistics to remove one multi-ton net mass from Ka‘u when it was set afire.
“And now that melted plastic will be stuck on those rocks forever,” Lamson said, adding that burning hundreds of pounds of plastic is generally not advisable for the sake of environmental health.
At the same time, Lamson said that, because net bundles tend to weigh between 300-600 pounds — or more when soaking wet — removing them requires teams of volunteers who cut them into more manageable pieces to remove them.
Big Island residents can call a marine debris hotline at (808) 769-7629 or a statewide hotline at (833) 4DA-NETS. Residents can volunteer for beach cleanups at wildhawaii.org/get-involved/volunteer.
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.