A tangled mass of rope estimated to weigh in excess of 40 tons washed ashore last month at Kamilo Point in Ka‘u, the latest in an uptick of seaborne debris accumulating on Hawaii shores.
The mass, an entangled agglomeration of fishing rope and nets, was swept onto the Kamilo Point rocks in late January. University of Hawaii researcher Sarah-Jeanne Royer said the mass likely weighed more than 40 tons, although some of it might have washed back out to sea since it was first discovered.
The state Department of Land and Natural Resources has supervised the removal of eight similar masses from shores throughout the state within the past month, reported Clifford Inn with the DLNR’s Division of Boating and Ocean Recreation. Inn said so many net masses in such a short time is very unusual, but can be attributed to seasonal current changes.
A vast amount of seaborne debris flows along the North Pacific Gyre, the oceanic current that cycles from Southeast Asia to the West Coast of the United States, Inn said. However, as the seasons change and weather patterns shift, some debris breaks out of the gyre and drifts elsewhere.
Some of the net masses recently reported could be tied to a 2-mile-long garbage patch that was reported flowing through the Kaiwi Channel between Oahu and Molokai earlier this year, according to a DLNR report.
Kamilo Point often is referred to as “Plastic Beach” because of the high volume of seaborne refuse that washes ashore there.
Net masses can pose significant dangers to boaters who encounter them, Inn said.
“A big net mass could stop a boat in its tracks,” he said. “The rope can get caught up in the propeller and do a lot of damage. They’re quite formidable.”
In addition, net masses can trap and strangle large sea life that get caught among the nets, while non-indigenous fauna can arrive in Hawaii after hitching a ride on seaborne debris, Inn said.
Removing the mass will be a struggle. A net mass that washed ashore at Black Point on Oahu took three or four days to remove, Inn said — and that mass weighed “only” 2 tons.
Net masses can only be removed through days of painstaking labor, with workers cutting through individual ropes with knives until sections of the mass can be carried away, either by hand or by vehicle, Inn said.
Despite the difficulty of the work — made more so by the hostile terrain masses often wash upon — debris must be disposed of as quickly as possible before they break down, leaching contaminants or microplastics into the water.
While the DLNR attempts to dispose of large debris before it washes ashore, tracking garbage patches can be nigh impossible, Inn said.
The University of Hawaii’s International Pacific Research Center is conducting a project where researchers attach GPS trackers to garbage patches in order to predict their movements. The project uses only short-lived trackers, although it is in conjunction with a NASA project that will deploy GPS buoys on marine debris for more than a year.
Until then, however, debris has to be reported before it causes damage.
“Fishermen love net masses,” Inn said. “They attract the small fish, which attract the larger fish that eat the small fish, all the way up the food chain. Sometimes, they don’t even report them until they’ve already caught all the big fish, and then it’s nearly past the island and we can’t find it.”
Nevertheless, there is no shortage of ocean garbage to recover. Bill Gilmartin with the Hawaii Wildlife Fund estimated the fund has recovered more than 231 tons of garbage from the ocean in the past 15 years. Eight million tons of plastic are estimated to be dumped in the world’s oceans every year.
“That should be enough for all of us to consider our use of plastics and employ the five R’s,” Gilmartin said. “Refuse, reduce, reuse, repurpose, recycle.”
Anyone who spots large ocean debris and net masses is encouraged to contact the International Pacific Research Center at marinedebris@soest.hawaii.edu.
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.