A marine ecology researcher told a panel sponsored by the Western Pacific Regional Fisheries Management Council on Wednesday that deep-sea mining will negatively impact fisheries in the Pacific, including near-sea Big Island.
Douglas McCauley, a professor at the University of California, Santa Barbara, said seabed mining claims had been staked by nations and private contractors in the Clarion-Clipperton area.
The CCZ is a geological fracture zone running the length of the continental United States from east to west – the western end of which is south of the island of Hawaii.
“The first of these mining claim areas is about 300 kilometers (south) of the United States border (exclusive economic zone) near the Big Island,” McCauley told the panel. He added that mining could start within two years, although he qualified that such a prediction is complicated.
“They’re prospecting there to see what kind of resources are there,” McCauley said. “…Near Hawaii you have a number of claim areas that come from China, Russia – and then everywhere as you walk further east.”
McCauley, who also operates a website called Deep Sea Mining Watch, said the mining planned for the CCZ is for polymetallic nodules, also known as manganese nodules.
He said the noise from deep-sea mining, as well as the mining itself – which will dislodge previously unexcavated sections of ocean floor – will negatively affect fishing.
“You have some sort of extractor…that grinds the materials at the bottom of the sea, sends them through these risers to the mothership that’s operating on the surface,” McCauley said. “And on…these surface support ships, nothing more than the basic processing of mining the ore – the resource that they want to take back to a shore facility to be refined – and ejecting happens.
“As you can imagine there is a huge amount of sewage and waste sludge which is then ejected. It’s sort of a moving or fluid version of the (waste) you would find in a (land) mining operation. There are two plumes that are created…on the seabed where the mining actually happens…and one plume that forms where the sewage is ejected…in the area where the mining took place.
According to McCauley, the sewage plumes – which he says could contain copper, cadmium, iron, cobalt, chromium, nickel and zinc – “have more implications for fishing”.
He said computer modeling was done by researchers from the University of Hawaii and the Massachusetts Institute of Technology to determine the magnitude of these plumes, their extent and their impact on fisheries.
“We won’t know until mining begins what the true spatial impact of these plumes would be,” he said. “…”US fisheries, for international fisheries that operate on the high seas, are some of the most affected when you break them down by country.”
He said the plumes could overlap between 8% and 16% of US fisheries.
“The CCZ is the area where there is the highest level of capture overlap with these mining plume areas,” he said.
According to McCauley, projections of catch data based on the size of plume overlap in fisheries have been made for skipjack tuna, yellowfin tuna and bigeye tuna.
With a 200 kilometer overlap by the litter plumes, it is predicted that there will be an 11.3% encroachment in the skipjack tuna fishery.
“A number of 11% can be big, it can be small. But if mining were to be proposed in 11% of my own backyard or impact 11% of my home garden, I would be upset,” McCauley said. “That wouldn’t be a small number for me.”
Email John Burnett at [email protected]