Threat to whales complicates U.S. research into seaweed for biofuel

CAPE COD BAY, Mass. — In Cape Cod Bay, 10-year-old Pilgrim and her calf skim the water’s glassy surface alongside the Shearwater research vessel to feed on tiny crustaceans.

The two are among the last surviving 340 or so North Atlantic right whales left migrating along the U.S. East Coast — down from 480 right whales in 2010.

The biggest threats they face include being struck by passing ships or getting entangled in ropes used for lobster fishing off the U.S. East Coast — scientists have recorded 98 such injuries or deaths of whales since 2017.

Now, the whales face another threat as the U.S. Department of Energy tries to boost clean energy production by ramping up research into seaweed, or kelp, as a potential source of biofuel, scientists say.

The DOE has funnelled tens of millions of dollars into such research. If proven viable, seaweed offers a more ecofriendly alternative to cornbased ethanol, proponents say.

But whale biologists are worried. As with traditional lobster fishing, seaweed farms involve fields of ropes strung up underwater for the kelp to grow on.

While there hasn’t yet been a documented case of a whale getting tangled in seaweed ropes, Woods Hole Oceanographic Institution marine biologist Michael Moore is worried: “Wherever there’s rope in the water column, there is entanglement risk.”

FUELLING UP

For the United States, seaweed aquaculture is still a nascent business, but growing fast. U.S. farmers produced 440 metric tonnes in 2021 — up from 18 metric tonnes in 2017.

Most of what’s been harvested has gone into food, pharmaceuticals or cosmetics. But with research sites along the Eastern Seaboard, U.S. officials hope energy leaders might bring seaweed into their biofuel plans if it can be proven as a cost-effective alternative to corn.

“Renewable liquid fuels are especially attractive, because they allow us to leverage existing liquid fuel infrastructure,” said oceanographer Simon Freeman, who heads the DOE’S Advanced Research Projects Agency-energy program funding seaweed research.

Kelp supporters also note that corn, unlike seaweed, takes up increasingly scarce land and freshwater, while also needing agrochemicals that then pollute waterways.

The DOE has spent more than US$55 million since 2017 on 21 projects exploring whether seaweed production can be scaled to meet some of U.S. energy demand.

The department says the country has enough coastline with the right conditions to grow at least 500 million metric tonnes of seaweed per year — which could make up to 2.7 quadrillion BTUS of biofuel, roughly 10 per cent of U.S. annual energy demand in transportation.

For now, kelp can’t beat corn’s low cost. U.S. seaweed production costs, running at $300 to $1,000 per metric ton, need to drop to around $80 to compete with corn, Freeman said.

Big oil companies including Exxon had for years studied the possibilities of making biofuel from microalgae, a plant-like organism that’s invisible to the naked eye, but eventually backed out over concerns about cost and scalability.

“Algae still has real promise as a renewable source of fuel, but it has not yet reached a level that we believe is necessary to achieve the commercial and global scale needed to economically replace existing energy sources,” Exxon spokesperson Chevalier Gray said.

But while microscopic algae is hard to separate from water, larger algae such as sugar kelp is easier to harvest by hand — growing as long as five metres.

IN THE WATER

Kelp grown around New England is often harvested in spring — around the same time North Atlantic right whales feed in the area, slowly following their cold-water prey up to Canada.

The state of Massachusetts has granted coastal permits to five farms for sugar kelp, a strain of large brown seaweed. But they won’t allow any new kelp sites with fixed ropes in deeper waters known to be important areas for right whales, said Christian Pepitas of the state’s marine fisheries division.

For New England waters more than 5.6 kilometres offshore, the U.S. Army Corps has granted permits for 235 seaweed projects since 2018.

Citing concerns over entanglement, the federal government now regulates rope use in the lobster fishery and has implemented seasonal closures. The waters of Cape Cod Bay, for example, are off limits to lobster fishers until all right whales have left.

For states with a large dependence on the lobster fishery, the seaweed development agenda smacks of hypocrisy.

“Maine would have concerns about large aquaculture project siting, particularly with intensive reliance on ropes to grow kelp, at a time when Maine fishermen are being asked to remove rope from the ocean to protect right whales,” said spokesperson Jeff Nichols of Maine’s marine resources department, which has so far permitted coastal seaweed farms covering nearly 50 hectares.