Threat to Right Whales Complicates Seaweed Research

 Seagriculture EU 2024
Right Whales

Scientists are concerned endangered right whales will be threatened by rope lines as kelp cultivation increases in the North Atlantic. New techniques are being developed to avoid that outcome.

by Gloria Dickie/Reuters

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 funneled tens of millions of dollars into such research. If proven viable, seaweed offers a more eco-friendly alternative to corn-based 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,” he says.

Fueling up

For the United States, seaweed aquaculture is still a nascent business, but growing fast. U.S. ocean farmers produced 440 metric tons in 2021 — up from 18 metric tons 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 (DARPA-E) 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 $55 million since 2017 on 21 projects exploring whether seaweed production can be scaled to meet some of the U.S. energy demand.

The department says the country has enough coastline with the right conditions to grow at least 500 million metric tons of seaweed per year — which could make up to 2.7 quadrillion BTUs of biofuel, roughly 10% of the 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.

It’s a balancing act

John Lovett, owner and operator of Duxbury Sugar Kelp, has a narrow 4-hectare (10-acre) farm. When he applied for a permit a few years ago, state regulators made him move his proposed location to a more sheltered area of the bay over cetacean concerns. Now he’s testing out whale-friendly kelp gear in collaboration with Woods Hole. An acre of his shallow water plot is dedicated to research.

Whereas traditional kelp lines are often placed just two meters below the surface, “We pin the kelp arrays very close to the ocean floor,” he said. “Whales theoretically can go over top of it.”

He’s also experimenting with stiff fiberglass rods to replace rope, designed to break rather than ensnare a whale bumping against them. Lovett hopes their designs, once proven, could be taken to future offshore sites in deeper waters where whales travel.

“If whale migrations become so unpredictable and regulations tighten up, we may have to go to stiffer structures, which will increase the price and make it more expensive to operate kelp farms,” said Woods Hole researcher Scott Lindell, the recipient of a $4.9 million DOE grant for sugar kelp biofuel research. “It’s a balancing act between ‘How do we produce low-carbon fuels with minimal risk to protected species?’ and ‘How we can produce a low carbon future?’ ”

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Seagriculture USA 2024



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