Scientists Call for Stricter Oversight on Asparagopsis

Seagriculture USA 2024

The asparagopsis for the Sea Forest testing is being grown in the cool clear waters of Mercury Passage on the east coast of Tasmania. Photo credit: ABC Landline

Sean Murphy reports for ABC Australia’s Landline that safety concerns have been raised about the native seaweed asparagopsis, which is now being commercialized to help farmers reduce methane emissions in sheep and cattle.

Licenses have been granted to eight companies around the world to develop feed additives based on the discovery by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) that asparagopsis can reduce methane emissions in ruminant livestock by more than 90 per cent.

According to marine ecologist Pia Winberg, the methane-busting chemical compounds in asparagopsis are also highly volatile and toxic. “It can affect the staff members who are handling it. It could even affect the food chain that we’re putting it into,” Dr. Winberg said.

The former academic pioneered Australia’s first commercial seaweed farm at Bomaderry in New South Wales, where she grows a native green species for food, pharmaceuticals, and cosmetics. Dr. Winberg said asparagopsis was safe to handle in small amounts, but it was highly volatile and, in the volumes needed to mitigate methane, could be a safety risk. “It can knock people out in the lab. It’s like chloroform and people don’t use that except under fume hoods,” she said.

The bioactive chemicals in asparagopsis are called bromoforms and they are closely related to chloroform, which was widely used as a general anesthetic in the first half of the 20th century. Its use was discontinued because of its harmful effects on humans. The United States Environmental Protection Agency (US EPA) has warned that bromoforms are a probable human carcinogen.

However, one of the companies licensed to grow asparagopsis said this claim was based on extreme toxicity levels. Chief scientist at Sea Forest in Tasmania, Professor Rocky de Nys, said the US EPA finding came from a study where rats and mice were administered acute doses of the chemical.

Meanwhile, Sea Forest is expanding its operations in Tasmania but already has the capacity to grow enough seaweed to mitigate methane in 2 million head of cattle. The company has invested $58 million in developing systems to grow asparagopsis at sea and on land. It is already supplying some farms with an extract delivered in canola oil that fits easily into existing feed systems in beef feedlots and dairies.

The company has been at the center of eight academic trials looking at food safety and animal welfare. The longest-running trial is at Annandale farm in the Tasmanian midlands, where dairy cows have been fed the supplement since late 2020.

The research is being conducted by the world’s largest dairy manufacturer, Fonterra. Company spokesman Matt Watt said tests on individual cows and their milk as well as herd samples had failed to reveal any adverse impacts or residues.

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Seagriculture USA 2024
Contact Phil Ganz



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