Was it justified when Idaho chemical treated the Snake River to combat invasive mussels, given the regretful disappearance of aquatic life?

In a bid to combat the invasive Quagga mussels found in Idaho's Snake River in 2023, state officials took a drastic measure. They flooded the Twin Falls area of the river with over 40,000 pounds of copper-based poison, at a cost of $3 million.

However, a year later, more Quagga mussel larvae were discovered, prompting another round of copper treatments. This raises concerns about the effectiveness of the method and its potential impact on the river's ecosystem.

According to a study from the U.S. Geological Survey, the copper treatments destroyed up to 90% of the invertebrates living in the area. Half of the copper settled into its solid form or was absorbed by living things within the first 15 kilometers downriver of the treatment area. Over 7,000 pounds of copper have settled into the riverbed, potentially remaining toxic.

The copper-based toxin used to control Quagga mussels is distributed by the company Earthtec. The product used is sold under the name Natrix, a treatment registered for invasive mussel control through the Environmental Protection Agency.

The treatments, described as the "fastest and most complex" invasive mussel treatment ever done in North America, were intended to address the issue before the mollusks even had a chance to enter Idaho waters. Inspection stations were set up for this purpose, as stated by Lloyd Knight, the agency's deputy director.

However, David Wong, a Quagga mussel management researcher, criticised Idaho's approach for having lethal effects without eliminating the Quagga. He pointed out that state officials didn't know where the adult mussels producing larvae were, which made their treatment plan unlikely to succeed.

Tewalt, another official, dismissed Wong's concern about missing adult mussels, stating that searching for them doesn't serve a strong purpose. He also mentioned that the copper treatments in 2024 were more robust, aiming to address any shortcomings of the first treatments.

The copper treatments in 2024 went further upriver and checked the copper concentrations to ensure consistency at different depths of the water. In 2024, state officials didn't find any adults before their treatments.

The Quagga mussels found in the Idaho river in 2023 were microscopic. If left unchecked, these mussels can become clogged in hydropower water intake pipes, potentially causing power outages and increased costs, as stated by Idaho Power biologist Michael Stephenson.

Gov. Brad Little characterised the treatments as "absolutely critical" to avoid the consequences of a Quagga infestation. However, the treatments have not been without incident. The copper treatments killed 48 white sturgeon out of a local population of 49.

As the battle against the Quagga mussels continues, state officials and researchers grapple with finding a balance between eradicating the invasive species and minimising harm to the river's ecosystem.