Even if salmon survive their initial exposure to polluted storm runoff, contaminants may leave them permanently disabled, new research shows.

In a previous study, researchers at Washington State University showed toxic runoff can kill salmon. In the latest study, scientists found runoff can also damage the hair-like sensors salmon depend on to navigate their watery surroundings and hunt for food.

"We're showing that even if the fish are surviving the stormwater exposure, they still might not be able to detect the world around them as well, which can make it harder for them to find food or more likely for them to get eaten," Allison Coffin, an assistant professor of neuroscience at WSU Vancouver, said in a news release.

Scientists began by collecting storm runoff from Washington State Route 520. They found larval zebrafish — an ideal salmon model — developed fewer lateral sensory hairs after being exposed to the runoff.

Sensor hairs operate similarly to the tiny hairs found in mammalian ears. Vibrations trigger the hairs to send electrical signals to the brain, helping the animal sense and interpret sound and motion.

Coho salmon embryos exposed to storm runoff also developed fewer hairs, but were not as impacted by the pollution as zebrafish.

Scientists also tagged sensor hair cells with a fluorescent protein. The cells glowed when activated. Researchers found the sensor hair cells of salmon and zebrafish exposed to stormwater glowed less intensely than control groups.

"These results suggest that developed hair cells survive acute stormwater exposure but that function is compromised," researchers wrote in the study, published this week in the journal Science Advances.

Stormwater often contains metals, suspended particles and a variety of polycyclic aromatic hydrocarbons. Scientists aren't sure why the fishes' sensor hairs aren't functioning properly after exposure, but it's likely a developmental process is being disrupted by exposure to toxins in the water.

A series of genes must be expressed in order for the lateral line of hairs to develop properly.

"What we think is happening is the stormwater is interfering with that genetic process," Coffin said.

Previous research showed stormwater filtering can prevent runoff from proving deadly to the young fish, but the latest study showed filtration methods had little effect on damage to sensory hairs.

Dutch shipper slams 'toxic' court case
Rotterdam, Netherlands (AFP) Feb 14, 2018 –

A Dutch shipping group blamed for dumping vessels with harmful waste on Turkish and Indian beaches accused prosecutors Wednesday of waging a "populist" campaign against them, based on emotive environmental issues.

In a rare case before the Dutch courts, the northern Groningen-based Seatrade group is facing criminal charges for allegedly violating European waste transfer laws.

Prosecutors are demanding fines of 750,000 euros (930,000 dollars) against three central companies that form the Seatrade group.

Three senior managers could face up to six months in jail for their roles in the breaking up of four ships in 2012.

The "Spring" vessels, which sailed from Rotterdam and Hamburg that year before being broken up in India, Turkey and Bangladesh, contained dangerous substances, including bunker oil, lubricants, chlorine and asbestos, prosecutors said.

If these substances were not removed from the four vessels before they were stripped down, then they must be treated as toxic waste, they added.

Breaking up the vessels therefore put recycling workers' health in danger and polluted the environment, the prosecution said.

Defence lawyer Hans de Jong told judges at the Rotterdam District Court the prosecution was pushing an environmental issue about the "beaching of ships", when the actual case was whether or not his clients had broken EU waste legislation.

"Beaching is allowed and it's done across the whole world, yet the prosecution is demanding jail terms," De Jong said.

He accused prosecutors of "using texts bordering on populism" about environmental issues to boost their case, rather than looking at the actual legal issues at hand.

Investigations by port police revealed that the companies planned to have the ships sailing from Rotterdam and Hamburg six years ago to be broken up on foreign beaches.

A vessel named Spring Bear apparently ran aground in 2012 at Alang beach, in India, while Spring Bob finally came ashore in Bangladesh.

Two other vessels, Spring Deli and Spring Panda, were dismantled in Turkey.

Seatrade's lawyers argued Tuesday that the matter "is not as clear-cut" as prosecutors allege.

In a complex legal argument, the defence maintained that the four ships fell outside of EU regulations once they reached their final destinations to be cut up.

"The moment they became waste ships is when they arrive at the place where they are to be recycled," and therefore the four vessels did not fall under European environmental rules, lawyer Thijs Kelder said.

"Thus, there cannot be any prosecution in The Netherlands," he argued.

Under European rules, all transfer of such waste for elimination is banned to countries such as India, Bangladesh and Turkey, prosecutors said.