As diving resumes at salmon die-off site, doctor wants more action to avoid decompression sickness

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A stop-work order on diving at the cleanup site of the salmon die-off in Fortune Bay has been lifted, but a medical specialist in decompression sickness says the number of recent cases involving diving and aquaculture in Newfoundland and Labrador point to a need for better education and communication.

Service NL gave the go-ahead Wednesday for diving to resume at the Northern Harvest Sea Farms site, after issuing the stop-work order Oct. 5 when a diver was airlifted to St. John’s.

Dive teams had been hired to help clean up possibly millions of pounds of rotting salmon inside open-net pens, with one diver surfacing with symptoms of decompression sickness, also known as the bends.

That marks the third diving incident connected to the province’s aquaculture industry that has been reported to Service NL, with one in March and another in August. Service NL will not comment on any of the incidents as they are all under investigation.

The medical director of the hyperbaric chamber at the Health Sciences Centre in St. John’s would not cite specific numbers of aquaculture divers it has treated due to patient confidentiality, but Dr. Ken LeDez said the department has assisted in some treatments, with divers flown to St. John’s out of Botwood “surprisingly quickly.”

“There have been a number of cases, and that’s why we’re anxious to raise awareness about all of this,” said LeDez.

And as aquaculture continues to expand in the province, LeDez said, more diving incidents are unavoidable, and protocols need to be improved.

“There will continue to be cases of decompression illness, and we want to make sure that we’re prepared to deal with them,” he said.

This white substance has flooded the ocean surface near the Fortune Bay cleaning site. (Garrett Barry/CBC)

The dangers of ‘yo-yo’ diving

Diving in aquaculture is inherently risky, with deep pens and chilly water, and divers often going back and forth from the surface multiple times in what medical specialists call “yo-yo diving.”

“It is quite challenging conditions.” said LeDez.

Those repeated ups and downs expose divers to the possibility of gases accumulating in body tissue, which can lead to decompression sickness.

Every diver that has needed treatment has received it.– Ken LeDez

During a cleanup, such as the one underway in the 72 pens in Fortune Bay where the amount of dead salmon could count in the millions — the company has refused to release numbers — LeDez said divers could be working heavily and therefore breathing heavily, although it is hard to generalize.

“The amount of time underwater, and the gaps between dives, there are many factors that can contribute to the occurrence of decompression sickness,” he said.

Some of the divers at Northern Harvest Sea Farms are wearing hazmat suits to carry out their work, CBC News has learned, because the rotting fish ruins their diving suits.

Early treatment essential

Whatever the cause, LeDez said there are concrete steps that need to be taken to improve aquaculture diver treatment. There needs to be more communication and education ahead of time, he said, between diving and aquaculture companies and their employees, government agencies and his hyperbaric department.

He said the department wants to be able to provide its expertise as soon as a diver emerges from the water showing symptoms.

“We need to be involved at the earliest stages.”

Salmon being raised in open net pens like these on in the Coast of Bays-Fortune Bay area on Newfoundland’s south coast began dying in August because of high water temperatures, says Northern Harvest Sea Farms. (Northern Harvest Sea Farms)

LeDez said divers sometimes go to local health clinics, and those people, as well as other first responders, need to be equipped to deal with decompression sickness, which requires immediate and swift oxygen treatment.

“We’d like to have a role, for instance, in providing education and information on how best to respond to these situations,” he said.

The province also needs to increase its monitoring of aquaculture diving and ensure all rules are being followed, he said.

More aquaculture? Get bigger chambers

While the province’s aquaculture industry has come under renewed scrutiny with the Northern Harvest Sea Farms incident, its continued growth seems assured, with expansion on the horizon like Grieg NL’s plans for a massive $250-million farm in Placentia Bay.

And while LeDez felt his department has “done a marvellous job so far” treating divers, there are medical limitations that will need to be addressed.

The department currently has two small hyperbaric chambers that each hold one person at a time, and can administer treatment for only about four hours. LeDez said complicated cases sometimes require far more time in the chamber, and a larger chamber that could also hold more divers would be better suited to that task.

“Every diver that has needed treatment has received it, but I do think it’s important that we move on and get a new multi-place hyperbaric treatment so that we can provide the best possible treatment for the divers,” he said.

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