Scientists, First Nations team up in fresh attempt to revive struggling B.C. herring stocks
© Squamish Streamkeepers Tiny eyes appear in herring larvae which groups in British Columbia are trying to save. The small silvery fish are a crucial part of the Pacific food web, but have declined in numbers.
Vancouver's Coal Harbour hardly looks like a setting for a potential wildlife refuge. Noisy float planes skitter to and from a nearby dock, storm sewers empty into the saltwater, and high rise towers loom over the water.
But marine biologist Doug Swanston thinks the place has huge potential as a home for herring.
Recently, he rolled three big plastic coolers onto the dock before opening them to reveal a three-metre-long piece of fabric mesh covered with tiny white dots.
"This is probably getting close to a million, maybe 1.5 million eggs if you counted them all," he said as he pulled them into the sunlight.
"The goal is to return herring to Coal Harbour. Historically, we had a spawn here in the 1800s, and it was a source of food for First Nations communities."
The eggs had been collected in a nearby area and the hope is that they will seed future runs.
Herring are a vital, but not very well understood part of the Pacific Ocean's complex food web.
This year alone, 16,000 tonnes have been plucked from B.C. waters. That's about 100 million fish — a low year compared to the glory days of the herring fishery's past. But efforts are underway, in the courts and the ocean, to help the herring.
Vancouver's Coal Harbour hardly looks like a setting for a potential wildlife refuge. Noisy float planes skitter to and from a nearby dock, storm sewers empty into the saltwater, and high rise towers loom over the water.
But marine biologist Doug Swanston thinks the place has huge potential as a home for herring.
Recently, he rolled three big plastic coolers onto the dock before opening them to reveal a three-metre-long piece of fabric mesh covered with tiny white dots.
"This is probably getting close to a million, maybe 1.5 million eggs if you counted them all," he said as he pulled them into the sunlight.
"The goal is to return herring to Coal Harbour. Historically, we had a spawn here in the 1800s, and it was a source of food for First Nations communities."
The eggs had been collected in a nearby area and the hope is that they will seed future runs.
Herring are a vital, but not very well understood part of the Pacific Ocean's complex food web.
This year alone, 16,000 tonnes have been plucked from B.C. waters. That's about 100 million fish — a low year compared to the glory days of the herring fishery's past. But efforts are underway, in the courts and the ocean, to help the herring.
© CBC Marine biologist Doug Swanston holds up mesh fabric covered with tiny fertilized herring eggs. He is researching the impact of transplanting the eggs in the urban inlets of Vancouver.
Tough times for Canadian herring
For decades, the fish were viewed as a virtually inexhaustible resource. They were canned, frozen, used as fertilizer, and even rendered into slippery goo to grease logs being skidded out of the forest.
But the once coastal-wide bonanza is fizzling out. This year, most of the waters off B.C. were closed to commercial herring boats, with the only quota being allowed in the Strait of Georgia, along Canada's southwest coast.
The latest government estimates show that the total mass of Pacific herring in the strait fell from 130,000 metric tons in 2016 to around 54,000 metric tons in 2020 — a nearly 60 per cent decrease over four years.
The first collapse of the stocks happened in the 1960s, due to overfishing. They were allowed to recover but have had ups and downs in recent decades.
The herring fishery in Eastern Canada has also been facing tough times.
For example, an assessment last year for the Gulf of St.Lawrence, predicted the spring spawning herring population is on a trajectory toward extinction in 10 years. Voracious predators and a warming ocean are listed as the biggest obstacles to recovery.
DFO takes 'precautionary approach'
On the West Coast, some groups called for a total closure of the herring fishery this year, but the fishing industry and the Department of Fisheries and Oceans (DFO) pushed back.
In a media release, DFO said the quota was set after conducting "rigorous scientific stock assessments," and "the results demonstrate a healthy and stable herring stock in the Strait of Georgia."
It went on to say the department is "applying the precautionary approach to ensure the long term viability of herring for our ocean ecosystems and harvesters alike."
But that doesn't satisfy a number of Indigenous and environmental groups who are arguing, sometimes in court, for a reduced catch.
Indigenous food for generations
On Vancouver's North Shore, the gravel crunches as Chief of the Tsleil-Waututh First Nation Leah George-Wilson walks along the beach.
For thousands of years, she said herring was an important food for the Tsleil-Waututh people. She recalls her grandparents talking about eating wild herring taken from nearby waters. For her generation though, herring is mostly something left in oral history and traditional knowledge since they were largely fished out in nearby waters.
"You only have to look up the West Coast of British Columbia to see where herring still is and to see how Indigenous people harvest there," George-Wilson told CBC News. "We did similar things and it was an important food source."
The Tsleil-Waututh and other Indigenous groups are working to bring back the fish. And they're partnering with scientists to better understand how herring live and spawn.
© CBC Leah George-Wilson, chief of the Tsleil-Waututh Nation, says traditional Indigenous knowledge can be used to help restore herring and other important sources of food.
How to keep herring eggs alive
False Creek is another built-up urban harbour in Vancouver. It's shallow, has constant boat traffic and home to a number of large marinas. But it's a herring success story.
"Herring are the key. They are the bottom of the food chain," said Jonn Matsen on the dock of Fisherman's Wharf, a sprawling complex where hundreds of boats are tied to wooden docks.
He's in charge of herring enhancement for the Squamish Streamkeepers, a volunteer group dedicated to restoring fish habitat, and pioneers in the field of herring aid.
It started years ago when millions of herring eggs were found on creosote pilings used extensively along the coast to support docks.
The toxic wood preservative was deadly for the eggs, which take about three weeks to hatch. Matsen and others were appalled and set out to fix the problem.
They started by wrapping the pilings in a heavy duty fabric, giving the eggs a fighting chance. They've since expanded to using fine mesh fabric nets suspended below the water line, which give even better protection and survival rates.
The program has been successful enough that this year about 10 per cent of the fertilized eggs are being transplanted from False Creek to the new site in Coal Harbour.
© CBC Jonn Matsen heads up the herring enhancement program for the Squamish Streamkeepers, a volunteer group that has pioneered techniques to create spawning sites for herring.
Crucial for salmon, whales
Matsen said herring are a vital part of the food web, especially for endangered salmon.
"The first thing a salmon looks for when it comes out of the river is food and if you have a herring run right in that area it's just perfect."
He said it only makes sense that part of the salmon's decline is tied to having fewer herring in B.C. waters. Whales, seals, birds and many other creatures depend on the fish as well.
"We found you can bring the whole food chain back, if you start with the herring and work your way up," Matsen said. "It can happen."
Swanston, the biologist, said despite its importance to the environment and as a commercial catch, there are still many mysteries around herring.
For instance, it used to be thought that herring didn't return to their natal waters to spawn, but newer evidence suggests they may have a homing instinct similar to salmon, which return to the streams where they first hatched. It would also explain why herring have disappeared from some parts of the B.C. coast.
Do herring have a homing instinct?
But pollution, development, overfishing and a lack of natural spawning habitat are also factors that need further research and remediation, said Swanston.
The riddle about why the herring spawn in some areas but have disappeared in others is one reason Swanston is fascinated by the experiment to transplant eggs into Coal Harbour.
But he said it will be at least three years for results, because that's how long it will take the tiny eggs to hatch and grow to maturity out at sea.
The hard pressed herring have a low survival rate. Only one out of 1,000 lives long enough to spawn, but if they're allowed to reproduce in the billions, it will be enough to sustain the shimmering schools of fish.
Matsen said herring are a vital part of the food web, especially for endangered salmon.
"The first thing a salmon looks for when it comes out of the river is food and if you have a herring run right in that area it's just perfect."
He said it only makes sense that part of the salmon's decline is tied to having fewer herring in B.C. waters. Whales, seals, birds and many other creatures depend on the fish as well.
"We found you can bring the whole food chain back, if you start with the herring and work your way up," Matsen said. "It can happen."
Swanston, the biologist, said despite its importance to the environment and as a commercial catch, there are still many mysteries around herring.
For instance, it used to be thought that herring didn't return to their natal waters to spawn, but newer evidence suggests they may have a homing instinct similar to salmon, which return to the streams where they first hatched. It would also explain why herring have disappeared from some parts of the B.C. coast.
Do herring have a homing instinct?
But pollution, development, overfishing and a lack of natural spawning habitat are also factors that need further research and remediation, said Swanston.
The riddle about why the herring spawn in some areas but have disappeared in others is one reason Swanston is fascinated by the experiment to transplant eggs into Coal Harbour.
But he said it will be at least three years for results, because that's how long it will take the tiny eggs to hatch and grow to maturity out at sea.
The hard pressed herring have a low survival rate. Only one out of 1,000 lives long enough to spawn, but if they're allowed to reproduce in the billions, it will be enough to sustain the shimmering schools of fish.
No comments:
Post a Comment