A good horror story has certain elements, first there is the idea that something really, really bad is going to happen by something really, really scary; what makes a horror story even better is not really knowing when the awful deed is going to take place.
Today, there may be a creepy discomfort of horror meandering through the Shuswap and in particular Gardom Lake near Enderby, as government contractors begin to spread the pesticide Rotenone through the entire lake ecosystem in order to kill just about everything, including their target, the yellow perch, an invasive spiny-ray fish that is over-populating that lake – and others.
The kill is described as a “treatment” for the lake, a word that we tend to use when healing ourselves, but for the eradication industry it’s a word that soft-sells an act of death and destruction subjected on many species, so many in fact, that we really don’t know the exact number. We’re told that the treatment will preserve our idea of what a lake should be, and even what a fishery should be.
Kill a yellow perch – save a salmon; this is a reality that may be surfacing in the southcentral BC Interior and it may be one that is linked to the mystery of disappearing sockeye salmon and a possibility that the event is linked to aquatic invasive species (AIS).
This story begins as a rumour that was cast my way from people living on the upper Shuswap River who were seeing fewer salmon and instead, a different fish, perhaps yellow perch in great numbers. I responded with a fishing pole and a trip to the river to see for myself. I discovered that the large number of fish were squaw fish otherwise known as pike minnows – but no salmon to be seen.
Was there a story that needed to be told?
As it turns out, the rumour itself was enough for me to be able to aggregate some research and past media reports that might suggest that the missing sockeye salmon throughout the province might be found in the bellies of the yellow perch an invasive species that has exploded in population, and possibly under the negligent watch of the Department of Fisheries and Oceans (DFO).
While it’s true that pointing the finger at the DFO is rather easy, after all, this federal department lays claim and authority over most of our large lakes and waterways, but there’s a larger circle of dysfunction that emerges here that includes all of us, and the science by which we cast our assumptions.
In the 1980’s, it was discovered that sport fishermen had been using yellow perch as live bait in a number of small lakes in the BC Interior for over a decade. Of course many of these fish would free themselves or be discarded at the end of the day, or even intentionally planted – over time their numbers would grow causing the Ministry of Environment and the DFO to eventually take notice.
As the invasive perch population grew, many in the sport fishing community liked the fact that the perch was yet another fish available to catch, and like their counterparts in eastern Canada, recognized the species as a sport fish. Government departments including the DFO turned a blind eye; they let the perch be promoted as a fish worth catching and with little or no education as to the dangers of spreading the fish to other lakes and rivers.
To this day, some anglers continue to use the perch as live bait and government departments continue to simply do spot monitoring without really comprehending what has been emerging beneath the surface of this issue and the water; or perhaps they know, but are powerless to solve the problem because it’s too late and too costly?
After thirty years, negligence appears to have become defined in various forms.
While the first layer of negligence is certainly with some sport fishermen, the second layer surfaced with the government experts who suggested that there was really no risk, since the lakes were “pot lakes” with no water channels that could feed larger bodies of water – they were content with the fish being landlocked. The third layer of negligence can be found with the bureaucracies that pondered the situation at a much slower rate than the quickly expanding perch population. The fourth layer of negligence might be found within political backrooms where handlers believed that if we, the public, knew the whole story that we might become severely disturbed about the course of events thus far.
Yellow perch and other spiny-ray fish are much higher evolved than trout and are more adaptive to diverse conditions. They broadcast their eggs across the bottom of a lake or slow moving river; they don’t need streams to spawn in. An average a 10-inch perch might have 15,000 eggs while 10-inch trout might have 110 eggs and a spawning sockeye salmon 2500-4000 eggs.
A mature perch will spawn three times during the course of a summer and given warm enough water temperatures will bring off about 30,000 progeny in that period of time. It has been discovered that virtually nothing else eats them but they eat everything else, including salmon, trout and even each other.
Needless to say for over twenty years the perch population has been exploding, while other fish populations have been declining – and as we are replanting trout, kokanee and salmon we may simply be providing more feed for the perch.
The Alarm Sounds
It wasn’t until 2006 that the first “public” reports in the media surfaced which suggested that perch may put salmon stocks at risk. In July of that year Scott Simpson of the Vancouver Sun reported that fisheries biologists in Kamloops were scrambling to deal with the “voracious alien fish species threatening to wreak ecological disaster upon some of British Columbia's most important salmon runs”.
The report said the yellow perch, “breed like rabbits and eat like locusts”, The news story was based on a DFO study that had yellow perch in two lakes that drain into the Adams-Shuswap system, which supports the world famous Adams River sockeye run.
Trying to “fix” nature
The public reports made in 2006 served as a warning, however in the following months it became clear that there was no real plan to combat the perch problem, and that the fish would grow an invasive assault on salmon habitat sooner than later.
Upon closer examination of the culture of fish management, suggests that we eagerly mess with nature at all levels. For decades fish managers supported introductions of exotic species to B.C.’s lakes and streams. Brook trout native to eastern Canada are now found in many BC lakes, with sterile brook trout still being released today. At one time brown trout were introduced and are still found in some watersheds. And probably the most common of the officially introduced species is the Rainbow trout which were planted in many landlocked lakes in the Interior which never had trout in them before.
Questions emerge about the “research”
At the core of the problem may be lack of research support. Scott Hinch, a salmon ecologist at the University of British Columbia, says successive federal governments have cut back on research and now, too little is known about what happens to the fish after they spawn and before they return.
Hinch told Canadian Press last December that it's not clear how changing water temperatures are affecting the salmon's food supply in the ocean, or what new predators could be targeting salmon or competing for food.
According to the Johnson 2009 assessment:
In the absence of natural predators yellow perch have been known to out-breed and out-compete native fish species, including salmonids, and can dominate smaller lake systems in just a few years (Scott and Crossman 1973; Clady 1978; Fraser 1978; Shrader 2000; Bonar et al. 2005). The concern in B.C. is with potential impacts on Pacific salmon, particularly sockeye salmon, if yellow perch are introduced into nursery lakes, such as Shuswap Lake. Shuswap Lake is a large (surface area 310 km2) relatively shallow (mean depth 61.5 m) multi-basin lake located in the southern interior of B.C.
Shuswap Lake is a very valuable salmon-producing lake and there could be serious ecological, economic, and social consequences if yellow perch invade this lake. In particular, Shuswap Lake is the nursery lake for juveniles of the most abundant sockeye salmon population in B.C., Adams River, which has in the past supported large commercial fisheries often worth hundreds of millions of dollars. Yellow perch could compete with and also prey upon salmon juveniles and fry, particularly if there is significant habitat overlap between yellow perch and salmon. Juvenile sockeye salmon generally utilize the pelagic zone of Shuswap Lake and impacts of a yellow perch invasion would likely be greater if yellow perch also inhabit pelagic regions of the lake. Shuswap Lake is also an important source of chinook (Oncorhynchus tschawytscha) and coho (Oncorhynchus kisutch) salmon, which could also be at risk if yellow perch are introduced into the lake.
It’s becoming abundantly clear that both researchers and DFO officials have known for some time that perch destroying the sockeye represents a time bomb, and in fact that bomb may have been detonated. If research and recommendations were made too late then eradication programs may be 2-3 years too late as well. The high cost of eradication may cause decision makers to be reluctant to take action as they juggle budget constraints.
The Eradication Industry is alive and well in the Shuswap
As the perch populations grow and sockeye numbers diminish. One industry takes a downturn, but another one is set to grow.
To date yellow perch eradication contracts have numbered in the millions of dollars and once eradication is required for Adams and Shuswap Lakes the price tag may reach into the billions, and all because of a slow moving decision-making process that can’t keep ahead of the prolific breeding of the perch.
According to the Johnson report findings:
In B.C., yellow perch are now present in 78 lakes and rivers, in the Thompson Region, eight water bodies containing yellow perch are connected to downstream salmon populations (Runciman and Leaf 2008). At least four lakes (Forest, Skmana, Gardom, and Adams) that contain yellow perch have downstream outlets that flow into Shuswap Lake, making the natural dispersal of yellow perch into Shuswap Lake a real possibility and may have happened already.
The eradication of the fish involves the extreme act of poisoning the lake with Rotenone which kills all the aquatic lifeforms including amphibians. Other life forms may be placed at risk including songbirds.
The Johnson report outlines the costs associated with such eradications:
The “Rotenone” management action was estimated to cost $380,000 per year over 4 years in order to treat all the lakes in the Thompson region that contain yellow perch and have potential downstream connections to Shuswap Lake. This included Skmana Lake ($200,000), Forest Lake ($250,000), Nellies Lake ($30,000), and Gardom Lake ($550,000), as well as Phillips, Fleming, Skimikin, and Miller Lakes ($500,000).
The cost of the “Rotenone” action included not only the cost of the chemical itself, but also the cost of all the necessary equipment (e.g., boats, trucks, and sprayers), fuel, food, and water for citizens residing on the lake.
Invasive species may also have large economic consequences, not only because of their impacts on industries such as agriculture, aquaculture, and forestry, but also because billions of dollars are spent on efforts to control and eradicate invasive species every year (Pimentel et al. 2000; Colautti et al. 2006a).
It is estimated that the total damage and control costs of invasive species in Canada is between $13.3 and $34.5 billion CDN per year, with damages caused by AIS costing nearly $750 million CDN per year (Colautti et al. 2006a). In the United States, it is estimated that the total damage and control costs of invasive species is $137 billion USD per year (Pimentel et al. 2000).
Worldwide the impact of AIS is estimated to cost more than $314 billion USD per year in damage and control costs (Pimentel et al. 2005). None of these cost estimates include the value of losses in biodiversity or ecosystem services.
Mixed signals as early action again becomes delayed
Lynda Ritchie a DFO biologist has been examining the invasive fish behaviour in the larger lakes like the Adams and the Shswap, and she insists that perch are not yet established in those lakes. A question remains that if six perch were found in Adams Lake does that mean that there could be 600 fish actually in the lake?
Ritchie suggests that might be the case if the perch population was established, but she’s confident that the population is not yet established.
However she does state, “We have no way of determining whether we are targeting an area that perch have for some reason targeted and are congregating around, or if they are spread into other areas of the lake as well”.
New Ruling suggests
misguided direction from the top
A new court ruling this September has shed some light on the corporate culture of the DFO and what has been described as “years of unlawful action by the Government of Canada.”
In the precedent-setting legal victory, the Federal Court admonished the Minister of Fisheries and Oceans (DFO) for failing to identify the habitat of the Nooksack dace, an endangered fish restricted to only four streams in BC’s Lower Mainland. The ruling will ensure greater protection of species-at-risk and their habitats across Canada from the smallest minnow to BC’s massive humpback whales.
In his judgment, Justice Campbell said the lawsuit, was “absolutely necessary.” He described the case as “a story about the creation and application of policy by the Minister in clear contravention of the law, and a reluctance to be held accountable for failure to follow the law.”
Sockeye in the bellies of yellow perch?
At present, the Fraser River sockeye population has severely declined, and the cause of this event has been labeled a mystery which has resulted in the casting of blame that includes commercial and First Nations fishing, sea lice, warming waters, fisheries management and fish farming – all of which is based on one critical assumption – that the 10.5 million sockeye that we believe were hatched in spawning channels, actually made it downstream to the ocean in the first place.
But what if that assumption is wrong?
What if the largest number of those young fish never made it out of inland waterways?
In fact, there might be a different take on what’s destroying the salmon runs in BC, and the best way it can be confirmed or de-bunked is if DFO research findings regarding the current impacts of the yellow perch and other predatory invasive fish species are made public.
The story had warned that the fish had already wiped out populations of prized rainbow trout in several Interior lakes. John Cartwright, a retired fisheries biologist told the Sun that the perch are a "time bomb" that could devastate Thompson River coho salmon, as well as Adams River sockeye. Both those rivers drain into the Fraser River.
In 2006, the perch were present in Skmana Lake and Forest Lake -- and both these lakes support creeks that feed into the Adams-Shuswap system.
"They've got a potential disaster, a time bomb, waiting to go off on the sockeye runs," Cartwright said.
"Their capacity to eat small fish the size of sockeye smolts migrating out of the Adams system is immense - if you get 200 million of these yellow perch in the South Thompson River, its bad news for any salmon, for endangered coho, for sockeye and chinook."
At the time, DFO area director Barry Rosenberger said U.S. research indicates the most devastating impacts are upon coho and chinook because both species remain in their natal rivers for more than a year after birth -- boosting the risk that they will be eaten by the invaders.
Rosenberger had said provincial and federal fisheries biologists have been aware for a decade that perch were present in the region, but typically, they were in "pothole" lakes that were not connected to bigger systems.
"We're trying to talk to community people more, get them understanding what this might mean,"
Rosenberger said at the time. Heavy fines were in place and governments made it clear that it's illegal to use live bait in B.C. freshwater lakes and streams. The provincial and federal governments, along with the B.C. Conservation Foundation, offer rewards of up to $20,000 for the arrest and conviction of anyone caught dumping alien fish species in water systems.
Then there’s the introduction of the mysis shrimp to Okanagan Lake as a source of food for the kokanee. While the effort to support the kokanee had good intentions, fishery managers neglected to realize that the shrimp ate the same zooplankton as the kokanee fingerlings. Forty years later the shrimp is one of the primary threats to kokanee in Okanagan Lake.
The examples of invasive introductions are many and most go unnoticed until there becomes a disastrous series of ecological events which then grabs the attention of the public – disappearing sockeye is one of those events as the Fraser River sockeye run has millions of salmon missing thus far.
According to the Pacific Salmon Commission, the sockeye salmon run size at 1.37 million, is the worst on record and significantly below the last two dismal years. Today, DFO’s Barry Rosenberger says that the migration through Juan de Fuca Strait has virtually dried up to zero.
According to Rosenberger, small numbers of sockeye have continued to come around Vancouver Island through Johnstone Strait but that low water flow conditions due to a summer with little rain remains an ongoing challenge for the migrating salmon. Sockeye fishing has been banned for commercial, sport and aboriginal sectors. He stated that there's no estimate of the numbers yet, but hopes are high the pre-season forecast of 17 million pink salmon returning to the Fraser will prove accurate.
Rosenberger made no mention of the perch threat that he had outlined in 2006, instead he says work has already started to get to the bottom of this year's salmon numbers. He says department scientists have access to the information they need, but he says there's a limit to what government can pay for.
However, events unfolding in the BC Interior not only shed some light on what might be impacting salmon runs but suggests that the gloomy outlook presented in 2006 by retired biologist John Cartwright may have indeed come about.
Today, yellow perch and other invasive species have made there way into primary Salmon spawning areas. At present the prolific rate of expansion of the perch continues to move faster than researchers can track numbers and certainly faster than any control action can occur. This past summer, researchers discovered six perch in Adams Lake which means that many more are swimming beneath the surface of one of BC’s most important sockeye spawning areas.
In October of this year poisoning of Gardom Lake near Enderby will occur, this will be the fifth lake in three years that Ministry of Environment biologists hit with Rotenone, an organic poison almost instantly lethal to fish. Gardom Lake has been overrun in recent years by the yellow perch and smallmouth bass. The lake represents yet another access point perch have into the Shuswap Lake and river system which represents spawning and nursery areas for salmon fry.
What we know is that perch can over-run a small lake in a very short period of time – what we don’t know is what an expanding perch population might do in large lakes like Adams, Shuswap and Mabel. We know even less about how we might be able to control such an event and at what cost.
In an SFU thesis prepared by Erica Johnson this past summer titled, A Quantitative Risk Assessment Model for the Management of Invasive Yellow Perch in Shuswap Lake, British Columbia, she recommends that sampling efforts continue in Adams and Shuswap Lakes to monitor whether yellow perch spread and then quantify how they interact with sockeye salmon. The thesis builds on research that dates back to the 1970’s and clearly indicates that perch would eventually pose a major problem for salmon populations.
She adds that, “It is comforting to know that extensive sampling both above and below the site where we have captured six perch, have been free of all AIS species. Perch tend to school and if there were larger numbers we would see that in our catches, but so far we have never had more than one perch in our net over a sampling period”.
Ritchie says all the perch in the larger lake system have been young males.
“This is not to say that there are no female perch in the lake but we believe there are no mature females and therefore no spawning activity. Perch spawning results in highly visible egg skeins which have not been noted in Adams Lake”.
Ritchie also suggests that perch are not known for their aptitude for dispersal. Only the youngest stages tend to move long distances when caught up in current. This would likely make dispersal a downstream activity and if perch were to establish in the Shuswap system from the Adams Lake source it would likely take many more years for Seymour, Anstey and Salmon Arm as well as Mara Lake to succumb to a perch invasion before the main arm and Little Shuswap Lake.
Ritchie admits though that there are many unknowns at the moment including how great the threat is from perch in larger lakes.
“The threat of bass is unknown as well, and where perch, may in the end become just part of the fauna of the lake and find a relatively unharmful niche, bass may prove to be an aggressive addition. Just because perch are in the system in very small numbers does not mean we should underestimate the threat that bass may pose”.
Regardless of the threats in play, Ritchie and the DFO insist that combating the invasive fish problem may still rest with the belief that this is an early and single invasion that can be combated.
“A single invasion may be dealt with through predation, control activities, inability to find other individuals for spawning, etc.” But then she added, “Continued pulses of invasion would greatly increase the likelihood of establishment”.
For provincial biologist Andrew Klassen, the fight against the perch is underway, but he agrees that the solution to the introduction of spiny-ray fish species is larger than the rehabilitation of Gardom Lake.
“We are working with all various government departments, communities and First Nations to come up with solutions including education and awareness campaigns. We have already successfully treated four small lakes within the Thompson drainage, three of them being directly connected with the Shuswap drainage. Gardom is the last directly connected system and is a priority to rehabilitate. Next year we are scheduled to treat the remaining four small lakes which are located in the Turtle Valley. We will be continuing to monitor for new introductions and work with DFO to find a solution for the Adams Lake perch issue,” he said.
The ministry and the DFO response are not comforting according to Huguette Allen a resident of the upper Shuswap near Shuswap Falls, the location of a salmon hatchery. Allen is also a Green Party candidate and passionate about the need to rehabilitate salmon populations.
“I’m shocked that we have already been poisoning entire water systems here, and I think this is indicative of the level of desperation the Ministry of Environment and DFO are at, in trying to combat this problem,” says Allen.
She said that from her vantage point there certainly appears to be a possibility that the perch have already been impacting salmon populations, and she suggests its going to get worse before it gets better.
“I’m not an expert but it appears to me that government has been far to slow with addressing this problem. I really believe that the researchers and biologists working for the ministry and the DFO are dedicated and really care about this situation, but there may now be other interests at play that prevent the right things from being done”.
Allen points out that what’s happening is that an industry is being built around poisoning lakes and suggests that there is a real danger for conflicts of interests to occur.
“When someone is profiting from a lake poisoning contract, then we are at risk of creating an incentive to poison more lakes for greater profits”.
For Allen that’s a dangerous incentive and one that works against nature and not with it.
“We should have embarked on a massive educational campaign ten years ago when the threats first surfaced, government needs to engage local people and the sports fishery, invite solutions and introduce safe technology, before the problem costs us billions of dollars and we lose more of our eco-systems”.
That law, the Species at Risk Act, requires the federal government to identify the critical habitat of endangered and threatened species. The lawsuit was filed in 2007 after the DFO unlawfully deleted habitat maps from the Nooksack dace recovery strategy.
These discoveries linked to DFO’s negligence appears to place into question the integrity of fisheries management and the possibility that sockeye habitat may be at risk along with the aquatic ecosystems being treated with Rotenone.
Justice Campbell ruled that critical habitat for the Nooksack dace was deleted on the basis of an unlawful DFO policy direction. That policy directed that critical habitat information should be removed or suppressed from all recovery strategies for all aquatic species at risk in British Columbia.
The unfolding of this story is made up of many unknowns with potentially dire consequences, and it does have the makings of a horror story, particularly when lakes are being poisoned and the possibility that a river or large lake ends up on an eradication list someday.
But for now, the court ruling may be good news for the sockeye in the BC Interior, particularly if the DFO comes clean on what they do know – or what they don’t know – about the sockeye food chain or better yet the yellow perch food chain.
One thing is for sure, all parties need to move quickly, while you were reading this article, a million more yellow perch may have hatched.
They’re probably hungry already.
Beautiful - Yet the Beast?
Are yellow perch bringing out the worst in us?
According to Andrew Klassen the Small Lakes Biologist for the Ministry of Environment in Kamloops, Gardom Lake has been treated once before, in the 1970’s. The lake was treated to get rid of lake chub, a native species, in an effort to create a better trout fishery. Klassen says that during the 60’s, 70’s, and 80’s it was quite common for the government to treat lakes to remove native “coarse fish”, or non game fish such as suckers, minnows and chub. This was done in an effort to increase production of trout and create stronger trout fisheries.
“This is not something that we would do today, and we have reserved the use of Rotenone to extreme cases where it is our only option to control illegally introduced invasive fish species such as yellow perch and bass”.
Klassen says that the first treatment of Gardom was successful in removing lake chub from the lake, but since that treatment someone has illegally introduced yellow perch and smallmouth bass into the system.
“These species are very good at depressing the entire ecosystem of the lake by directly predating on the native species including fish, insects and amphibians, and also by simply out competing our native species for the same food and habitat - The planning to make this a successful treatment has been going on for over two years. We are confident that any treatment we undertake will be effective at eliminating all of the unwanted invasive fish. We have committed to the public that this will be a onetime treatment and that we do not plan to return in subsequent years”.
Fisheries Biologist Steve Maricle told the Kamloops Daily News that four more lakes in the Turtle Valley near Chase will be on the treatment list next year. All those lakes contain perch, smallmouth and largemouth bass and sunfish. He added that the wiped-out lakes will eventually be restocked with trout. He hopes the word is out about the impact such transplanting can have and it won’t happen again. Kamloops conservation officer Steve Waslick emphasized that a $20,000 reward still remains in effect for information leading to convictions against those responsible.
Despite the reward, authorities have never received a single piece of useful information about those responsible. Waslick said there have been no new reports of perch elsewhere in the area. He hopes that means whoever did the moving in the first place has moved on, but he’s mindful of the fact transplanting perch is not rocket science.
“It’s so easy to do. With a five-gallon pail, you can move perch,” he said. “The fact there has been no new infestations is a good sign.”
Time has proven that Waslick is wrong; there are new infestations as the perch expands its territory all on its own. As well, it’s unknown whether the perch is evolving into faster moving waters as it seeks to feed it’s appetite for salmon fry.
Senior fisheries biologist in Kamloops Brian Chan is all to familiar with the looming crises the perch presents to ecosystems here. In another report by Robert Koopmans found on the Fresh Water Fisheries Society of BC website http://www.gofishbc.com/tips_articles/perch.htm Chan admits that there could be more lakes infested with yellow perch and he refers to infestations in Pinaus, Skmana, Nellies and Skimikin lakes in the Shuswap. Two of the lakes are connected to Shuswap Lake, and he suggests that it’s inevitable the perch will make their way to the bigger lake eventually.
According to Chan, they will likely take up residence in the places favoured by salmon and trout fry and drive the smaller salmonids out.
At Pinaus Lake, fisheries managers are trying to introduce trout that prey on other fish, but it’s not known whether the two species will strike a predator-prey balance. Chan said, the future at Pinaus Lake doesn’t look bright - the perch numbers are expected to increase to a point where trout predation won’t be effective.
“The perch populations will peak and then they will collapse. What you’re going to be left with is a bunch of perch this big,” Chan said holding up his fingers about six centimetres apart.
“You may have 10 or 12-inch perch right now, but that won’t last.”
How long it will take for the crash isn’t known. Pinaus Lake is big and cold and deep and that may slow the perch’s advance. A small, warm, shallow lake like Six Mile Lake outside Kamloops, would be overrun within five years, Chan said.
“It’s getting too close to home with these perch,” he said. “It’s not good news. They are not native here — perch are no where near natural to British Columbia. They are extremely competitive.”
Chan concedes fisheries managers have a “salmonid mentality” in B.C., primarily concerned with maintaining trout and salmon populations, stating that those species are the most prevalent native fish and a sport fishery with a worldwide reputation has been built around them.
“We don’t want to lose that” Chan said.
Maricle said arrangements are being made to provide alternative water supplies. Most residents will have their water trucked in, but it’s possible the farm will be supplied from a well the ministry will drill specifically for the dairy farms use.
The cost of supplying the water to the residents will top $200,000. All together, the Gardom Lake project will cost about $500,000, he said. All the money will come from the Habitat Conservation Trust Fund, a fund supplied by surcharges collected from hunting and fishing licenses.
The ministry has had four public meetings with Gardom Lake residents this past year. While some people were initially opposed, they have realized the impact perch and bass have had and are now on side.
Sporting groups in the area are also on board, he said. The lake was closed to sport fishing this season to keep it from becoming a source of fish for more illegal introductions.
In a report from the Kamloops Daily News written by Robert Koopmans, Kamloops fisheries biologist Steve Maricle said the proposed kill-off of Gardom Lake near Enderby in early October will be his department’s most ambitious lake “treatment” project yet.
Maricle said this project is complicated by the fact there are year-round residents on the lake who depend on it for their water, including an active dairy farm that draws nearly 50,000 litres a day. All residents will be unable to use lake water for at least four weeks.
What if the largest number of those young fish never made it out of inland waterways?
Spawning sockeye salmon
Harvesting salmon roe in order to restore populations at risk
Dead chub line the shore of this lake in Utah after a Rotenone treatment
...since 2006, it became clear that there was no real plan to combat the perch problem...
Gardom Lake near Enderby
"...yellow perch have been known to out-breed and out-compete native fish species, including salmonids..."
"...eradication of the fish involves the extreme act of poisoning the lake with Rotenone which kills all the aquatic lifeforms including amphibians. Other life forms may be placed at risk including songbirds."
"...they (yellow perch) will likely take up residence in the places favoured by salmon and trout fry and drive the smaller salmonids out."
- Brian Chan
(Above) Rotenone treatment in New York and (below) in Oregon.
Ariel spraying of Rotenone over a lake in Arkansas.
Rotenone fish kill in a lake in Minnasota
DFO policy directed that critical habitat information should be removed or suppressed from all recovery strategies for all aquatic species at risk in British Columbia.