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[KarateKick]

Is there any way to look up information on which lakes and rivers are clean enough for the fish to be safe to eat?

For example, many people say Deer Lake in Burnaby is too polluted, but I have not heard about contamination there by anything other than waterfowl.  Is the water clean in areas not close to the beach with the ducks and geese?  Is there a government agency that tests different parts of the lake?

[Long_Cast]

I ate rainbow trout caught at Deer Lake, but this was back in the 1990's and the water colour was light green to light brown. Since the lake is stocked with rainbow trout for people to catch, it should definitely be safe to eat. However, I wouldn't eat any other fish caught at Deer Lake such as the largemouth bass, carp, and catfish as they're fish that are known to accumulate large amounts of toxins, especially the large ones.

[Blood_Orange]

Try Googling "Deer Lake water quality report" and you'll find https://www.theswimguide.org/beach/211 . That site focuses only on coliform bacteria (which can be a danger to swimmers) and not other types of contaminants or pollution.

I doubt you'll find a site that gives you a YES/NO answer about whether you should eat fish from a particular lake because it's more of a sliding scale. Do whatever you're comfortable with! I doubt eating one fish from an iffy body of water would have any lasting effects if the fish itself doesn't have parasites but I tend to be quite conservative about where I keep fish. That said, I wouldn't have a problem keeping hatchery rainbows from Deer Lake.

[RalphH]

there's little to worry about at least in our local lakes. If there is an issue it's usually from heavy metals from industry effluent. If that happens it tends to build in organs such as the liver or kidney and less so in flesh. Our local lakes don't get that sort of pollution. Trout etc don't live long enough to accumulate that stuff anyway and in local lakes most of the stocked fish are cropped off within the fishing season. Coliform bacteria poses no hazard as far as fish consumption though people who use the water including fishers should take care.

There are problems with local clams etc and it might be wise to avoid crabs from Vancouver harbour but trout etc I think the fish are safe to eat.

[TimL]

I would worry more about the clams than the crabs. Clams are filter feeders meaning that they suck in water and filter tiny food particles in the water through their gills..so they are more susceptible to contamination by pollutants, which they filter out and store in their tissues. This is reason why the harvesting of bivalves (clams, mussels, scallops, etc..) is forbidden near urban areas such as Metro Vancouver.
Crabs do not filter feed- the muscle tissue (meat) is safe to consume. However their equivalent of the liver (hepatopancreas, source of 'crab butter') may not be safe to eat in contaminated areas (e.g. dioxin). Same goes with bottom fish (flounder/sole, greenling, perch etc..) caught near industrial areas-the meat is safe to eat but not the liver, since the toxins are filtered through there. 

[Knnn]

There are two primary types of contamination; biological, i.e. viruses and other pathogens or chemical, such as metals, dioxins and PCBs etc.

DFO routinely monitors the quality of shellfish, because they are filter feeders and can become readily contaminated with fecal coliform and other pathogens that can be passed onto humans.  This is why many beeches are closed to shellfish harvesting around built up areas where there sewage or animal fecal matter (ducks/geese etc) is more likely to impact surface water quality.   As noted by TimL, crab meat is generally safe to eat from a biological and chemical perspective, but the hepatopancrease may accumulate chemicals that if consumed frequently enough may pose a risk to human health.

I am not aware of any government agency that routinely monitors the quality of fish meat.  The reason for this (I believe) is that water and food ingested by fish goes through their gut where it is digested and is then absorbed through the gut wall, which prevents the fish meat from becoming contaminated with biological agents.  However, there is a potential risk that fish flesh can become contaminated with chemicals, if the habitat they live in is contaminated.  The degree of impact to the flesh will be dependent on the nature of their food source, the degree of contamination in the environment and the age of the fish.  The younger the fish the less contaminants accumulate within the fish. 

I work in the environmental field and apart from some very site specific locations where significant environmental impacts are thought to be present, such as the Trail lead smelter or the recent Mount Polley mine site release, assessment of contamination in fish is not considered to be warranted. Some fish will also accumulate mercury from natural and man made sources.  This can be an issue in some large marine fish such as Tuna, because the mercury levels can accumulate at significant levels.  However, this is not an issue in shorter lived species such as salmon, where any minor risk of additional mercury consumption is far outweighed by the benefit of eating fish.

While shallow and warm urban lakes with a lot of wildlife may be polluted, that pollution is likely only from fecal matter, which is unlikely to adversely impact the fish flesh.  As long as the guts are removed and the fish is rinsed well I doubt there would be any problem eating fish from these lakes.

[Dave]

It's always good when people who have expertise report back; thanks Knnn

[RalphH]

there has in the past, warnings about eating fish from the Thompson River below Kamloops Lake and in the Columbia below Trail. Both were associated with industrial pollution - a Pulp Mill in Kamloops and the Smelter in Trail. Effluent from these operations either no longer exist or have been cleaned up. A similar restriction was once placed on some species in North Howe Sound due to industrial operations in Squamish. Mostly people were advised to restrict their consumption or specific fisheries (ie for ground fish and crabs in Norther Howe Sound) were closed.

If you look at Page 81 of the Provincial Synopsis there is advice on mercury contamination:

Mercury levels in fish are not routinely monitored across B.C. lakes and streams as the risk of mercury contamination is generally low. Mercury can accumulate in the muscle of fish, with large predatory species such as lake trout, bass and walleye tending to accumulate the highest amounts. Currently, only three areas in B.C. have consumption advisories because of mercury. These advisories are for lake trout and/or bull trout in Jack of Clubs Lake (Region 5) and in Pinchi Lake (Region 7), and Williston Lakes (Region 7). For more information on healthy eating and fish consumption guidelines please visit www.healthlinkbc.ca

Any other health advisories would be made available at the link supplied. I'd also note that trout are neither long lived nor are they apex predators in the eco-niches - trout tend to eat small aquatic life and fish that have short life spans. Overall there are no health concern from occasionally eating trout etc from any water in the Province except as noted

[DanL]

As far as industrial contaminants go, presumably mining and pulp/paper operations would be likely suspects for contamination. Any comment on what sort of contaminants agricultural runoff from farming might be putting into backwater sloughs of the Fraser through the valley and whether that might pose a health risk to people consuming coarse fish (carp, catfish, bass, crappie etc) from those waters?

[arimaBOATER]

Quesnel Lake is one of the deepest lakes in the world.
Big lake with resorts at west side but lots of wilderness.
It had a major mining spill in recent yrs ....
Yous would have a better opinion than I would.
Being that it 's such a big lake plus outlet waters would you think the fish are safe to consume ?
Never fished this lake but some of you may have.
Know the topic is LML pollution but in discussion other areas were brought up in comments.

[Hike_and_fish]

Quesnel Lake is one of the deepest lakes in the world.
Big lake with resorts at west side but lots of wilderness.
It had a major mining spill in recent yrs ....
Yous would have a better opinion than I would.
Being that it 's such a big lake plus outlet waters would you think the fish are safe to consume ?
Never fished this lake but some of you may have.
Know the topic is LML pollution but in discussion other areas were brought up in comments.

There was a recent study done on that lake claiming that the toxic railing have settled on the bottom of the lake and if they lay in disturbed, it wont effect much if anything.

[arimaBOATER]

There was a recent study done on that lake claiming that the toxic railing have settled on the bottom of the lake and if they lay in disturbed, it wont effect much if anything.

Like asbestos in house. Ok till ya renovate or disturb house.
I know gov did water tests right after the spill & said all was good.
But really was thinking about the toxic railing long term & how it will affect quality & the fish.
Very big lake so imagine farther away less is on the bottom.
It always had been a goal of mine to boat every area of this lake.
Dream ..may happen or may not.
Some lake as one drives towords Kamloops from Cache Creek on the left side.
Fish in there but word is "do not eat"
But Quesnel Lake what a jewel & this happens.

[Hike_and_fish]

Like asbestos in house. Ok till ya renovate or disturb house.
I know gov did water tests right after the spill & said all was good.
But really was thinking about the toxic railing long term & how it will affect quality & the fish.
Very big lake so imagine farther away less is on the bottom.
It always had been a goal of mine to boat every area of this lake.
Dream ..may happen or may not.
Some lake as one drives towords Kamloops from Cache Creek on the left side.
Fish in there but word is "do not eat"
But Quesnel Lake what a jewel & this happens.

Yep. It is a shame. What's more of a shame is nobody was prosecuted. Canada has a long history of environmental disasters with nobody being held accountable.

[fishdreamer]

Great post Knnn! Refreshing to read factual content .