The new Ontario Guide for Eating Sportfish is out, picked it up in the beer store on the weekend...anyone out there look at his book? Gives all the contamination levels in different species of fish throughout Ontario, plus suggestions on the safe frequency of eating the things. I'm always amazed that some of the most toxic fish are up here in the North, I'm guessing because of mining and dams that raised the mercury levels in the watersheds. Anyone else read this publication?

Rob

I have read that guide Rob. It's been a regular give-away at the beer store for a few years now.

Reading it does nothing to make me feel good about the environment. I mean really, having a guide that covers the safe numbers of fish that one should eat when caught from what ought to be pristine waters does make one wonder?

You're probably right on how the lakes were contaminated in the first place.

Dave

_________________
The Wilderness needs strong voices to protect it. And yours can be one of them.
Visit the Friends of Temagami website to learn more.

This booklet is an example that the government can produce meaningful information if the "user group" cares and has enough clout. I picked up the first one when acid rain appeared in the news - in the 80's - and I occasionally refresh my copy. I've also wondered how far north places can have contaminated fish, even in seemingly pristine areas. Aside from mining and pulp mills, I believe that acid rain has been a factor, by leaching out the metals from the base rocks.

From what i've been able to gather, many fish populations in Ontario also bioaccumulate naturally-occurring toxic compounds through the food chain. This occurs in lakes where the bedrock contains heavy metals such as mercury - plankton and invertebrates are exposed to the low background toxins in the water and sediments, then small fish eat these, and concentration of the toxins occurs up the food chain, until in large fish the level of concentration may finally exceed guidelines.

Human-induced elevations of toxins within lake systems will occur, but in lakes distant from such effects, distinguishing between human-induced toxins and those due to natural background becomes difficult. It's been suggested that, as human lifespan increases due to medical advances, and as exposure time to environmental toxins increases (ie. longer lifespan) - switching to a more vegetarian diet might be appropriate.



It's also worth mentioning that the toxicity tests done on fish tissue usually only includes the cheaper ones, such as mercury and heavy metals, and PCBs... the more expensive tests, such as those for dioxin, are far too pricey to be considered... just so you know, when eating any fish caught in the Great Lakes basin.

Rick

It has been largely thought that mercury in northern lakes is primarily atmospherically deposited. The coal mines in the Dakotas are a major source area in NW Ontario and Minnesota.

There has been some recent work on Isle Royale (Nat'l Park in Lake Superior) which suggests mercury content in lakes can be very high in lakes free from human impact (i.e. sediment cores from some lakes show high mercury levels for the last few thousand years). These findings were unexpected. Some lakes (and soils) with high mercury levels are situated next to other lakes with relatively low mercury levels. I think they're still scatching their heads.

http://minerals.usgs.gov/east/baselines/isrohg1.html


The worst areas I know about are near old gold mines where mercury was used to extract the gold.

Interesting stuff....I had assumed that flooding from dams had released exisitng mercury from the soils into the water system....it's difficult to find many waterways in N. Ontario that have not experienced some form of damming at one time or another.....I noticed something else interesting...when I lived in Fort Hope, a fly in Reserve, the fish in the lake that the reserve was on were listed as being totally clean. Another lake in the same water system, about ten miles away, was shown as having a high level of contamination....this kicked in my latent paranoia, wondering if the lake where the native people derived a major portion of their diet was actually free of toxins, or if it was merely indicated that way to prevent an uproar.......

Frozen Tripper said



This caught my eye, because I am vegetarian.

Although it is true that the majority of food contaminations today, do appear to be showing up in the meats and fish we eat, I think we are kidding ourselves if we think that fruits and vegetables are not also capable of causing us problems at the toxin level. We may not have growth hormones present in the plant based foods yet to the extent we do in the commercial meat industry and we probably haven't seen the equivalent of Mad Cow Disease (Mad Turnip) yet,but I believe it has the potential to happen.

It's funny that in my grandparents day, they were encouraged to eat the
organ meats and wild game was preferable. Now the reverse is true - organs collect highly focussed levels of toxins and carcinogenics and commercially fed domestic farm animals are actually safer to eat than their wild cousins because they are not exposed to a part of the food chain that is affected as directly by environmental polutants.

This isn't a criticism of what Tripper said - I agree with him, but by the same token, I think that "all of the products" in our diet are being affected by the growing methods we use and by the levels of pollution in our environment. Meat and fish just happen to be the MOST affected at the moment .... it seems.

Eat whole foods, buy organic when you can, grow your own if you can ...

Dann

_________________
[url]http://LOAFin-Around.blogspot.ca[/url]

My reaction to giving up barbecue...

I don't disagree Kanoe, that plants take up toxins, whether occurring naturally in the soil, or from pesticides - at the same time, a friend was telling me awhile ago about the 200 or so chemicals that are injected into cattle these days, and that was enough to reconsider barbecues permanently... well, at least till the next party.

The idea behind switching to a vegetarian diet relates to bioaccumulation in animals resulting from eating low levels of toxins in plants, and concentrating them.. All else being equal, it's far better to eat grains, rather than the beef that results from grain-fed cattle, since the accumulated toxins will be far higher in the beef.

It's true, though, there are other complicating influences, not the least of which is pesticide use. So I have an organic garden and try to minimize that... still, that barbecued beef's hard to resist when it's there.


Rick

I've always wondered, is it safer to eat wild fish - following the guide - than store bought fish because there is no guide? Are we contaminating ourselves unknowingly? Some people eat fish every Friday. That could mean 52 fish per year. Are we exceeding our limits? I realise much of the store bought fish comes from the ocean. But some of it is freshwater fish. There are no warnings of how much of it we can consume safely. Besides, what are the levels in ocean caught fish?

There are guidelines available for saltwater species. Avoid the top predators that live many years, like swordfish.

Do you eat that much fish? The people who really suffer are those who fish for daily sustenance - including many aboriginal people living on First Nations, and the poor in our big cities.

When I read the title of this thread "Guide ..." I thought I will learn which fish is tastier then all the fish in a pond. As with everithing else - as long as there is variety in the diet, I thing our body, being most excellently designed machine, will pick up what is good and reject what's not.
JJ[/quote]