Resources at Risk

Risk Assessments: Learning from Other Jurisdictions

 

Sweden has a great deal to teach when looking at the effects of bleached kraftmill effluents. One reason may be the high level of investigative effort and the strong multidisciplinary approach, particularly in studies off Norrsundet in the Baltic.

 

Clearly the North American research effort is minuscule in comparison, especially in Alberta and the downstream parts of the Northwest Territories. However, as more North American data are reviewed and produced, similarities to Scandinavian work become apparent.

 

Canadian data from Nipigon Bay, showing a shift from perch to suckers, are reminiscent of the species shifts near the Norrsundet outfall. Other Canadian research has shown that Rocky Mountain whitefish and juvenile chinook salmon were "stressed" downstream from pulp mills, as evidenced by high levels of detoxification enzymes in their liver. This agrees with recent Finnish results. Similarly, a study of locations 2.5 km or less downstream of a mill on the Wapiti River in Alberta showed that fish carrying residues of mill-derived chlorinated organic compounds had reduced levels of liver glycogen and had liver damage, as in Sweden.

 

The conclusion of a recent study done for the pulp and paper industry is instructive:

 

At the present time, some scientists in Sweden, Finland, the United States, and Canada believe that the relationship between chlorinated organic compounds discharged in pulp mill effluents and significant adverse environmental effects has not been conclusively demonstrated. Our review of currently available pub" fished and unpublished literature pertinent to the issue supports this conclusion. However, there is a great deal of uncertainty associated with this position, and we recommend a judicious approach be taken when considering impacts of either bleached or unbleached effluents on aquatic ecosystems.  

There is growing evidence that the existing pulp mills on the Athabasca River system may be exerting a significant influence on the water quality of the region. Alberta Environment found that water quality effects existed over 1100 km downstream of Hinton:

 

On all occasions, no odour was detected in the Athabasca River upstream of Hinton. In the first few kilometres downstream of Hinton, odour was always present and was described by the field crews as "pulp mill-like" (i.e., kraft pulp mill). Odour generally declined progressively downstream of Hinton. The rate of decline varied between surveys, with odour appearing to be the most persistent in Survey 89-3. This may reflect the more complete ice cover that was present during that survey compared to previous surveys, and which would reduce volatilization of odourous compounds. In 1988, odour in river water persisted to the vicinity of Smith. In March 1989, odour persisted to the lower-most reaches of the Athabasca River where field crews rated the odour as "high". Particular care was taken to confirm the 1989 evaluations in view of the degree of persistence downstream. The nature of the odour was clearly "pulp mill-like" down to about Smith in both years.  

The N.W.T. Fisheries at Risk

 Primary production in the Slave and Mackenzie rivers is generally light-limited during the open water season as a result of high suspended sediment concentrations and high turbidity. In lakes, where suspended sediments settle out, primary production may be nutrient-limited. The western basin of Great Slave Lake, for example, is much more turbid and much less nutrient-deficient than the eastern basins because of nutrient and sediment loading by the Slave River.

 

Low values of primary production are typical for waters in the Mackenzie Basin, and phytoplankton primary production strongly influences the fisheries yields of many lakes. The yield of Great Slave Lake, which supports the largest commercial fishery within the Northwest Territories, lies above those which might be expected for a large lake with its phytoplankton production, possibly because its tributary rivers, especially the Slave River, supply organic carbon from terrestrial sources which may be important in food chains. The lower Athabasca River and its tributaries, which cut through extensive deposits of tar sands, is probably a major source of such carbon.

 

Commercial fisheries (i.e., those supplying fish for sale or barter) occur throughout the Mackenzie Basin within the Northwest Territories, but most supply only local demand. The Great Slave Lake commercial fishery is the only one with a large export component. Five species are taken, of which the lake whitefish is most abundant, followed, in order, by lake trout, northern pike, inconnu, and walleye (known locally as pickerel).

 

Fish taken in domestic fisheries are especially important in remote areas where the meats, vegetables, and vitamin supplements used in southern Canada are either prohibitively expensive or unavailable. Burbot liver oil is very high in Vitamin A, 500 units or more per gram, compared with raw carrots at 110 units per gram, and in Vitamin D. This species is fished and eaten primarily during the winter when these two vitamins, especially Vitamin D, might be in otherwise short supply.

 

There are several general characteristics of fish populations within the Mackenzie Basin in the Northwest Territories which are relevant to a discussion of bioaccumulation of organic chlorides originating from pulp mills. First, the fish are typically very long lived. Almost all of the species important in commercial and domestic fisheries live into their teens, some into their 20s and 30s. Thus, there is a very long time span over which bioaccumulation can occur. Second, many of the major populations are highly migratory. While they may spawn or overwinter within the Slave and Mackenzie rivers or in Great Slave Lake, a part of their life history is often spent far from these waters. As a result, organic chlorides may be exported from the basin, not dissolved in water, but in the bodies of fish which are subsequently eaten or die elsewhere.

 

The extreme example would be the arctic and least ciscoes which spawn and rear within the lower Mackenzie and the Mackenzie Delta but which, between spawnings, journey long distances along the Beaufort Sea coast, as far as Prudhoe Bay and the Colville River Delta in Alaska and beyond. As a result, loadings of organic chlorides originating from pulp mills in the Canadian provinces may have international implications.

 

These two anadromous species of ciscoes, together with the anadromous lake and broad whitefishes of the lower Mackenzie River (from the Ramparts at Fort Good Hope downstream to the Mackenzie Delta) together number in the millions. They constitute an enormous, presently under-utilized resource, which must be preserved for the use of future generations.

 

In summary, the persistence and bioaccumulative potential of the organochlorine compounds associated with bleach kraft mill effluent are of significant concern to territorial residents. The bioaccumulation of these compounds is a known threat to ecosystems where effluent has been discharged and thoroughly studied by multidisciplinary teams of scientists. As more data became available for the Peace, Athabasca, and Slave River systems, more evidence will come to light as to the nature of existing levels of contaminants from upstream mills. These data must be obtained, thoroughly reviewed, and assessed well in advance of future approvals.

Editor's note: Excerpted from Annex 2 of the Government of the Northwest Territories' submission to the Alberta-Pacific Environmental Impact Assessment Review Board, Fort Smith, N.W.T., 16 November 1989.

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