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Studies from the 1980s concluded that aluminum (Al) was not a significant contributor to Atlantic salmon (Salmo salar) toxicity in Nova Scotia, located on Canada's Atlantic coast, because of the presence of dissolved organic matter that rendered ionic Al ([Al.sub.i]) biologically inaccessible. Since this earlier work, new interpretations of [Al.sub.i] effects, as well as improved techniques for its measurement, have been developed. However, no new data interpretation has been done to see if the conclusions reached in earlier work for Atlantic Canada were still valid. We sampled 97 salmon rivers from the provinces of New Brunswick (NB), Nova Scotia (NS), and the island of Newfoundland (NF) to determine total and [Al.sub.i] concentrations to see if results exceeded newer toxicity standards established by the European Inland Fisheries Advisory Commission. We found that southwestern NS, the region with the greatest loss of salmon populations, has seven rivers where autumn [Al.sub.i] values exceed values identified as toxic to aquatic life. A further three rivers exceed guidelines in NF. Our work shows that the sources of toxicity for salmon and other aquatic species in acidified environments are more complex than previously thought. Des etudes realisees dans les annees 1980 concluaient que l'aluminium (Al) ne participe pas de maniere significative a la toxicite pour le saumon atlantique (Salmo salar) en Nouvelle-Ecosse, sur la cote atlantique du Canada, en raison de la presence de matiere organique dissoute rendant l'aluminium ionique ([Al.sub.i]) non bioaccessible. Depuis, de nouvelles interpretations des effets de l'[Al.sub.i] ainsi que des techniques ameliorees pour mesurer ce parametre ont ete etablies. Aucune nouvelle interpretation des donnees n'a toutefois ete realisee dans le but de verifier la validite pour le Canada atlantique des conclusions des travaux anterieurs. Nous avons echantillonne 97 rivieres a saumons dans les provinces du NouveauBrunswick (NB) et de la Nouvelle-Ecosse (NE) et dans l'lle de Terre-Neuve (TE) afin de determiner les concentrations d'Al total et d'[Al.sub.i] pour verifier si les resultats depassaient les seuils de toxicite plus recents etablis par la Commission europeenne consultative pour la peche dans les eaux interieures. Nous avons ainsi decouvert que le sud-ouest de la NE, la region presentant les plus fortes pertes de populations de saumons, compte sept rivieres dans lesquelles les valeurs automnales d'[Al.sub.i] depassent les seuils de toxicite pour la vie aquatique. Trois rivieres a TN depassent egalement ces seuils. Nos travaux demontrent que les sources de toxicite pour le saumon et d' autres especes aquatiques dans les milieux acidifies sont plus complexes que ce que les interpretations anterieures suggeraient. [Traduit par la Redaction], Introduction Atlantic salmon (Salmo salar) populations in Nova Scotia (NS), Canada, have been seriously affected by acid precipitation (Watt 1987; Clair et al. 2004). Over 30 rivers in that province [...]

Abstract: Atlantic Canada receives the lowest acid deposition amounts in eastern North America, but has some of the most acidic surface waters on the continent, due to the low buffering [...]

Abstract: The nominal catch of blue sharks (Prionace glauca) reported for the Canadian Atlantic grossly underestimates the annual catch mortality of about 1000 tonnes (t), making blue sharks the most [...]

The depleted cod fisheries of the Northern Atlantic coast of Canada should have been subjected to controlled and reduced activity rather than temporarily closed. Analysis of four major cod stocks in the area shows that stock declines were caused by the increased fishing mortality and ecosystem factors. Furthermore, there was a dearth of reliable information of stock status. This last failing needs immediate attention as its solution could be the clue towards the restoration of the project.

The resource management disaster that occurred in the fisheries off the coast of Atlantic Canada has been attributed to various causes, among which was the culpability of foreign fishermen whose boats cruised the Northern Atlantic waters to catch fish. The relevance therefore of a rational and effective international policy on fish resources that border or even encroach on international waters is highlighted.

The collapse of the Northwest Atlantic cod and flounder fisheries in Canada has been attributed to a variety of causes. The most often cited cause is overfishing, which per evidence appears to be a valid one. However, other reasons are worth considering including poor fisheries policy decisionmaking, an attitude problem among fishery owners and an uncontrollable environmental disaster. Even the implementation of the system of individual transferable quotas may be pointed out as a possible cause.

The destruction of the important cod fishery industry in the Northern Atlantic coast of Canada has been attributed to many factors, among which was the increase in the predator population. Seals prey on cod and capelin and their unhampered growth in numbers as well as the increased activity in cod fishing brought about by increased demand from Japan sealed the fate of the cod population. Of course, while the main cause may have been ecological, policy-related mistakes and overfishing may also have contributed to the seriousness of the problem.