Certainly they are the biggest consumers in Canadian Atlantic waters, relevant to fishing exploitation, at least. I can't speak to the whole ecosystem. If you look at the biomass, they might be there, but if you look at individual fish, you can't say, because they go through larval stages.
With respect to access to markets, seal pelts used to be a lot easier to market than they are now, but I would point out that in the past few years there have been sales of tens of thousands of pelts and meat and oil.
The nature of the decision of the WTO does leave a lot of questions. It leaves a great many questions that require, in the opinion of many, clarification through an appeal. It said that there were in fact unfair trade practices, but they were based on moral arguments. Those are very vague. That's what I think would have to be explored in terms of a question to be considered for appeal to another level. That's not yet a final decision, but it is something that is a significant concern.