Actually halibut do migrate along the west coast, and a number of IPHC studies have been completed to determine the degree to which over-fishing in Canada for example, might impact the halibut recruitment to AK. Thus the focus on ensuring halibut are properly managed in all management areas along the pacific coast. So what AK does to contribute to discard morts does indeed impact Canada, and we should therefore be paying close attention demanding a more responsible approach. Canada's catch monitoring in all fisheries is far superior to the US counterparts in AK.
As Canada moves to electronic catch reporting for recreational (Minister signed off on it), we will ultimately have a far more robust catch reporting data base than other jurisdictions...although, accuracy of this approach is reliant upon fishers accurately recording catch. We still therefore will require fisher-independent catch monitoring such as creel, log books, and over-flight observations...IMO.
Here's a clip from the IPHC site:
"Based on 2,620 tag returns, it was suggested that as much as 2/3 of spawning stock that is resident in Canadian waters during the summer should be expected to move to Alaskan waters during the winter and be vulnerable to out-of-area interception. However, it was cautioned that the results could be subject to spatial biases in tag recovery rate and that the estimates derived from the analyses should not be considered sufficiently precise to estimate the impacts of intercepting seasonally-migratory fish."