Overview:The four remaining anglers gear up for a semi-final of epic proportions, fishing for some of the biggest fish of their lives in British Columbia. Here, the whole ecosystem is driven by migrations of fish, so the anglers go on a journey of their own, fishing for Pacific salmon in the sea near Vancouver Island, fly-fishing for bull trout in the beautiful glacier-fed Upper Pitt River and taking on one of the legendary giants of the Fraser River - the white sturgeon. Matt Hayes will be joined by Yves Bisson, an expert Canadian fishing guide, to judge who goes through to the final.