The increasing popularity of sushi around the world has resulted in variations typically found in the Western world, but rarely in Japan (a notable exception to this is the use of salmon, which was introduced by Bjorn Eirik Olsen, a Norwegian businessman tasked with helping the Norwegian salmon industry sell more fish in the early 1980s). Such creations to suit the Western palate were initially fueled by the invention of the California roll (a norimaki with crab (later, imitation crab), cucumber, and avocado). A wide variety of popular rolls (norimaki and uramaki) has evolved since. Norway roll is another variant of uramakizushi filled with tamago (omelette), imitation crab and cucumber, rolled with shiso leaf and nori, topped with slices of Norwegian salmon, garnished with lemon and mayonnaise.