That wouldn't work round here. Although 鲑鱼 (guī yú) is the correct technical name for salmon, most people use 三文鱼 (sān wén yú). Salmon is all imported* and 三文 (sān wén) is the nearest they can get to pronouncing 'salmon'. 鱼 (yú) means 'fish'.
So, you'd have to change your name to 三文 (sān wén) for free sushi.
* It was mostly imported from Norway, but they fell out with Norway about some trivial political disagreement. Now it mostly comes from Scotland.