I have always thought that being a sportsman had something to do with engaging in an activity where fair play was the essence of the activity. There is the goal of triumphing over another (either a person, a beast, or a condition) within some set of constraints. The more difficult you make it for yourself in relation to your quarry, competitor, or the elements, the more sportsmanlike, unless those conditions negatively affect your quarry.

Needless destruction or despoiling of your opponent, or ruining the field for other players, is unsportsmanlike.

So, fishing with an artificial lure might be considered as more sportsmanlike than baitfishing, because it's somewhat more constraining to the fisherman. This is not to say that bait fishing is unsporting, just perhaps less so than using artificials. Before you jump on me for that comparison, I do both, but I won't use bait if I plan to release the fish, and I think the fish have a high likelihood of being injured by the use of bait.

Gillnetting and dynamite are not sporting tactics, because the fish has no chance at all. This provides an interesting comparison for discussion. Gillnetting is perfectly ethical, but is unsporting. One might say the same for lining techniques. Legal, possibly even ethical. However, I won't engage in flossing, because it is not sporting enough for me. Please note the last two wrods before you launch flaming missles.

In hunting, shooting penned animals is not sportsmanlike, stalking with a bow is the height of sportmanship, because it gives the animal the most chance.

If you use tools and techniques that are too light, or too destructive to your quarry, then you're out of bounds. This might include using .22 shorts for deer hunting, or 1 lb leader for catch and release steelhead fishing, because too many animals die incidently when such gear is used. Of course, for some people, they may be able to use such tactics in a fair manner - the sportsman will decide for himself what is right.

That's how I look at the question.