This late in the season the coloration of both is about the same and when neither is fin clipped the only way I can tell is by the gums. And you have to get up close and personal to get them to open their mouths to look. The fight alone is a killer. Often when you release them there are sea lions and sharks lurking and the blood trail from the hook makes them a pretty easy target. I try not to net when there is a chance I will have to return the fish.