I completed the quest etc and I'm now just giving him extra ones, he accepted them earlier but now won't take the 30 sitting in my inventory?

Same thing is happening to me. Before he was saying if I got him all the fish in the spring he'd give an extra special prize. Well, I got 10 more slittifish and he's acting like he never made such a promise.

I'm pretty sure you can only turn in 20 fish total.

has said on the bugs forum that if you have gotten both achievements (the one that gives you the pounding heart as well as the one that gives you the octello) then it's as if you gave them twenty, no matter how many you did give, and you don't need to hand in anymore. he's handling the rest as we speak.

Oh okay, thank you for clearing it up!