Hi Susan
Sometimes other textile art designs can be adapted.
http://www.ericas.com/embdesigns/dakota/75576.jpg shows a machine embroidery design. Right click image to copy...or print page and enlarge to suit.
This one is likely copyrighted so you might need to take that into consideration.
A google search for
fish "applique pattern" quilt
will give additional possibilities.
Another source to try is a Google Image search. Just click on the Image tab and search for fish, fly fishing, fisherman, etc.
Ann