happytimes, you should fertilize, yes.
You should get the Pond Boss Bob Lusk's book "
Raising Trophy Bass" if you're after big bass. The reality is most people aren't after "trophy bass" - just a good fishery with nice fish.
Page 42 talks about GShad in detail, including statements like: "In the past 20 years, every legitimate trophy bass lake under our care has had a shad population. Every one. It may sound like a bold statement, but it's true. Show me a lake with respectable numbers of bass larger than 10 pounds, and I will show you a lake with a diverse forage base, most often with threadfin and/or gizzard shad complementing the usual cast of characters--minnows, frogs, crawfish, and of course bluegill." He also talks about 25-30% of the fish being over the magic 16".
There are lots of conflicting opinions on here, so read up. My personal opinion is that it's not an "or" type of question. If you want huge bass in a 3-4 acre pond it's going to require management (including harvest), but the forage question between shiners and shad is an AND question, just a matter of timing and when. TShad are phenomenal, and in the early stages probably a better choice, depending upon how warm it stays where you're at. But for the right goals, GShad do have their place and purpose.
Here's an article from Pond Boss in 2004:
http://www.bassresource.com/fish_biology/gizzard_shad.html In addition, here's a great thread and debate on the topic from a few years ago:
http://www.pondboss.com/forums/ubbthread...ite_id=1#import
