You could place the trees in deeper water, and stand them up so the tops are below the surface by 4'. Look in the archives, there's a huge structure thread. Lots of ideas there. Some fish like verticle structure, but more fish like random/horizontal structure.

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).