Josh and his group did exactly what we preached...he added plenty of cover for the basic food chain, fry, minnows, and small fish in shallow water...he used 'boo, Christmas trees, pallets, and brush in shallow water which helps to protect and grow the small Crappie and fish.
We pick shallow areas two different ways....to just grow fish for the lake, and also to attract Big fish to the area to harvest....the harvest areas are close to drop-offs, points, and deeper structure that large fish will use in different patterns of the year.
What you are trying to do is provide them with food and cover so they will stay in the area. We have areas in our lake that fish never leave, and they are just self contained 50 and 100 yard areas.
This allows the small Crappie handy and easy food to grow and continue the cycle of replacing fish that may be harvested.
The small dense cover will need replaced sooner, but is also easier to refresh...since it starts decaying faster, it draws zooplankton and other beginning basics of the food chain, quickly...this draws craws, and smaller fish that will use the cover, and also use it as a feeding station...this will also draw larger fish to the area!
Knowing your lake is key, and where the big fish like to suspend or hide during different Patterns....we'll put big fish cover on top of drop-offs, on the bottom of drops and down the sides of drops...we'll put cover in channels, close to boulders, pilings, fence posts, stumps, etc. Big Crappie like Bass, will use large cover for ambush points, shade, and protection....smaller cover has to be dense enough for them to hide and get lost in or large enough to slide in behind, or belly up to. We use a lot of LARGE PVC stumps, Plastic Pallets, Big Hardwood limbs, dense Trees made with Osage Orange and other hardwood...Josh was lucky enough to get a Cemetery Headstone company to donate old headstones etc....of course he had use of a Barge to really drop a lot of stuff at once...we have to make many drops with a Armada of pontoon boats and flat decks! lol
We have made freshwater reefs out of a concrete rubble base, then hundreds and hundreds of cement blocks, and thousands of 10 hole bricks (for craws).
If you can provide everything a Crappie or fish needs in a area that has plenty of depth for summer/Winter, and a good supply of yearly oxygen, then you can build a sustainable harvest area, that will continue to provide fish for recreation or harvesting throughout the year!