Water accumulating at bottom of refrigerator compartment

Water & sometimes ice found beneath the deli tray. Also ice seen at back of compartment coming from slots. What can be done to resolve?

Refrigerator interior rear panel was removed and a lot of ice build up was seen in the vicinity of the evaporator coil. How can one determine if problem is with defrost heating element or activating circuit? Digital temp display showed 43 degrees in refrigerator.

Flickr: mrgijon’s Photostream