Thaw fish, if frozen. Rinse fish; pat dry with paper towels. Measure thickness of fish; set aside. In a small bowl combine pecans, bread crumbs, butter, lemon peel, the 1 tablespoon parsley, the salt, black pepper, cayenne pepper, and garlic. Set aside.
For a charcoal grill, grill fish, skin sides down, on the greased rack of an uncovered grill directly over medium coals. Spoon the pecan mixture on top of fillets; spread slightly. Grill until fish begins to flake when tested with a fork. Allow 4 to 6 minutes per 1/2-inch thickness of fish. (For a gas grill, preheat grill. Reduce heat to medium. Place fish on greased grill rack over heat. Spoon pecan mixture on top of fillets. Cover and grill as directed.) If desired, sprinkle fish with additional snipped parsley and serve with lemon wedges.