Thaw frozen fish. Remove skin and bones. Cut fish into 1-inch pieces. Fry bacon or salt pork in a 3-quart saucepan until crisp. Add onion and cook until tender. Add water, vegetables, catsup and seasonings except parsley. Cover and simmer 40 to 45 minutes, or until vegetables are tender. Add fish, cover and simmer about 10 minutes longer, or until fish flakes easily when tested with fork. Garnish with parsley. Serves 6.