Add oil to a soup pot over medium high heat. Add onion, red bell pepper and zucchini and saute until onion begins to turn clear. Stir in garlic, 1 tablespoon basil, 1 tablespoon parsley, and ground black pepper; cook for 1 more minute. Add crushed tomato and vegetable broth. Bring stew to a boil, then reduce to a simmer for 15 minutes or until zucchini is tender. Stir in cod and shrimp and cook for 5 more minutes or until both are cooked through. Remove stew from heat, then stir in remaining 1 tablespoon basil and 1 tablespoon parsley and serve.