Bring water to a boil in a saucepan and cook sausage links for three to four minutes, or until cooked enough to be chopped. Drain. Cut links into small pieces.
In a Dutch oven or large heavy-bottomed stainless steel pot, bring chicken broth, tomatoes, bay leaves, and sausage to a light boil over medium-high heat.
Meanwhile, in a separate skillet, heat oil and butter over medium heat. Add onion, celery, and green pepper, and sauté until soft and starting to caramelize, about eight minutes. Add vegetables to chicken broth mixture. Cover and bring back to a light boil. Continue cooking, covered, over medium-high heat for five minutes.
In a small bowl, whisk together flour and water. Stir flour mixture, spices, herbs, and Worcestershire sauce into chicken broth mixture, cover, and cook over high heat for 10 minutes.
Add shrimp and crab meat, reduce heat to medium and cook for five minutes. Remove from heat and discard bay leaves. Cover and let sit for five minutes before serving.
Serve over brown rice.