1. Heat oil in a 5 1/2- to 6-quart wide, heavy pot over medium. Stir in onion and fennel; cook, stirring occasionally, until soft (11-12 minutes). Stir in garlic, bay leaf, oregano, and crushed red pepper; cook, stirring, until fragrant (2 minutes). Add wine, water or clam juice-water combo, and tomatoes. Bring to a simmer; cook, covered (20 minutes).
2. Stir in mussels, pollock, and shrimp. Bring to a simmer over high heat, uncovered (2 minutes). Add squid, if using, cover pot, and cook till mussels open wide and seafood is opaque and just cooked through (about 5 minutes more). (Discard mussels that do not open.) Serve.