Chef Mike Stollenwerk has had a busy year. First he opened Fish, then he closed and re-opened his original BYOB Little Fish in a new location, and now he’s launched a third, and decidedly more low-key, spot: Fathom. Like many of the dining options at this end of town, it’s a bar-restaurant hybrid: The fare is restaurant-quality, but the atmosphere and decor lean more toward drinking establishment. There are raw-bar options — oysters and clams on the half – shell—but much of the seafood-centric fare is of the stick-to-your-ribs variety, like the Fathom Fries (that would be gravy fries topped with shredded crab and bits of cheese curd), which are just as intense as they sound. Fried “crab Louie,” nuggets of shredded crab salad with spicy chili mayo, is designed to soak up booze and does so nicely, while smoked marlin tacos with jalapeños and crispy shallots are a great idea done in by an inexcusably generic tortilla. But mighty Jonah crab claws swimming in a bowl of garlic butter make up for the transgression.