In a large pot, bring the sauce, olives and brine, capers, EVOO and 3/4 cup water to a boil. Simmer over medium until flavors meld, about 10 minutes. Reduce the heat to low. Season the fish, add to the pot and spoon with sauce to cover. Cover and cook until the fish flakes easily with a fork, about 10 minutes. Divide the spaghetti among bowls; top with the fish, sauce and parsley.