WASHINGTON — After more than a decade of delays, the government is moving toward allowing the sale of U.S.-raised organic fish and shellfish. But don’t expect it in the grocery store anytime soon. The Agriculture Department says it will propose standards for the farmed organic fish year this year. That means the seafood could be available in as few as two years — but only if USDA moves quickly to complete the rules and seafood companies decide to embrace them. Organic seafood would be welcome news for the increasing number of organic shoppers — and for retailers that have profited from their higher prices.