Only marlin, among all bony fishes, can rival the bluefin tuna as the oceans’ largest predators, and none can rival it in commercial value; large fish can be worth hundreds of thousands of dollars on the Japanese market. The largest bluefin are found in summer and fall off Nova Scotia and Prince Edward Island, where food is abundant and where these endothermic (warm-blooded) giants are able to thrive in the frigid waters. A winter fishery has also developed off the mid-Atlantic coast for giant bluefin. Management of this precious resource by the international agency charged with doing so has been problematic, and stocks remain severely overfished. A Pacific species of bluefin provides anglers off southern Australia and New Zealand with action for fish almost as large. The world-record bluefin has remained unbroken since 1979, when Ken Fraser caught his 1,496-pounder off Nova Scotia.