A leading WA research scientist says a massive blue marlin that washed up at Middleton Beach likely died because it spent too long in the cooler waters off WA’s south coast. Albany beachgoers were met with a fishy surprise last Thursday morning when a 3.8m long, 280kg blue marlin was found washed up at Middleton Beach near Griffiths Street. Department of Primary Industries and Regional Development principal research scientist Gary Jackson said tissue samples were sent to Queensland for analysis. Though the fish was initially described by authorities as a black marlin, Dr Jackson said it was a female blue marlin. A brief autopsy conducted by an Albany DPIRD officer last Thursday found no obvious signs of trauma, net marks or hook wounds. The marlin’s gills appeared normal and its stomach was empty. Dr Jackson said blue marlin washing up on the south coast of Australia was a “rare event”. “Blue marlin are tropical species that are more likely to be found further north near Abrolhos to Broome, but in some years can be found further south, between Rottnest and Capes at certain times of year,” he said. “These species of fish do move down the west coast seasonally each year, taking advantage of warm water offshore current ... In the absence of full autopsy and the strong cold fronts and rough sea conditions off the south coast at this time of year, it is likely that this fish died of natural causes when it found itself in cooler water inshore that would have caused significant physiological stress,” he said. Several blue marlin washed up in the Albany area between 2013 and 2015 following a marine heatwave. A blue marlin that washed ashore at Little Beach in June 2013 was believed to be the biggest recorded in Australia at 540kg.