State wildlife authorities in Washington are investigating after a thresher shark that washed ashore near Ocean Shores was found mysteriously decapitated. Beachgoers who initially spotted the stranded shark intact on the sand reported that when they returned later that same day, its head had been severed and removed. The decapitation has dealt a major blow to marine researchers with the Washington Department of Fish and Wildlife (WDFW). Officials emphasize that stranded sharks offer rare, crucial opportunities to study pelagic species that are understudied in Pacific Northwest waters. Explaining how the missing head hinders scientific research, WDFW official Lisa Hillier noted: “A lot of the information that we get from these animals is when they’re intact… When the head’s cut off, that changes all of the measurements.…