The bay is ranked among the top ten dugong habitats in Australia and together with the Gulf of Carpentaria and Torres Strait is considered one of the most important areas for dugong in Queensland. Moreton Bay is the only place in Australia where dugongs gather in herds. In the past the dugongs in herds numbered in the thousands. Some herds 5 km long by 250 m wide were seen during the 1800s. In 2009, there were just between 600 and 800 remaining.