Dugongs, or “sea cows,” are one of the species that play a vital role in maintaining Moreton Bay’s marine ecosystem. This dynamic region is located just east of the Queensland coast, outside of present-day Meanjin/Brisbane. These gentle giants can spend up to 20 hours a day grazing on seagrass. Now, during their reproduction season, that’s 65 kilos a day on average, and they’re eating that! Yet, their populations are at risk like never before, as climate change and infectious disease are causing unprecedented threats. Dr. Lanyon has been one of the world’s leading dugong researchers for more than three decades. He’s adamant about the need to keep tabs on these mesmerizing creatures and their ecosystems.
Around 800 to 1,000 dugongs call the warm turquoise waters of Moreton Bay home. These fascinating creatures are a keystone species in our marine water ecosystem. They continue to have cultural and spiritual meaning for the Quandamooka people, the lands’ traditional owners. Dugongs need healthy seagrass beds to survive, particularly when giving birth and nursing. This underscores the critical need to safeguard their feeding grounds.
Dugongs’ Foraging Habits and Feeding
Dugongs rely on specialized fine hairs on their snouts to detect seagrass. This seagrass is extremely important, as it is the base of their diet. Because of this, they can essentially graze on large patches of roots, rhizomes, and leaves during their long foraging bouts. This continuous foraging is absolutely necessary to their survival, especially for the females who need the nutritional assets to nourish their young.
Because dugongs feed by uprooting seagrass, an adult dugong can consume about 65 kilograms of seagrass each day. This dietary requirement surges even more during reproduction seasons. The food that the seagrass supports directly affects the health and well-being of the newly pregnant mothers and their calves.
“Caring for the dugongs is the same as caring for our Country,” – Justin Ladbrooke-Parkin
As Justin Ladbrooke-Parkin, an elder for the Quandamooka people, put it, protecting dugong feeding grounds is essential. He stated, “We’ve always known that there’s these special areas for the dugongs and their feeding grounds. This research obviously just supports that these areas should be protected.”
Environmental Threats and Health Concerns
Sadly, dugongs are disappearing worldwide as a result of profound shifts in their habitat. Faced with extreme weather events more than ever, such as cyclones and flooding, seagrass habitats have suffered from increased episodes of dieback, a disease that decimates these habitats. Flooding events further worsen the issue by flushing various contaminants including heavy metals, pathogens, and microplastics into our waterways. Evidence from dugong populations indicates a steep drop in body condition after flooding events. This decline is particularly noticeable comparing their health to prior years.
Dr. Lanyon’s research has been documenting alarming effects on dugongs’ health. Numerous animals have shown increased concentrations of heavy metals, pesticides, microplastics, herbicides, etc. in their tissues and circulating blood. As more contaminants begin to build into the dugongs, concerns are raised about the ability for dugong populations to survive long-term in Moreton Bay.
“We looked at a panel of 18 different common antibiotics and we found that every dugong that we looked at was resistant to quite a few of the antibiotics,” – Dr. Lanyon
Dr. Lanyon has embarked on monitoring dugongs for H5N1 disease. He emphasizes that early detection is critical: “We want to detect an emerging problem, not wait until there’s a mass mortality event.”
Conservation Efforts and Future Outlook
Now, efforts to conserve dugongs are gaining momentum. With active researchers like Dr. Lanyon tagging and studying these animals as extensively, the future looks bright for these beautiful, brilliant creatures. So far, he’s tagged more than 750 individual dugongs in Moreton Bay, collecting invaluable data on their migratory patterns and health condition.
Although dugongs are pretty chill animals, they’re facing serious threats as their seagrass pastures go under the plow. Dr. Lanyon expressed concern regarding the decline of seagrass species that are essential for dugong diets: “We’re concerned because a lot of the species that are good food for dugongs and that dugongs like to feed on are becoming rarer in Moreton Bay.”
Additionally, the importance of protecting dugong habitats, which already face severe threats, should be self evident. We need to protect their feeding grounds so that these great marine mammals will be here for our children and grandchildren to enjoy. The Quandamooka people, supported by researchers and conservationists, are determined to make this a pivotal moment.
