Dugong Dugon

Threats to Dugongs vary between different populations as detailed in Marsh et al. (2011) and Hines et al. (2012). Major threats include:Incidental capture in fishing gear (e.g. gill nets), shark nets for bather protection, IUU fishing especially if meat is subsequently sold (see Pilcher et al. 2014, for a detailed rapid assessment based on questionnaires to provide information on conservation hotpots for Dugongs in 18 countries in four geographic areas: Pacific, Southeast Asia, South Asia and East Africa, with 6,153 respondents)Hunting: legal (i.e. culturally sanctioned) and illegalBoat strikes and boating activities (e.g. acoustic pollution)Damage/modification/loss of habitat caused by human settlement on coasts, shipping, trawling destructive fishing, natural processes (e.g. cyclones and tsunamis)Threats to seagrass (including untreated sewage disposal, coastal dredging and reclamation, inshore commercial trawling, agricultural pollution)Chemical pollution (e.g. oil spills and heavy metal loads)Climate change (extreme weather events and high temperatures)The major drivers for incidental capture in fishing gear and illegal hunting are poverty and declining fish stocks. Dugongs are legally protected in most of their range. However, enforcement is typically weak or non-existent. The imperative of artisanal fishers to break the law is increased by the opportunity to sell both Dugong meat (Robards and Reeves 2011) and valuable commodities such as swim bladders and shark fins (Marsh et al. 2011). Artisanal coastal and riverine fisheries are vital to the livelihoods and food security of coastal peoples, especially in the tropics (Batista et al. 2014), including most Dugong range states. On a global scale, such fisheries catch the same amount of fish for human consumption as commercial fisheries, yet employ some 25 times the number of fishers (over 12 million people; Chuenpagdee et al. 2008, Batista et al. 2014). Gill nets are significant threat to many marine mammals including dugongs (Read et al. 2006, Moore et al. 2010, Pilcher et al. 2014). Some Dugong declines coincide with the introduction of monofilament nylon gill nets (Muir and Kizka 2012). However, it is often very difficult to convince the fishers or the fisheries managers to take the capture of Dugongs seriously. When Dugong population sizes are low, their capture in fisheries is a rare event, which becomes rarer as the Dugong population declines. Coastal development represents another important driver. Significant seagrass loss leads to Dugongs having reduced food resources, delayed reproduction and starvation (Marsh et al. 2011). The impact of chemical and noise pollution on Dugongs is unquantified. (Marsh et al. 2011).

Climate change is projected to lead to altered coastal environmental condition and increases in severe tropical storms and flood events that could affect both Dugongs and their seagrass habitats exacerbating the effects of the other drivers listed above (see Marsh et al. 2011 for details).