Dugong By: Elliot Hangos

  • Scientific Name: Dugong dugon
  • Common Name: Dugong
  • Nickname: Sea Cow

The Dugong became listed on the IUCN Red List of Threatened Species, due to the following: gill netting, subsistence hunting, habitat loss from extreme weather events that are likely to be exacerbated by climate change, human settlement, and agricultural pollution. It has been listed on, and off, the Red List since 1982.

Direct results of gill netting, agricultural pollution, and habitat loss

Timeline:

  • 2008 – Vulnerable (VU)
  • 2006 – Vulnerable (VU)
  • 1996 – Vulnerable (VU)
  • 1994 – Vulnerable (V)
  • 1990 – Vulnerable (V)
  • 1988 – Vulnerable (V)
  • 1986 – Vulnerable (V)
  • 1982 – Vulnerable (V)

Geographic Range:

Dugongs inhabit coastal and island waters ranging from East Africa to Vanuatu

Major Threats:

  • Threats to Dugongs vary between different populations, but major threats include:
  • Incidental capture in fishing gear (gill nets)
  • IUU (Illegal, Unreported, and Unregulated) fishing especially if meat is subsequently sold
  • Hunting
  • Boat strikes and boating activities
  • Damage/modification/loss of habitat caused by human settlement on coasts, shipping, trawling destructive fishing, natural processes (cyclones and tsunamis)
  • Threats to seagrass (including untreated sewage disposal, coastal dredging and reclamation, inshore commercial trawling, and agricultural pollution)
  • Chemical pollution (oil spills)
  • Climate change (extreme weather events and high temperatures)
Major Threats to Dugongs

Population:

The current population of Dugongs is about 40,000 and that number is continuing to decline, mostly due to their very slow reproduction rate. Severe weather along the coast of Australia which has greatly damaged the Great Barrier Reef, which is where the highest population of Dugong's live. There has also been a drop in the amount of seagrass feeding grounds in the past couple of years which has also lead to the endangerment of Dugongs.

Ecosystem and Biodiversity:

Dugong's require coastal areas, shallow to medium deep, warm waters, and seagrass beds. They are particularly low fiber species. Dugongs show great variability in movement patterns and migration, depending on the study area and the influence of seasonal temperature or rainfall on regional ecosystems. There are many long-distance movements by Dugongs along the Queensland coast that have been well-documented, even though Dugongs do not appear to undertake regular migrations and individual movements are individualistic. They live in Marine systems, generally shallow waters, and there movements resemble a nomadic lifestyle.

Dugong's play an important ecological role in coastal marine ecosystems, and the status of Dugong populations in an area can be used as an indicator of general ecosystem health. Their intense grazing of seagrass beds contributes to nutrient cycling and energy flow as they stir up sediment. Their fecal matter also acts as a fertilizer, which helps seagrass to quickly replenish. However, this intense grazing also reduces habitats and nurseries for important commercial fish species and other invertebrates which live in seagrass beds.

Dugong feeding on seagrass

Conservation Actions:

Dugongs are covered under three international conservation conventions: The Convention on Biological Diversity (CBD), the Convention on the International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the Convention on Migratory Species of Wild Animals (CMS). Dugongs are also included in the Coral Triangle Initiative (CTI), goal five (Threatened Species). Additionally, the Convention on Wetlands (the Ramsar Convention) protects some important Dugong habitats. Some protected sites for Dugongs have been established, particularly off the coast of Australia. These areas contain seagrass beds and optimal environments for Dugongs, such as shallow water and areas in which to give birth.

Bibliograhy

  • Marsh, H. & Sobtzick, S. 2015. Dugong dugon. The IUCN Red List of Threatened Species 2015: e.T6909A43792211. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T6909A43792211.en. Downloaded on 04 January 2017.
  • Marsh, Helene. "Aerial Survey Shows Dugong Decline." Aerial Survey Shows Dugong Decline | NERP Tropical Ecosystems Hub. National Environmental Research Program, 2012. Web. 04 Jan. 2017.
  • "Working Together Today for a Healthier Reef Tomorrow..." Dugong - GBRMPA. Great Barrier Reef Marine Park Authority, 2016. Web. 04 Jan. 2017.

Credits:

Created with images by PublicDomainImages - "manatee underwater sea" • Ruth and Dave - "Dugong in sea grass meadow, Marsa Abu Dabbab"

Made with Adobe Slate

Make your words and images move.

Get Slate

Report Abuse

If you feel that this video content violates the Adobe Terms of Use, you may report this content by filling out this quick form.

To report a Copyright Violation, please follow Section 17 in the Terms of Use.