Dugong

Going, Going, Dugong: Save the Sea Cows

Jason Blazensky

Organism Description and Ecology
The Dugong, or as it is known by its species name the Dugong Dugon, is a marine animal that is a member of the Dugongidae family and is the only species among every genus in its family that is not extinct. The Dugong can grow up to 3 to 4 meters long and gets its nickname "The Sea Cow" from grazing on sea grasses that grow among meadows in protected coastal valleys. As Dugongs feed, the entire plant is consumed and uprooted, leaving a trail of cleared vegetation in their wake. Dugong can grow up to 900 pounds, and are genetically more similar to elephants than any other aquatic animals. Its closest aquatic relative is the sea manatee. The Dugong have round heads with tiny eyes that are located towards the top of their skull. They have a whale like tail that is used to propel them elegantly through the water as they use their fins to steer and balance themselves. Dugong can swim at 20 km/hr to avoid predators, and are said to be the basis behind the mermaid myth. Dugong can live up to 70 years old. Dugong feed on grasses from the  Potamogetonaceae and  Hydrocharitaceae families, and have been known to occasionally eat crustaceans such as crabs. The lower lip and the roof of the mouth of the Dugong have horny pads of teeth that grasp algae and vegetation and then uproot the plant from the ocean floor. As with all marine animals, the Dugong must surface to breathe in air.

Geographic and Population Changes
Dugong populations inhabit shallow, warm tropical waters from the Indian Ocean, to the coast of South and East Africa and between Western Australia and Queensland. The Dugong live in discontinuous habitats among all these areas, and their numbers have undergone steady decreases between the 1960's and 1990's. In 1960, a study of the populations of Dugong between Brisbane and Cooktown was conducted, and found that the number of Dugong decreased from 72,000 to 4,200 in 30 years. A graph of data taken in Queensland illustrates this trend of decrease.

The amount of Seagrass in this area is not nearly enough to support the 1960 population of 72,000 Dugong, and if this declination was the same in all parts of Australia, the Dugong would be listed as critically endangered, however sites such as Shark Bay and Torres Strait support larger populations, making this species endangered.

Listing and Type of Listing
The Dugong was listed as an endangered species in 1970, however they have had a recovery plan in effect since 2013 called The Action Plan for Australian Mammals (Woinarski). This recovery plan focuses on recuperating populations of Dugong in areas with severe decline as well as maintaining the abundance of Dugong in areas that are deemed stable as well as monitoring human activity to ensure continuity of stable habitats.

Causes for Listing and Main threats against continuity of existence
There are a number of reason for the drastic decline in Dugong, almost all of which are directly linked to human activity. The most severe threat to survival is due to coastal development and expansion of sea ports. This severe habitat degradation caused massive migrations, and starvation among Dugong due to loss of seagrass. Pollution has caused unsafe amounts of lead to reach the seagrass, poisoning the dugong. Moderate problems with by catch and indigenous hunting have contributed to the decline of this species. There are many other minor causes to the declination of the Dugong such as noise pollution, vessel strike and climate change.

Description of Recovery Plan
With such an extensive list of threats, wildlife biologist have had to brainstorm many approaches to make Dugong recovery a reality. The most important strategy is to better under stand how Dugong populations are distributed throughout the World. This requires extending areal surveys to track habitat and resource use. A high priority is also finding the reasons for the impact of vessel strikes and preventable forms of injury. Habitat and dietary requirements are also studied closely to track feeding and breeding areas movement corridors and large patches of seagrass distribution. This goal can also be accomplished by understanding the feeding selection and requirements of Dugong as well as understanding the seasonality of their food sources. Scientists are also trying to further develop their understanding of the Dugong's role in sea grass ecosystems. Finally, studies on genetics and technological advances in tracking in surveying will aid in placing Dugong populations into observable management areas.
Personal Action
to aid conservation and restoration efforts, the World Wildlife Fund (WWF) will let you symbolically adopt a Dugong. 85% of all of the WWF's money received is directed to conservation efforts in 100 Countries. You can choose to donate 100, 55 or 25 dollars to the cause, and in return you will receive a stuffed Dugon, a picture and many other nifty trinkets depending on the amount of money spent. Act now and save the Sea Cows!
http://gifts.worldwildlife.org/gift-center/gifts/Species-Adoptions/Dugong.aspx

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"Species Profile for Dugong (Dugong Dugon)." Species Profile for Dugong (Dugong Dugon). N.p., n.d. Web. 05 Dec. 2015.
"Dugongs, Dugong Dugon." MarineBio.org. N.p., n.d. Web. 05 Dec. 2015.