dwindling dugongs

[Guest guest]

Dwindling dugong

When coral reefs go, so do the marine species that depend on them either

directly or indirectly. Following on the heels of two new reports that

raised concern that the world’s reefs is another that says the future looks

bleak for the world’s marine mermaids, writes TAN CHENG LI.

THE mysterious and rare dugong, the sea mammal that inspired old seafarers’

tales of mermaids, is under serious and increasing threat in most parts of

the world where it is still found.

Findings from the first global study of the enigmatic dugong, or sea cow,

indicates that rising pollution runoff from land, coastal developments, boat

traffic and fishermen’s nets are pushing the animal to the brink of

extinction.

 

The dugong, or sea cow, reproduce at a very low rate with females rarely

producing more than one calf, sometime between the age of six and 17 years

old, and failing to reproduce at all during times of food shortages. This

makes them highly vunerable to over-exploitation.

Hunting for meat, amulets and trophies may be adding to these pressures,

says a report released last month in Cartagena, Colombia.

“Throughout much of its range, the dugong has been reduced to relict

populations separated by large areas where its numbers have been greatly

reduced or where it is already extirpated,” said lead author Dr Helene

Marsh, professor of environmental science at James Cook University in

Townsville, Queensland, Australia, at the launch of the report.

She revealed that dugongs have disappeared in waters off Mauritius, the

Seychelles, western Sri Lanka, the Maldives, Japan’s Sakishima Shoto

Islands, Hong Kong’s Pearl River estuary, several islands in the Philippines

including Zambales and Cebu, and parts of Cambodia and Vietnam.

“Elsewhere, populations appear to be declining with the possible exception

of northern Australian waters and those of the Red Sea area and Arabian

Gulf. The situation in East Africa is particularly alarming and it is

possible that this will be the next place where the dugong becomes extinct

unless urgent action is taken,” said the scientist, whose study was funded

by organisations that included the United Nations Environment Programme, the

IUCN (World Conservation Union), the UN Environment Programme’s World

Conservation Monitor-ing Centre and Cooperative Research Centres Reef

Research Centre.

The threats to the animal should be of critical concern to the billions of

people who rely on the oceans for their livelihoods because the dugong is a

key indicator species.

Its decline means that the coastal environment that provides protein in the

form of fish and income in the form of tourism is also being degraded.

Even where populations appear stable or buoyant, there can be no room for

complacency, argues the report entitled The Dugong: Status Report and Action

Plans for Countries and Territories in its Range. The report gathered

information on the state of the dugong from researchers, local people,

fishermen and government officials in the 37 countries and territories where

the animal has historically been recorded.

Growing human populations across much of the dugong range is putting

pressure on the dugong’s coastal habitats where the seagrasses they feed on

are disappearing no thanks to development and pollution.

Dugongs reproduce at a very low rate with females rarely producing more than

one calf, sometime between the age of six and 17 years old, and failing to

reproduce at all during times of food shortages. This makes them highly

vulnerable to over-exploitation.

“Even under a perfect, pressure-free and pollution-free environment, a

dugong population is unlikely to grow at much more than 5% a year. Even a

slight reduction in the survival of the adults, as a result of habitat loss,

disease, hunting or incidental drowning in nets, can cause a chronic

decline,” said Tim Foresman, director of the UN Environment Pro-gramme’s

division of early warning and assessment.

To stem the decline and boost dugong numbers, the report calls for

protection of seagrass beds. In many areas of the world, seagrass beds are

being cleared for development or smothered by silt and mud as a result of

runoff from land that is caused by earth being exposed by overgrazing,

intensive agriculture and deforestation. Port developments and dredging are

causing similar problems. Climate change, with its anticipated rise in more

violent, damaging storms and flash floods, poses a new threat.

As dugongs are culturally significant to certain communities, conservation

efforts must consider local sensitivities. They are caught for meat, oil,

and other products.

Australia’s indigenous peoples consider dugong hunting to be an important

expression of their identity. The report says unless human values change

dramatically, it will be impossible to reduce human impacts on the dugong

throughout its vast range.

Once thought to be relatively sedentary, dugongs have been found to travel

up to 600km in a few days. As such, countries with dugong populations need

to strengthen conservation initiatives with neighbouring countries,

including signing and ratifying the Convention on Migratory Species, a UN

Environment Programme-linked convention, the report says.

The report highlights two optimum conservation strategies. One is to

identify areas that still support significant numbers of dugongs and, the

other, to involve local communities and jointly consider how the adverse

impacts on dugongs can be minimised and their habitat protected. Ideally,

this should be done in the context of comprehensive plans for coastal zone

management, perhaps using the dugong as a “flagship” species.

“The long-term effectiveness of these areas will depend on community support

and the maintenance of high-quality dugong habitats. This will hinge on the

capacity to control land-based inputs,” it says.

To learn more, go to www.unep.org/dewa/ water/.

 

 

 

 

_______________

Chat with friends online, try MSN Messenger: http://messenger.msn.com