Dugong conservation in Australia, in theory and in

practice

Helene Marsh

In Australia, dugongs are subject to multiple impacts

Boat strikes

Net entanglementsHabitat loss from terrestrial runoff

HuntingBoat noise

Tools used for Protecting Dugongs in Australia

• Regulations– Closure areas– Fishing restrictions– Boat speed limits– Permits and conditions (for tourism)– Hunting protocols– Controls on terrestrial runoff

• Education• Research and monitoring

Spatial zoning in Great Barrier Reef Marine Park

Pink – no go

Green – no take – National Parks

Yellow- no commercial fishing (no netting)

Fishing Restrictions

• Dugong Protection Areas– Significant dugong

habitat areas

• Two types:– Zone A (red)

• Most set and drift nets prohibited

• Modifications for continued netting

– Zone B (yellow)• Netting allowed with

restrictions

Boating in Dugong Areas

Disturbance• interruption of normal daily

behaviour (accumulative effects)• displacement• stress

Boat strikes• injury• death

Dugongs’ Reactions to Boats

• Preliminary results:– Often move away from direction of boat– Don’t move quickly enough for fast boats– Move a certain distance away and remain

there as repeated boat passes continue– Collisions more important than habitat

displacement

Speed Limits

• Go Slow Zones– e.g. Turtle and Dugong Go Slow

Zone – Illegal to travel above planing

speed– Patrol area and give on the spot

fines– Many people still speed

• Signs• Education

Speed Limits• Transit Lanes

– Voluntary use of specified transit lanes where vessels can travel at 25 knots

– Voluntary speed limits of 10 knots outside these lanes on shallow seagrass banks

– Lanes encourage boats to use deeper water – some boaters don’t like this

– Overall community support– Still under review

• Boat ramp surveys• Rangers checking

Dugong Tourism

• Two types of tourism– Dugong watching from boats– Dugong swim tours

• Regulations in Australia– Two areas where dugong watching from

boats occurs:• Queensland – single operator• Western Australia - 3 operators in a single bay

– No permits exist for dugong swim tours (i.e. currently illegal), but there are permits for swimming with whales and dolphins

Dugong Watching From Boats

• Only one trip per day per boat, in a specified area• Boat Speed

– While approaching: <5 knots / planing when within 100m– While leaving: <5 knots when / planing when within 300m– Motor off when within 40/50 metres

• Boat Movements– No head-on approach– No herding or intercepting

• Interaction– Maximum 15 minutes per interaction (dugong within

40/50m)– End if dugong disturbed or alarmed– End if dugong moves away (do not pursue)– No swimming, diving or entering the water– No feeding or touching dugong

Hunting Protocol

• Traditional hunting defined by purpose of hunt rather than method

• Hunting only allowed for traditional inhabitants of a region(Native Title right)

• Subsistence hunting only - sale of meat or by products such as tusks and bone not allowed

• Usually only allowed to use a ‘wap’ (harpoon) –nets banned

Ensuring Sustainable Hunting

Options:– Community dugong hunting permits

• Community issued a permit and is divided between community members

– Declaring official hunting areas– Quotas

• Can be applied to individuals or community

– Community based monitoring• Managing hunting/poaching needs community

involvement

– Closed seasons• Hunting in southern Great Barrier Reef

– Bans• No permits for hunting in southern GBR region

Flood plumesFlood plumes

Almost all pollutants discharged into Great Barrier Reef region during major flood events

Estimated area of Estimated area of maximum risk from maximum risk from contaminated contaminated terrestrial runoffterrestrial runoff

•Area contains 438 inshore reefs•462 km2 of seagrass beds and large estuarine areas

Subtidal diuron (herbicide) Subtidal diuron (herbicide) concentrationsconcentrations

Diuron ranged from

<0.1-10.1 µg kg-1

Concentrated in wet tropics Diuron significantly

reduces seagrass photosynthesis

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Comparison of OCDD levels Comparison of OCDD levels in marine mammals worldwidein marine mammals worldwide

Where to from here(rehabilitation & prevention)

• Restore riparian vegetation - $US 30,000 per km2

• Restore freshwater wetlands - $US 3,500 per ha• Fence streams to prevent cattle access

– $US 150,000 for 400 km

• Tailwater capture for irrigated cropping• Closed cycle aquaculture• Ban some pesticides• Management of fertilizer use

Progress in 2002

• MOU between Prime Minister and Qld Premier to address the issue

• “No regrets” policy – implement what stakeholders agree on

• Then move to address next issue

Education

• Training Courses– e.g. Endangered species awareness

course (Fishing Industry Training Council)• Encouraged as a prerequisite for holding

a commercial net fishing licence

• Brochures– e.g. Transit Lanes

• Signs– e.g. Boat ramps in Dugong Protection

areas

Research and Monitoring

• Distribution and abundance– Aerial surveys to monitor distribution and estimate

abundance• Identify important habitats • Estimate sustainable catch quotas

• Satellite tracking to study movements and fine scale habitat use

• Genetic study on relationship between stocks in Australia and South East Asia

• Impacts of boats• Effects of terrestrial runoff on seagrass as food

for dugongs

Conclusions

• Multiple impacts need a ‘toolbox’ of approaches to ensure conservation

• Need to involve community

Lessons for Vietnam• Identify areas that still support

significant numbers of dugongs

• Consider with extensive local involvement how dugong mortality can be minimised and their habitat protected

• If possible, protect dugongs in the context of comprehensive plans for coastal zone management using the dugong as a flagship species