BRISBANE GOLD COAST - Department of State … COAST STRA SESSMENT 8-4 8 - The total area within the GBRWHA predicted to be of conservation value for dugong were 2399 square kilometres

BRISBANE

GOLD COAST

Relevance to Program

Program Component MNES and OUV

Type of activity Overall effectiveness

Effectiveness of threatened species management

Coastal Protection and Management Act 1995Environmental Protection Act 1994Fisheries Act 1994Dugong protection areasMarine Parks Act 2004Great Barrier Reef Coast Marine Park Zoning Plan 2004Native Title (Queensland) Act 1993Nature Conservation Act 1992State Development and Public Works Organisation Act 1971Sustainable Planning Act 2009Transport Operations (Marine Pollution) Act 1995Water Act 2000Reef Water Quality Protection Plan

Migratory speciesWHA/OUV/GBRMP

All Partially effectiveOverall, management is partially effective at minimising impacts. Even low levels of incidental capture or impacts on seagrass has a significant impact on the ability for dugongs to recover from severe weather events

1.1 Introduction and purpose ...........................................................2

1.2 Identification of Matters of National Environmental

Significance ............................................................................... 3

1.3 Pressures and potential impacts .............................................. 6

1.4 Measures to avoid, mitigate and offset impact on MNES ........12

1.5 Measures to enhance MNES ................................................... 16

1.6 Information gaps and how they are being addressed ..............17

1.7 Program effectiveness ............................................................. 19

Demonstration Case 8: Dugong Management

GREAT BARRIER REEF COASTAL ZONE STRATEGIC ASSESSMENTDemonstration Case 8-2

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1.1 Introduction and purpose

The purpose of the demonstration case is to assess in finer detail the effectiveness of the Program to protect and manage dugongs as a matter of national environmental significance (MNES), identify any gaps and guide improvements to the Program.Dugongs were chosen as a joint demonstration case because of significance of the species to the outstanding universal value (OUV) of the Great Barrier Reef World Heritage Area (GBRWHA), the conservation status of the species and the availability of scientific information to inform a detailed assessment.The information provided here is an extract from the Dugong Technical Report produced by the Queensland Government and the GBRMPA.The GBRWHA is home to a globally significant population of dugongs, which was one of the reasons it was inscribed on the World Heritage List in 1981. Specifically, dugongs and seagrass contribute to the recognition of the Reef’s outstanding universal value for three of the four natural criteria for World Heritage listing: significant geomorphic features, significant ongoing ecological and biological processes, and significant natural habitats for the conservation of biological diversity.Dugongs are of great cultural, spiritual and social importance, especially to the Reef’s Traditional Owners who report ‘the old people remember more animals’ than are present today. These large marine mammals are a matter of national environmental significance as a listed migratory species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), and are also listed as a marine species under that Act. Dugongs are listed as vulnerable under the Nature Conservation Act 1992 (Qld) and as a protected species under the Great Barrier Reef Marine Park Regulations 1983.Dugongs are found in the coastal waters of more than 40 countries and territories, but their status is either declining, locally extinct, or unknown throughout most of their range. Australia’s northern waters (from Moreton Bay in southern Queensland to Shark Bay in Western Australia) contain approximately one quarter of the world’s dugong habitats, and will probably be their last stronghold. Australia is the only developed country with a significant dugong population and it has the most extensive coastline at relatively low risk from coastal development.Dugongs inhabit predominately shallow inshore waters where they are exposed to a number of impacts. Dugongs spend 72 per cent of their time on average in less than three metres of water, dive on average 12 times an hour and feed up to 16 hours per day. Shallow waters, such as on tidal sandbanks and estuaries, have been reported as sites for calving. At the higher latitudinal limits to their range, deeper waters may be used as a thermal refuge from cooler inshore waters.

1.2 Identification of Matters of National Environmental Significance

1.2.1 Monitoring of dugongs

Direct monitoring of the distribution and abundance of dugongs in Australian waters using aerial surveys along the Queensland coast by James Cook University commenced in 1985, and has generally continued on about a five yearly basis depending on available funding. Aerial surveys using standard techniques have provided much of the information used to monitor and manage dugongs in the GBRWHA.The statistical power of the current time-series of aerial surveys is not high enough to detect a slow rate of decline. A cost-benefit analysis recommended that surveys be conducted at large spatial scales and at a minimum of five-year intervals, to minimise spatial and temporal errors, respectively. Improving the power to detect declines in the dugong population would depend on very substantially increasing survey extent and frequency, or developing different techniques for monitoring as scientific understanding and technology improve into the future. Nevertheless current techniques for monitoring dugong populations provide some of the most valuable and robust management information available for any species in the GBRWHA.Sources of dugong mortality or morbidity are monitored through the Queensland Marine Wildlife Mortality and Strandings Program, which is operated jointly by the Queensland Government and the Great Barrier Reef Marine Park Field Management program. The program provides information in an Annual Report on dugong condition and disease status. The previous Queensland Fisheries Observer Program also provided critical independent fishery data on mortality of dugong and other key species.

1.2.2 Dugong distribution and relative abundance

Information from aerial surveys and seagrass surveys were used to identify 31 important dugong habitat sites for the Representative Areas Program (where dugongs could be regularly found or identified habitats where dugongs could be expected to be found). Subsequently, hotspots of high relative dugong abundance have been modelled and mapped. The map (Figure 1) depicts where dugongs are most abundant at the scale of the World Heritage area. The model takes account of the large scale dugong movements that occur due to changes in seagrass habitats because it is based on integrated data from six aerial surveys spanning 19 years along the urban coast and three surveys of the remote Cape York region conducted over a decade.


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Figure 1 Model of dugong distribution and relative abundance


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The total area within the GBRWHA predicted to be of conservation value for dugong were 2399 square kilometres of high value, 2175 square kilometres of medium value and 27 490 square kilometres of low value. The remote Cape York region had the greatest proportion of high (2226 km2; 93 per cent), medium (1916 km2; 88 per cent) and low (15 719 km2; 57 per cent) conservation value areas for dugongs. Dugongs also occur at very low densities along the entire protected inshore waters of the GBRWHA.The following areas are considered to be of particularly high conservation value to dugongs in the GBRWHA north of Cooktown: ▪ Shelburne Bay region ▪ Temple Bay region ▪ Lloyd Bay (Lockhart River) region ▪ Friendly Point region ▪ Port Stewart regions ▪ Bathurst Bay ▪ Starke region between Barrow Point and Lookout Point

The following areas are considered to be of particularly high conservation value to dugongs in the GBRWHA south of Cooktown: ▪ North of Hinchinbrook Island ▪ Cleveland Bay ▪ Shoalwater Bay including Port Clinton

Medium and low density areas are also important, because connectivity (habitat, population and genetic) between areas of high conservation value dugong habitat is important for long-term population sustainability.Evidence suggests significant large-scale movements of dugongs happen, probably in response to changes to seagrass meadows, which can vary across bathymetric, nutritional and seasonal gradients, and are subject to large-scale periodic diebacks.Individuals have been tracked from Hervey Bay (south of the GBRWHA) to Shoalwater Bay, and from Hinchinbrook Island to Princess Charlotte Bay, around 560 kilometres north. Despite this capacity for longdistance movement, it is emerging that some genetic structure exists, albeit at large spatial scales (which may be indicative of limits to population migration or a consequence of population bottlenecks).

1.3 Pressures and potential impacts

1.3.1 Pressures

Dugongs feed almost exclusively on seagrass and they must consume large quantities each day to fulfil their energy requirements. The dugong’s preference for inhabiting inshore areas exposes them to a range of human-related marine and land-based activities. These activities include climate change and extreme weather, urban development, industrial development, agriculture, ports, shipping, defence activities, research studies, traditional use, recreation, fishing and tourism (Figure 2).Currently, the greatest impacts on dugong populations in the GBRWHA are habitat loss and degradation from: ▪ cyclone activity and extreme weather ▪ nutrients, pesticides and sediment from catchment run-off ▪ clearing or modifying of coastal habitats ▪ coastal reclamation ▪ direct impacts of dredging ▪ dumping and resuspension of dredge material.

Dugongs are also affected directly by disease, the incidental capture in nets (death of discarded species from the commercial net fishery and the Queensland shark control program), vessel strike, illegal fishing and poaching, and harvest of dugong (hunting for traditional use) to varying degrees.Commercial hunting, which began in Queensland in 1847, took a significant toll on the species, particularly south of Cooktown, where virtually all of the operations were based. Harvesting was banned completely statewide in 1969. The introduction and widespread use of monofilament fishing nets from about the 1960s also resulted in a significant incidental capture of dugong, prompting the progressive introduction of Dugong Protection Areas, coastal zoning and changes to net designs. Despite management actions to protect them, dugong population numbers in the GBRWHA south of Cooktown have not rebounded. As long-lived slow breeding animals, dugongs have slow rates of recovery from population declines. Survival of adult dugongs must be more than 90 per cent each year to maintain a population. Population simulations based on adult survival estimates from manatees (the most closely related group of species) and empirical reproductive data from dugongs in the Torres Strait estimate the maximum population growth rate to be about one to six per cent annually.


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Figure 1 Model of dugong distribution and relative abundance Source: WTMA, 2013

1.3.2 Cyclone activity and freshwater

influx from flooding

Cyclones are a natural part of the weather cycle in tropical areas and have been for millennia. Cyclones are also associated with heavy or prolonged rainfall and flood events. Six severe cyclones have impacted the GBR since 2005, and the majority of the GBRWHA has been affected by damaging winds and waves within the last decade. The combined paths of these cyclones have exposed 80 per cent of the GBR Marine Park to gale force winds or above; of this area 33 per cent and 38 per cent were exposed to destructive or very destructive wind speeds respectively. Most of the Region is likely to have experienced damaging waves at least once during the last decade and the area between Cairns and Townsville has been particularly affected.Much of the inshore area of the GBRWHA has also been exposed to significant increases in freshwater influx resulting from high levels of rainfall. Freshwater influx to the marine environment from heavy or prolonged rainfall and flood events can reduce salinity and have a range of effects on marine life. Freshwater influx in the absence of cyclones occurs seasonally, and is generally higher in the southern half of the Region, corresponding with the larger catchments.

Activities such as agriculture, urbanisation and industrial development can increase the volume and timing of freshwater inflows into the Region. For example, roads, stormwater drains and other urban infrastructure can increase the volume and speed of freshwater inflow compared to natural vegetation and soil which retard water movement.

1.3.3 Impacts on water quality

Development in the catchment and on the coast, and the increasing human population along the Queensland coast are directly linked to coastal habitat degradation, groundwater discharge and replenishment, discharge of nutrients, sediment and pollutants onto the inshore habitats and a significant reduction of water quality (increased turbidity) in these areas, which affect seagrass meadows.Since European settlement, there have been significant losses of and modifications to the terrestrial habitats that support the GBR ecosystem. Previous broad scale land clearing, principally in the southern two-thirds of the GBR catchment, has indirectly caused major changes to the Region’s environment habitats and species.


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Habitats have been most substantially modified in southern areas of the catchment, especially saltmarshes, wetlands, woodlands and forests. There has also been grazing on Cape York, but mostly of native pasture in open forest and woodlands, and much less clearing than in southern areas.Terrestrial habitats in the adjacent coastal zone support the GBR ecosystem in a variety of ways. These include slowing and filtering the overland flow of water; trapping nutrients and sediments; binding and stabilising soils and preventing erosion.In brief, the loss of ecosystem services provided by catchment and coastal habitats provide to the GBR ecosystem have flow-on effects on nutrient cycles, terrestrial and marine connectivity and biodiversity. Changes to the environment have impacted on levels of freshwater entering the lagoon and on groundwater discharge and replenishment. The loss and modification of habitats has led to significant increases in pollutants, principally nutrients and sediments, entering the GBR lagoon especially in southern inshore areas.Dugongs feed almost exclusively on seagrass. Impacts such as increased sediments, nutrients and pesticides indirectly impact on dugongs through their consequential effects on seagrass. Seagrass ecosystems are very sensitive to human influence.

1.3.3.1 Nutrients in catchment run-offThe changes in land use that have occurred since European settlement have significantly altered nutrient concentrations in the inshore waters of the GBR lagoon to the extent that it is recognised as the most serious factor affecting the health of the GBR. Once dissolved inorganic nutrients enter the marine system, they are taken up by organisms including seagrasses.However, elevated concentrations can lead to eutrophication which is detrimental to seagrass health and resilience. Lowered ambient light levels, as a result of increased growth of phytoplankton, macroalgae and algal epiphytes that compete for light, reduce photosynthesis, impeding growth.

1.3.3.2 Sediment in catchment run-offIncreases in suspended sediment significantly lower light levels which reduces photosynthesis. As the increased sediment load settles, it can smother seagrass making it harder or impossible for them to grow, survive and reproduce. Halophila ovalis, one of the preferred food species of dugongs, is particularly sensitive to light reduction; it declines rapidly and recovers slowly, with a complete die-off occurring after 30 days of light deprivation.Sediments are mostly transported to the GBRWHA via coastal rivers during the wet season. It is estimated that since European settlement of the catchment area in the 1850’s, the average annual suspended sediment load entering the GBR has

increased by 5.5 times to 17 000 kilotonnes per year, with some catchments as high as fourteen times more. This is mainly due to increased soil erosion where areas have been cleared of native vegetation to establish pasture grasses for grazing, exacerbated by loss of ground cover. Much of the inshore southern area of the GBRWHA is frequently affected by increased sediment that often exceeds Water Quality Guidelines. Most of the coarser-grained sediment settles out of the water column within five to fifteen kilometres of the coastline and is confined to the inner shelf. However, the finer fraction of suspended sediment may be carried further offshore, especially during flood events, where it may be resuspended later by wind-generated waves and currents. These fine colloidal sediments also carry nutrients and other contaminants further into the GBR Marine Park.

1.3.3.3 Pesticides (including herbicides) in catchment run-offIt is estimated that at least 30 000 kilograms of herbicides are now exported to the GBRWHA each year. Recently, more systematic monitoring of pesticide residues, has shown widespread contamination by a range of pesticides in rivers, streams and estuaries draining to the Region, particularly areas south of Port Douglas. The most frequently detected pesticides in inshore waters include those that inhibit the photosynthetic pathway (PS-II) of plants in an additive manner: the PS-II herbicides diuron, atrazine, hexazinone, simazine and tebuthiuron.The studies conducted on seagrass have indicated that these PS-II herbicides may have lasting effects on photosynthesis but the extent to which this translates into reducing seagrass growth is unclear. In flood waters close to the coast, herbicides including atrazine and diuron have been detected at levels that exceed the Australian and New Zealand Water Quality Guidelines for fresh waters (up to 10 to 50 times).The Mackay-Whitsunday Region, lower Burdekin and waters between Cairns and Cardwell are of the greatest concern for exposure to pesticides. In addition to catchment run-off, herbicides from ports, shipping and boating activities may also exert an impact in the marine environment. The environmental consequence for seagrass are unknown, but a toxic response by two seagrass species (H. ovalis and H. spinulosa) have been detected in laboratory studies, and these are species that are eaten by dugongs.


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1.3.3.4 Urban and industrial dischargeIndustrial and urban development has resulted in impacts on water quality discharged into the lagoon. This includes pollutants in sewage, and permitted and unpermitted effluent from the industrial and mining activities into waterways (for example from discharges of effluents or failure of a tailing pond) in the course of major rainfall or flood events. On islands the effects of sewerage outfalls from the resort and amenities have had an effect on the Region’s seagrass.Studies have found elevated concentrations of some contaminants in dugongs along the Queensland coast. Studies on other marine mammals have demonstrated detrimental impacts to their health and reproductive success as a result of the bioaccumulation of toxins. However, the levels in dugongs were low in comparison to other marine mammals examined around the world.While knowledge of resultant health and physiological effects on dugongs is very limited, a risk assessment found a high potential for adverse health effects from specific organochlorine pollutants (e.g. dioxins). Exposure to toxicants may also result in a lowered immune response and other secondary health effects. Compared to diffuse sources most contributions to suspended sediment, nutrient and pesticide loads from point sources such as intensive animal production, manufacturing and industrial processing, mining rural and urban residences, waste treatment and disposal, ports and shipping are relatively small but could be locally and over sore time periods highly significant.

1.3.4 Coastal reclamation

Coastal reclamation refers to the process of creating new land where there was ocean, wetlands, or other water bodies by filling the area with ‘land fill’ or infrastructure such as groynes and jetties. Reclamation projects can be for public open space, housing or commercial and industrial developments. About one per cent of the Region’s coastline has been directly affected by reclamations, groynes and jetties. The largest coastal reclamation projects have been for the development of ports, particularly in Townsville, Mackay and Gladstone.Coastal reclamation can have local effects on the Region’s environment, for example it can alter smallscale currents; result in the removal of coastal habitats, impede natural drainage from the catchments, and alter groundwater levels. If not properly managed, it can affect water quality in the adjacent waters and potentially expose acid sulphate soils. Direct removal of seagrasses has occurred during port infrastructure development

and coastal development. Port developments and marina infrastructure are closely managed and generally the area of seagrass lost is small at the Reef-wide scale, although may be significant in individual bays.

1.3.5 Dredging

Dredging involves the extraction of parts of the seafloor (predominantly sand and fine silt, but also harder substrate such as coral reef flats) to deepen an area and allow increased access. It is usually associated with ports, shipping channels, marinas and boat ramps. Capital dredging is that undertaken to create, lengthen, widen or deepen existing channels, berth areas, swing basins, marinas and boat harbour areas. Maintenance dredging is that undertaken to ensure that previously dredged depths are maintained. Both capital and maintenance dredging is undertaken within and adjacent to the Region. Proposals currently under assessment (as at 30 May 2013) involve approximately 54 million cubic metres of dredging in the World Heritage Area.Dredging may lead to direct removal of seagrasses and to increased turbidity from disturbed sediments. Turbidity principally affects organisms that photosynthesise, including seagrass by reducing the amount of available light. Dredging may also disturb dugongs because of increased activity and noise in inshore areas in which they forage. Dredging can expose acid-sulphate soils and other toxic compounds and when disposed of within marine environments spoil can be exposed to re-suspension during high wind and/or tide conditions.Once material is extracted from the seafloor via dredging, it requires disposal. Each port or marina has individual dredge disposal requirements depending on its location and operations. Dredge material is often disposed in specified placement sites in the ocean, just offshore from the ports.

1.3.6 Incidental death

Although StrandNet has systematically recorded dugong strandings from Cairns to the Queensland–New South Wales border since 1996, coverage is less comprehensive in sparsely populated areas of the Gulf of Carpentaria, Torres Strait and eastern Cape York Peninsula. It is acknowledged that the stranding data reported to StrandNet will at best represent only a proportion of carcasses and injured dugong occurring in these waters, and as discussed above StrandNet does not include comprehensive reporting of dugong taken illegally (poached).


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1.3.6.1 Incidental capture in nets Accidental entanglement in large mesh nets (or traps) set by fishers (legal and illegal) is a widely known but largely unquantified cause of dugong mortality in all countries within the dugong’s range, including Australia. As air breathing mammals, dugongs can drown within minutes of becoming entangled in a net. For example, in 2010 there were nine confirmed dugong deaths and three unconfirmed deaths attributed to entanglement in nets in the Queensland Marine Wildlife Strandings and Mortality Program (and StrandNet database). There were also three reports of dugong released alive from nets. In 2011, there were three suspected mortalities from fisheries entanglement and one that was released alive. Two dugongs also died after being entangled in Shark Control Program nets.

1.3.6.2 Vessel strike on wildlifeVessel strike (vessel collision) is a documented cause of dugong injury and mortality (Queensland Marine Wildlife Strandings and Mortality Database). Dugongs may be seriously injured by vessel hulls if struck at high speed and cuts caused by propellers may cause death or lead to serious infection or disability. Between 1996 and 2010 there were 44 documented dugong deaths due to vessel strikes within the World Heritage Area reported in the Queensland Marine Wildlife Strandings and Mortality Database.

1.3.7 Sub-lethal or chronic impacts

It is extremely difficult to assess the extent to which a particular sub-lethal impact including disturbance, noise, and pollution will affect, or is affecting, individual animals or a population. Possible effects of sub-lethal impacts on dugongs may include:• Behavioural modification, such as:

- Changing swimming speed or direction - Changing dive depths or durations - Changing breathing rates - Changing or ceasing particular activities (e.g. feeding) - Leaving an area

• Susceptibility to disease• Reduced reproductive success.

1.3.7.1 Disturbance of wildlife (other than noise)An example of sub-lethal impact that has been studied in dugongs is behavioural disturbance from boating traffic. In addition to vessel strike (described above), boats and other vessels may also disturb dugong behaviours such as feeding, or result in an avoidance response, particularly if they are within a

distance of approximately 50 metres. Feeding interruptions cause by passing vessels are relatively short, but examining the longterm biological consequences of disturbance requires a more integrative approach that considers aspects such as how often marine mammals are disturbed and how they may compensate for disturbance. In a study in Moreton Bay it was estimated that the level of vessel disturbance they observed caused a maximum of 0.8 to 6 per cent reduction in the time spent feeding by dugongs.However, this level of disturbance corresponded to the boating traffic that was observed at the study site in 2001- 02, and more frequent boating traffic may translate to population level impacts. Anecdotal evidence of dugong displacement also comes from persistent reports from Indigenous hunters that dugong distribution has changed in response to vessel traffic in Torres Strait.

1.3.7.2 Noise pollutionIncreasing shipping and boating activity, the use of sonar, coastal development including pile driving, and defence activities all contribute to increased underwater noise. Sound is extremely important to many marine animals, playing a role in communication, navigation, feeding, orientation and the detection of predators. Concerns about the impacts of anthropogenic sound on marine animals has grown over recent decades and is now considered a significant stressor for marine life worldwide. Sounds can have a range of effects on marine life depending on the acoustic frequency animals are able to detect and produce and their proximity to the source. Effects to marine life range from detection with no adverse impacts, to significant behavioural changes, or hearing loss, physical injury or mortality.

1.3.7.3 Pollution and chemical and oil spillsAlthough causal relationships have not been established, the near-shore and estuarine environments inhabited by dugongs expose them to chemical pollution, waste disposal, leaks/leaching and spills during maritime operations and ship maintenance. Although dugongs occur in areas that are also important shipping lanes, there is no information about dugongs being impacted by oil spills in the GBRWHA. Limited information from overseas indicates that dugongs are vulnerable to this impact.Coal dust is the primary air pollutant emitted at coal terminals and can occur anywhere coal is handled, conveyed or open to erosion by the wind. Coal dust tends to float and remain on the water’s surface, and in sufficient volumes could potentially block sunlight for seagrasses. Likewise, coal dust particles can also aggregate and settle, potentially smothering seagrass meadows. Possible anoxic conditions that might arise during coal oxidation within very close proximity (0–100 m) to the coal-loading terminal.


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Trace elements can leach from coal particles into seawater — some of major concern include arsenic, mercury, lead, sulphur and boron. However, Australian coal has relatively low concentrations of trace elements compared to other coal reserves. There is no information on whether these elements are present in the World Heritage Area as a result of coal stock piles or port activity. Contamination of groundwater entering the marine ecosystem may have negative consequences on flora and fauna. The connectivity between ground water and the ocean is poorly understood, but submarine freshwater springs on the seabed (wonky holes) are known in the GBR. Seagrass may be part of or adjacent to ground-water dependent ecosystems.

1.3.7.4 Marine debrisThe northern GBR receives a northward flow of litter from land-based sources that congregates towards Cape York Peninsula and appears to remain contained within the Reef’s lagoon. Dugongs may have a limited ability to detect and avoid effects from marine debris, given their poor eyesight and feeding behaviour. Dugongs examined as part of the Marine Wildlife Stranding Program have been found with ingested fishing hooks and may become entangled in synthetic material.

1.3.8 Consideration of cumulative impacts

Commonly, individual impacts affecting dugongs in the GBRWHA vary in severity, spatially and/or over time (perhaps seasonally or simply accumulating as a function of time). Impacts can be acute and direct (such as mortality from boat strike), or chronic indirect impacts (leading to declining water quality and loss of seagrass).The effects of individual impacts may or may not seem significant but the cumulative effect of successive, combined and interactive impacts are of significant concern for the conservation and management of dugongs in the GBRWHA. Cumulative impacts take into account the direct, indirect and consequential impacts and the incremental and interacting effects of these impacts over time. The effects of several impacts acting consecutively or simultaneously is likely to be significant, but is poorly understood.Specific challenges in assessing cumulative impacts on dugongs in the GBRWHA directly (and indirectly through impacts on seagrass) include: ▪ the sheer number of drivers, activities and impacts acting on

dugongs and seagrass meadows ▪ limited understanding of the relationships between

ecological and human systems

▪ the multiple scales at which processes and impacts occur and interact with ecological and human systems

▪ limited understanding of the interactions or ‘compounding’ impacts on dugongs and seagrass meadows

▪ the dynamic nature of systems and the rapid pace of change.

The areas of highest exposure to cumulative impacts are inshore areas, particularly in the southern two thirds of the Region. Cumulative impacts have caused habitat loss and degradation of seagrass meadows as evidenced by: ▪ major loss of area and abundance of seagrasses in recent

years (i.e. poor condition), ▪ low reproductive capacity (loss of seed banks within the

meadows) ▪ high tissue nutrient levels (indicating reduced growth due to

eutrophic conditions) ▪ loss of species diversity and a dominance of rapid growing

species over habitat forming species of seagrass, ▪ presumed loss of connectivity between seagrass meadows,

and the probable loss of genetic diversity.Some or all of these consequences over time, together with other impacts have influenced the condition and trend of dugong populations in the GBRWHA.


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1.4 Measures to avoid, mitigate and offset impacts on MNES

1.4.1 Applicable Queensland legislation

Queensland Government Program components that are applicabale to the protection of and management of dugongs in the GBRWHA are: ▪ Coastal Protection and Management Act 1995 ▪ Environmental Protection Act 1994 ▪ Fisheries Act 1994 ▪ Nature Conservation Act 1992 ▪ Marine Parks Act 2004 ▪ Great Barrier Reef Coast Marine Park Zoning Plan 2004 ▪ Local Government Act 1993 ▪ Native Title (Queensland) Act 1993 ▪ State Development and Public Works Organisation Act 1971 ▪ Sustainable Planning Act 2009 ▪ Transport Operations (Marine Pollution) Act 1995 ▪ Transport Operations (Marine Safety) Act 1994 ▪ Transport Infrastructure Act 1994 ▪ Vegetation Management Act 1999 ▪ Water Act 2000

1.4.2 Management activities

Dugongs have been a focus of management agencies for many decades, with high level leadership from the former Great Barrier Reef Ministerial Council. In the 1980s, the GBRMPA’s original zoning plans protected some important dugong habitats (seagrass meadows) in Marine National Park Zones and Preservation Zones. The level of spatial protection was increased significantly in 1997 in response to the long-term decline in the dugong population south of Cooktown and the ongoing and unsustainable levels of interactions between dugongs and fishing nets and shark control nets. These emergency measures established 16 Dugong Protection Areas under Queensland fisheries legislation (which imposed spatial and fishing gear restrictions and prohibited the use of some types of fishing nets).

Soon after, additional measures to protect seagrass habitats from trawling were introduced, as well as netting restrictions and net attendance rules to reduce the incidental capture of dugong within the East Coast Inshore Fin Fish Fishery. The use of nets in the Queensland Shark Control Program was also reviewed and modified. Other management arrangements were introduced by the Department of Defence for activities in the Shoalwater Bay Defence Training Area. While there is limited traditional hunting of dugong as a native title right, some Traditional Owner clans have voluntarily imposed low levels of hunting under Traditional Use of Marine Resources Agreements, with some clans choosing not to hunt this species at all.Dugong habitats were explicitly taken into consideration when the GBR Marine Park was rezoned in 2003. Approximately 96 per cent of high conservation value dugong habitats are highly protected, and 24 per cent of known shallow water seagrass meadows are included in highly protected green zones which prohibit extractive activities. While it had been recognised for some time that shallow water seagrass meadows in Dugong Protection Areas are at risk from declining water quality, it is now also recognised that deeper water seagrass meadows are also used by dugongs (as a refuge and when preferred shallow water meadows are affected by floods or cyclones). While a trend of decline in shallow inshore seagrass meadows south of Cooktown is recorded, there are major gaps in our understanding of the condition, abundance and distribution of deepwater seagrass meadows. Major efforts to improve water quality through the Reef Water Quality Protection Plan (Reef Plan) are expected to have positive outcomes for seagrass in the medium term.The GBR Marine Park and GBRWHA are jointly managed by the Australian and Queensland governments, as set out in the Great Barrier Reef Intergovernmental Agreement. This Intergovernmental Agreement outlines the obligations of both governments to protect and manage the GBR ecosystem through a joint Field Management Program between the GBRMPA and the Queensland Department of National Parks, Recreation, Sport and Racing through the Queensland Parks and Wildlife Service.The Field Management Program undertakes operations and routine day-to-day activities in the GBR Marine Park, the adjacent GBR Coast Marine Park and island national parks. In addition to compliance management and monitoring, the Field Management Program provides funding for essential facilities, information products, services and permits management activities for high-use sites to prevent harm to the environment and to provide for public use and information.Management of the Region relies upon a number of Australian and Queensland government agencies to regulate access and to control or mitigate impacts associated with activities. These agencies use a combination of management tools.


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1.4.3 Direct protection of dugongs and seagrass

Given their iconic status, dugongs have been a focus of management agencies for many decades. Management to directly protect dugongs and seagrass include GBR Marine Park and Coast Marine Park zoning plans, dugong protection areas and measures to improve water quality.

1.4.3.1 Zoning PlanThe GBR Marine Park Zoning Plan, which came into effect in 2004, governs what activities may be undertaken and where they may be undertaken. The Zoning Plan sets a global benchmark for marine conservation, providing protection from extractive uses for at least 20 per cent of every bioregion, while allowing for a range of ecologically sustainable use and the continuation of traditional activities. Overall, 33 per cent (115 000 square kilometres) of the Region protects coral and coral reef ecosystems in no-take zones including specific scientific research zones and special conservation zones for areas of significant conservation value, where any form of visitation requires a permit. The principal management tools used are the Great Barrier Reef Marine Park Zoning Plan 2003, and the complementary Queensland Marine Parks (Great Barrier Reef Coast) Zoning Plan 2004.Dugong habitats were explicitly taken into consideration when reviewing the zoning of the GBR Marine Park as part of the Representative Areas Program. The biophysical operating principle relating to dugongs was that approximately 50 per cent of all high priority dugong habitat should be included in no-take areas. Other protection measures that came into effect through the Great Barrier Reef Marine Park Zoning Plan 2003 that should benefit dugong habitats including: ▪ Designating the Far Northern Management Area of the GBR

Marine Park as a Remote Nature Area where works involving dumping spoil, reclamation, beach protection works, harbour works and constructing or operating a structure other than a vessel mooring or a navigational aid are prohibited.

▪ Categorising dugongs as Protected Species, which prohibits their direct take without the written permission of the GBRMPA. This led to the development of a reef-wide Policy on managing the direct take of Protected Species from the Marine Park.

▪ Controlling or preventing activities through zoning such as dredging, aquaculture, and other activities which may affect benthic communities such as seagrass.

▪ Special Management Areas (Dugong) were created that have management arrangements the same as for the corresponding Dugong Protection Area found within the Queensland Fisheries Regulations 2008.

▪ Protected species designation.

The area of dugong habitat increased in no-take areas from 1396 square kilometres to 3476 square kilometres (or 16.9 per cent to 42.0 per cent of all identified sites). Although the biophysical operating principles were not achieved in total for all sites, overall the level of protection afforded by the Great Barrier Reef Marine Park Zoning Plan 2003 increased for all locations identified.

1.4.3.2 Dugong Protection AreasThe establishment of Dugong Protection Areas was a critical step in efforts to address the decline of dugong in parts of the GBRWHA and southern Queensland. Zone ‘A’ Dugong Protection Areas include significant dugong habitats in the southern Great Barrier Reef (consistently contain over 50 per cent of dugong numbers). In these areas, the use of offshore set, foreshore set and drift nets are prohibited, except in Hervey Bay and Great Sandy Strait Protection Area where specialised fish netting practises are allowed to continue with modifications. Other netting practices such as ring, seine, tunnel and set pocket netting which are not considered to pose a serious threat to dugong were unaffected.In Zone ‘B’ Dugong Protection Areas mesh netting practices were allowed to continue, but with more rigorous safeguards and restrictions than before. Zone ‘B’ Dugong Protection Areas have been shown to contain about 22 per cent of dugongs in the southern GBR. These measures were reviewed by the Ministerial Council to ensure protection of dugongs in these areas.

1.4.3.3 Improving water qualityPrograms such as Reef Rescue and the Reef Water Quality Protection Plan (Reef Plan) are aimed at improving water quality and are expected to reduce localised stress on inshore reefs and hence enhance their resilience to thermal bleaching and disease, improve the biodiversity of inshore reef habitats, and reduce the long-term risk to the Reef ecosystem from crown-of-thorns starfish.Since 2008, the $200 million Reef Rescue program (as part of Reef Plan) has given more than 2900 land managers funds to improve the quality of water leaving their properties. Trigger values are in place for nine water quality parameters (secchi depth, chlorophyll, suspended solids, particulate, dissolved and total nitrogen, and particulate, dissolved and total phosphorus). If


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exceeded, further management actions need to be put in place to reduce the impacts. The values are derived from over ten years of accumulated data from the Australian Institute of Marine Science. Further information on this can be found in the Water Quality Guidelines for the GBR Marine Park (2010). Early indications are showing that these programs are proving successful in improving water quality.

1.4.4 Management of activities in the

World Heritage Area

1.4.4.1 Commercial net fisheryThe management arrangements for the commercial net fishery are set out in the Queensland Fisheries Act 1994 and Fisheries Regulations 2008. Dugong Protection Areas (DPA’s) were introduced in 1997 reducing mesh netting in areas of high dugong numbers and representing an important step to assisting the recovery of the dugong population south of Cooktown.Dugong Protection Areas were subsequently declared in legislation under the Fisheries Act by the Fisheries Amendment Regulation (No. 11) 1997 (Qld), and as Special Management Areas under the Great Barrier Reef Marine Park Regulations 1983 and the Great Barrier Reef Marine Park Zoning Plan 2003.A review of the effectiveness of the arrangements in 2000 concluded that ‘if the changes to the netting regulations are appropriate and effectively enforced, the introduction of the Zone A Dugong Protection Areas should decrease dugong mortality from commercial gill and mesh nets in the GBR region south of Innisfail by between about 42 per cent and 55 per cent.’ assuming that habitat quality is maintained. Using spatial modelling 57 per cent of dugongs in the GBRWHA are highly protected from incidental drowning in mesh nets and 83 per cent of dugongs occur in areas where trawling is banned. A range of other requirements on net fishers including net attendance rules which were strengthened in 2009. The number of commercial mesh netters licensed to operate in the GBR Region has approximately halved since 1997. The Queensland government has also commenced a $9 million buyout of the East Coast Inshore Fin Fish Fishery which will both improve profitability and have conservation benefits for species including dugong. However, a formal evaluation the effectiveness of changes to netting regulations on dugong mortality rates undertaken in 2000 and again in 2009 has not been undertaken.Continuing to reduce the incidental catch of dugongs in nets is a priority. Commercial fishers from the Burdekin worked with the Authority, Fisheries Queensland, former Department of Environment and Resource Management and the Queensland Seafood Industry Association as part of the Burdekin Regional

Management Project to proactively increase protection to dugong within a critical area of the Bowling Green Bay Species Conservation (Dugong Protection) Special Management Area.Concern in the 1990s over catch of dugongs, dolphins and turtles, in nets set in the Queensland Shark Control Program for bather protection resulted in many nets being replaced with baited hooks known as ‘drumlines’. Nets are now only deployed at ten locations within the GBRWHA, five near Cairns and five near Mackay. This reduced the number of dugongs caught to less than 4.3 dugongs per year between 1992 and 1995. The incidental catch of marine mammals and turtles is recorded, and the release of live animals is a priority. Seventeen per cent of dugongs caught between 1992 and 1995 were released alive, giving an average mortality of about four dugongs per year. Generally one to two dugongs are caught and killed each year in the program.

1.4.4.2 Traditional Use of Marine Resources AgreementsDugongs are of great cultural importance to the Reef’s Traditional Owners. Use of its marine resources, including hunting of dugong, continues in accordance with traditional customary laws and practice. Traditional Owners are supported to maintain their cultural connections with the sea country of the GBR. This is achieved by working in sea country partnerships to develop and implement Traditional Use of Marine Resources Agreements (TUMRAs) and support for cooperative management arrangements. TUMRA’s complement existing community-based measures developed by some Traditional Owner Groups to manage their use of some of these resources and recognised entitlements enshrined in the Native Title Act 1993 (Clth). They promote the sustainable use of threatened (for example, dugongs, turtles) and protected (for example, barramundi cod, giant clams) species within the GBR Marine Park, taking into consideration the other sources of human related mortality that may impact upon these stocks. The intent of these Agreements is to ensure that the use of marine resources is managed sustainably. Some Aboriginal and Torres Strait Islander communities have made voluntary formal and informal decisions not to hunt at all, as a contribution to addressing the decline in dugong numbers in the southern GBR. In addition, unofficial refugia where dugongs are not hunted exist in the GBRWHA. For example, north of Cooktown, weather and the small size of boats used limit the spatial extent of dugong hunting, and travel to hunting grounds is generally limited by road access.


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1.4.5 Managing activities outside the

World Heritage Area

1.4.5.1 Coastal developmentUrban planning in Queensland is managed by the Queensland Government. The Sustainable Planning Act 2009 (SP Act) primarily influences intensive urban and industrial development. The SP Act sets out a number of planning tools, such as local government planning schemes, State Planning Polices and Regional Plans. All State Planning Policies are under review.The GBRMPA’s role in coastal urban planning, decision and management is through influencing decision makers by: ▪ Advice on regional and local planning processes to provide

recognition of the downstream and catchments ecosystem values that require protection

▪ Coastal development assessment role ▪ Consultation engagement of the community, industry and

government through advisory groups and stewardship programs.

At the local scale, Local Government employs area plans to indicate appropriate development areas, while reflecting broader resource protection areas. Local Government plans are due for review. Broader interests in Local Government planning are provided by the Queensland Government, and include areas of ecological significance, good agricultural land, resource development areas, waterway management and fish habitat areas. Many of the interests may also be captured in Queensland Government regional planning which provides a broad guide on priority areas for future development, application of protected area policy and identification of important regional sites and localities. The intent of the regional plans is to guide development decisions, development assessment and local government planning.

1.4.5.2 PortsThe planning and development responsibilities for ports lies with the Queensland Government and the Department of the Environment. For a detailed assessment of the management of ports by the Queensland Government, please refer to the demonstration case on Abbot Point in the GBR coastal zone Strategic Assessment.

New project proposals are currently being assessed that potentially involve dredging in the GBRWHA. The assessment process will consider the extent of dredging required, the amount of dredge spoil, and the management of these activities to make a determination about whether the impacts are sufficiently mitigated. If approved, a set of conditions will be established to monitor dredging activity in order to protect and minimise those impacts to the GBRWHA. The cumulative impacts of multiple projects on the GBRWHA will be taken into account in this process as will be the staging of development of each project. Historically, the number of project proposals that do not get approved far outnumber those that do obtain approval.

1.4.6 Offsetting impacts on dugong

Queensland currently has an overarching Queensland Government Environmental Offset Policy which provides the principles for offsets in Queensland and forms the foundation for development of detailed specific-issue offset policies.The Environmental Offset Policy offset principles are as follows:Principle 1: Offsets will not replace or undermine existing environmental standards or regulatory requirements, or be used to allow development in areas otherwise prohibited through legislation or policy.Principle 2: Environmental impacts must first be avoided, then minimised, before considering the use of offsets for any remaining impact.Principle 3: Offsets must achieve an equivalent or better environmental outcome.Principle 4: Offsets must provide environmental values as similar as possible to those being lost.Principle 5: Offset provision should minimise the time-lag between the impact and delivery of the offset.Principle 6: Offsets must provide additional protection to environmental values at risk, or additional management actions to improve environmental values.Principle 7: Offsets must be legally secured for the duration of the offset requirement.Four specific issue policies currently support the Environmental Offset Policy: ▪ Marine Fish Habitat Offsets Policy ▪ Offsets for a Net Gain in Bushland Koala Habitat in South

East Queensland Policy ▪ Policy for Vegetation Management Offsets ▪ Queensland Biodiversity Offsets Policy.


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The Marine Fish Habitat Offsets Policy is the only specific issue offsets policy that is applicable to this demonstration case.Environmental offsets have been required for marine habitats of the Great Barrier Reef under Queensland’s Marine Fish Habitat Offset Policy since 2002, the first offset policy for the marine environment in Australia. The Marine Fish Habitat Offsets Policy protects marine plants as defined by the Fisheries Act:(1) Marine plant includes the following ▪ a plant (a tidal plant) that usually grows on, or adjacent to,

tidal land, whether it is living, dead, standing or fallen ▪ material of a tidal plant, or other plant material on tidal land ▪ a plant, or material of a plant, prescribed under a regulation

or management plan to be a marine plant.(2) Marine plant does not include a plant that is a declared pest under the Land Protection (Pest and Stock Route Management) Act 2002.

1.5 Measures to enhance MNES

The Reef Water Quality Protection Plan (Reef Plan) is a collaborative program of coordinated projects and partnerships designed to improve the quality of water in the GBR though improved land management in reef catchments. The goals of the Plan are to halt and reverse the decline in water quality entering the reef by 2013, and to ensure that by 2020 the quality of water entering the reef from adjacent catchments has no detrimental impact on the health and resilience of the GBR. Reef Plan sets ambitious but achievable targets for water quality and land management improvement, and identifies actions to improve the quality of water entering the GBR. Achieving these targets will assist in reversing the decline in seagrass condition, and the capacity for dugong populations to recover in the GBR.The plan is a joint Australian and Queensland Government initiative that specifically focuses on diffuse source pollution from broad scale agriculture. This is where irrigation or rainfall carries pollutants such as sediments, nutrients and pesticides from agricultural land into waterways and the reef lagoon. Initially established in 2003, the plan was updated in 2009. It details specific actions and deliverables and is currently being reviewed.

1.6 Information gaps and how they are being addressed

There has been a significant body of research and monitoring funded by Australian and Queensland governments to address information gaps so that management is informed by and based on the best available science. The Dugong Research Strategy 2006-2011, and the GBRMPA’s Scientific Research Information Needs establish research priorities for dugong and management respectively. There are other information gaps limiting our understanding of interactions with dugongs directly, including: ▪ Reporting on interaction in the East Coast Inshore Fin Fish

Fishery. Unfortunately, as of 2012 Queensland’s Fisheries Observer Program is no longer operational. The program was an important process to independently determine the level of dugong bycatch in this commercial fishery. This may affect performance monitoring of the fishery pursuant to Wildlife Trade Organisation obligations in future, and will affect the GBRMPA’s understanding of the ecological risk to dugong from this fishery. Underestimates of interactions reported by fishers themselves in their Species of Conservation Interest logbooks, administered by Fisheries Queensland, are known to significantly underestimate levels of interaction in other species.

▪ An understanding of the current and potential level of hunting of dugongs by Traditional Owners, particularly in the northern GBRWHA. There are significant opportunities to improve knowledge on fishing gear technology that reduce incidental capture of dugong and these are highlighted below.

Other information gaps are limiting our understanding of seagrass declines, including: ▪ Monitoring and reporting of point source discharge of

pollutants into the GBRWHA. ▪ The response of seagrasses to cumulative impacts to

determine the water-quality conditions that lead to these changes, and the acceptable levels of change in seagrass meadows in response to such factors. Some of these information gaps are being progressively filled by research scientists, and are reported through scientific consensus statements prepared to support the Reef Plan.

▪ Impacts of noise pollution and mitigation strategies. Management strategies employed in Europe includes surrounding underwater construction sites with ‘bubble curtains’ to contain much of the underwater noise, and a gradual ramping up of pile-driving activity which gives animals the opportunity to leave the area.


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1.6.1 Reducing incidental capture in nets

Understanding how, when and why interactions between dugongs and fishing nets occur is critical to address the risk of entanglement. It is important to understand how dugongs how perceive and respond to fishing nets, and how movement patterns and behaviours may of dugongs vulnerable to capture. In the meantime, research is addressing how technology and near gear designs may reduce the risks of incidental capture.Since 1991, the Queensland Government has conducted research on the effectiveness of acoustic alarms or ‘pingers’ to alert marine mammals such as dugongs to the presence of nets. These alarms have been successful in reducing the incidental capture of some species of cetaceans in mesh nets in other countries.Unfortunately, experiments testing the effects of acoustic alarms on dugong behaviour indicate that 10 kHz ‘pingers’ do not cause a startle response; do not cause dugongs to move away from the immediate area; do not elicit an investigative response, and are unlikely to displace dugongs from key habitat areas or reduce dugong mortalities in fishing nets. In a trial of 4 and 16 kHz ‘pingers’ which were fitted to fisheries nets to reduce incidental catches, no behavioural responses were detected.Large non-target animals can become entangled in the standard gillnets currently used in northern Australia’s inshore commercial fisheries allow, causing drowning, harm or death to the animal as it tries to free itself. This requires the fisher attempt to to interact with the animal to try to cut it free, creating an unnecessary hazard to the fisher and the vessel. This also reduces the efficiency and profitability of the fishing gear.A project has commenced to identify and test net designs that decrease the likelihood of species of conservation concern getting caught, while improving safety and maintaining the fishing efficiency for target species such as barramundi. The modified net functions by having ‘collapsible’ panels that allows very large animals to push through rather than becoming entangled. The panels are readily re-tied therefore minimising any impact on fishing efficiency.This design was tested during preliminary trials in Moreton Bay during 2007/08 and 2009/10 in research conducted by the Moreton Bay Seafood Industry Association. Results showed no change in target species catch rates, while showing promise in reducing interactions with Species of Conservation Interest and other large non-target species such as large shovelnose rays. This provided evidence of ‘proof of concept’ however was based on limited interactions. A more comprehensive test of the design is therefore required before decisions can be made about promoting the design for use in inshore net fisheries. These tests are scheduled for further trial in Moreton Bay and also the more turbid waters of Bowling Green Bay.

1.6.2 Integration of monitoring and evaluation

Within the Region, monitoring is carried out by a wide range of research providers such as the Australian Institute of Marine Science, CSIRO, government agencies (such as the GBRMPA and the Queensland Department of Agriculture, Fisheries and Forestry) and universities, as well as by commercial companies, consultants, stakeholders and community members. Existing monitoring programs have largely been designed to address and report on a specific issue, location or management initiative. A review of these monitoring programs has identified that most key management needs are currently being addressed by some form of monitoring, but in many cases it is too limited, either spatially or temporally, to adequately meet information needs. Additionally, there is a lack of indicators which address the full suite of biophysical and socio-economic values and a need for improved data standardisation, discoverability and accessibility.

1.7 Program effectiveness

The most critical ongoing management action for Queensland toward the protection of dugongs is to ensure the health of seagrass meadows. Fundamental to the recovery of dugong populations, is improving water quality of the GBR lagoon and thereby the condition of seagrass habitat that dugong are dependent upon. Despite the impact of human activity, the occurrence of unforeseen extreme weather events presents a significant risk to the stability of seagrass habitats and the subsequent dugong population.Reversing the decline in water quality entering the GBR lagoon and minimising disturbances from direct use are the key strategies in the Queensland Government’s approach to promoting the resilience of the species through habitat protection. The dugong population varies between the northern and southern areas of the GBR. Based on what is understood about the incidence of dugongs, the northern area of the GBR has sufficient resilience to enable a more stable dugong population after extreme weather events unlike the southern area which shows signs of decline and a diminished resilience for the dugong population resulting in heightened vulnerability to extreme weather events. It is thought that the diminished resilience in the southern area of the GBR has been the result of vessel strikes, flooding and subsequent water quality issues, and other human activities all of which has contributed to reducing habitat condition resulting in habitat degradation and loss during extreme weather events. Consequently the Program is designed to respond to these events through the establishment of responses to these conditions through programs to improve water quality and build habitat resilience in the GBR.


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Significant mortality occurs after a severe weather event, and even low levels of human-induced mortality may hinder the ability of dugong populations to recover in these circumstances. Compared to other GBRWHA wildlife, monitoring and understanding are good, there are some fundamental limitations with:(i) aerial surveys can be inaccurate(ii) it is unknown if dugongs migrate in response to seagrass loss(iii) population structure remains uncertain in the GBR(iv) there is limited data on Traditional Owner hunting.

1.7.1 Projected condition

Drivers, activities and impacts form a complex web of interactions which affect dugongs and seagrass. Qualitative models within a Bayesian network have been used to understand the projected condition of dugongs and other key interacting species in seagrass ecosystems. The output describes the response of the species (increase, unchanged or decrease), based on a series of future scenarios for selected impacts.For example, structural damage and erosion and ocean warming are predicted to occur under climate change scenarios. A conservative 50 per cent chance of an increase in these impacts was modelled. Under this scenario the predicted response of most variables, including dugongs, was highly ambiguous, with a 40 per cent probability of decline, and about a 60 per cent chance for increase or no change.

Next, scenario three examined the cumulative effects of the previous climate change scenarios, together with improvements to water quality based on achieving the Reef Plan targets. The scenario modelled an 80 per cent likelihood of a significant decrease in nutrients and 50 per cent likelihood of a significant decrease in turbidity and suspended sediments. Here dugongs have a slightly greater likelihood for both increase and decrease, and the distribution of their likelihood for change mirrors that of seagrass abundance. Finally, the consequence of a reduction in mortality of dugongs to the above climate change and water quality scenario was assessed. The outcome for this scenario was a greater chance for increase in dugongs.In conclusion, model outputs based on a possible increase in storms and ocean warming predict a likely downward trend in dugong populations, even with a possible reduction in nutrients and sediments (based on Reef Plan targets), unless direct human-induced dugong mortality is decreased concurrently.

Measure Effectiveness Confidence Trend Comments

Demonstrated ability to identify MNES including OUV

Effective There is a good understanding of the most critical habitat locations. Environmental impact statement (EIS) processes for significant projects are effective at identifying dugongs and the environmental values that support them. Aerial surveys provide an indicative understanding of dugong population trends

Demonstrated ability to assess impacts

Effective There is a good understanding of a broad range of impacts on dugong. The most significant impacts are from impacts on seagrass stemming from extreme weather and catchment run-off.Anthropogenic sources of mortality are monitored in the Queensland Marine Wildlife Strandings and Mortality Program.


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Effectiveness in avoiding impacts

Partially effective Approximately 96 per cent of high conservation value dugong habitats are protected as a combined result of the state and Commonwealth zoning network and other management arrangements (for example, improving water quality and fisheries management arrangements).The northern area of the GBR has sufficient seagrass habitat resilience to enable a more stable dugong population after extreme weather events. The southern area of the GBR shows a decline in seagrass habit thought to be caused by flooding and subsequent water quality issues and human activities resulting in habitat degradation and loss during extreme weather events.The impact of extreme weather events is difficult to overcome and beyond the scope of the Program.Despite the extent of protection for dugong habitats, the time lag between investing in water quality improvement programs and positive outcomes for waters of the Reef lagoon is great.Progress is being made towards the initial objective of reversing the decline in the quality of water entering the Reef lagoon as noted in the recently released Great Barrier Reef Second Report Card 2010. Sustained improvement in catchment management practices is required over the long term to bring catchment water quality to meet Water Quality Guidelines.

Effectiveness in mitigating impacts

Partially effective Where impacts on dugongs are able to be mitigated, steps are being taken to mitigate those impacts. A move towards baited drumlines in the shark control program has minimised incidental capture. Net attendance rules for commercial fishers ensure incidentally caught dugongs can be released more successfully.Ongoing programs to improve water quality help improve the condition of habitat that dugong rely upon. Improved habitat increases the resilience of the dugong population to recover from anthropogenic and nature weather events. A key target of the Reef Plan is to achieve a 50 per cent reduction in nutrient loads entering the Great Barrier Reef by 2013. Total fertiliser use on farming lands in the catchment has been reduced in recent years. Recent monitoring show current initiatives are successfully reducing nutrient concentrations in catchment run-off.


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Effectiveness in offsetting unavoidable impacts

Partially effective A Marine Fish Habitat Offsets Policy has been in place since 2002 to ensure that projects that have unavoidable impacts on seagrass provide offsets for those impacts.Limitations in the physical ability to create new seagrass offsets means that it is very difficult to implement ‘like for like’ offsets for seagrass. The Queensland Government is reviewing offsetting programs to ensure that offset policies deliver the best environmental outcomes possible.

Contribution to enhancement of MNES including OUV and management of existing pressures

Effective Efforts to improve water quality through the Reef Plan will provide significant benefits for seagrasses and dugongs in turn.

Demonstrated ability to adapt the system over time to incorporate new knowledge

Effective As new information becomes available, mechanisms can adapt to accommodate for flexibility in the system. This has been demonstrated by the introduction of baited drumlines in the shark control program in response to the incidental capture events and the instruction of rules for commercial fishers to enable incidentally caught dugongs to be released more successfully.

Overall effectiveness

Partially effective Overall, management is partially effective at minimising impacts. Even low levels of incidental capture or impacts on seagrass has a significant impact on the ability for dugong to recover from severe weather events.


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1.7.1.1 Projection north of CooktownThe current dugong population in the northern GBR and Torres Strait is substantial (>20 000 individuals). A 20-year time-series of aerial surveys of the remote GBR coast has not detected a significant decline in dugong numbers, although this scenario cannot be ruled out. Climate change is expected to impact on the extent, abundance and condition of seagrass meadows, although sea temperature increases may be positive in the shortterm.Catchment run-off will continue to have some impacts as a result of broadscale agriculture in Cape York. Development of broad scale or intensive agriculture is projected to escalate, and loss of seagrass habitat is likely to occur with decreased water quality. Development pressures and fishing effort north of Cooktown are significantly lower than the southern GBR but are expected to increase in future.

1.7.1.2 Projection south of CooktownThe conservation status for dugongs in the area is cause for extreme concern, given their limited population recovery potential, the impact of extreme weather events on seagrass and the need to substantially reduce humaninduced annual mortality to recover the population.As a direct driver, climate change is expected to impact on the extent, abundance and condition of seagrass meadows. Sea temperature increases may be positive in the short-term, but more extreme weather may have negative impacts.The increased shipping, urban and port development and recreation are expected to increase the level of impacts which dugongs are currently exposed to from vessel strike and marine debris, although some impacts may be localised. Catchment run-off is expected to continue to impact on seagrass in the short term given the long timelag in seeing improved land management practices translate into improved marine ecosystem health. The time-lags may be shorter for pesticides compared to sediment, which could take decades to reverse.Fishing activities involving set mesh nets occur widely along the coast and there is a moderate degree of latent effort associated with the current management arrangements for the fishery. A $9 million buyout of the fishery is expected to reduce the risk of effort increasing in the fishery and also provide conservation benefits directly to dugong by reducing the risk of incidental capture.

1.7.2 Potential improvements

In this regard, the most critical ongoing Program management action for dugongs is to ensure that the health of seagrass meadows on which they rely for food is maintained, enhanced and restored. The recovery, protection and increased resilience of seagrass habitats are fundamental to the recovery of dugong populations.In the GBRWHA to the north of Cooktown, it will be critical to protect seagrass habitat from activities that will reduce the quality of water entering the GBRWHA or that have direct impacts on seagrass meadows. In the GBRWHA south of Cooktown where dugongs are most vulnerable, the most critical actions are to recover, protect and build the resilience of seagrass habitat. It will be particularly important to protect remaining seagrass meadows and work towards improving conditions for seagrass recovery, including reversing the decline in water quality entering the GBR lagoon and minimising disturbances from direct use, especially relating to coastal development.It is also critical that direct anthropogenic impacts on dugongs (for example from hunting, poaching, net entanglement, vessel strike and marine debris) are reduced. Strengthening a number of ongoing management actions is important and it will be imperative for the wider community to have a more prominent role in the formulation and implementation of management arrangements to recover dugong populations across the GBRWHA. Continuously improving net fishing techniques and technology is important to reduce entanglement and drowning in fishing nets. Community action and compliance activities at a local and regional scale are still needed to help reduce and minimise mortality or ill-health of dugongs (for example, vessel strike, marine debris, disease, noise and interference).TUMRA will continue to act as a valuable tool to facilitate sustainable traditional hunting, and provide for the exchange and incorporation of traditional ecological knowledge of species so that management is based on the best available information.Adaptive management requires an ongoing commitment to regular monitoring, evaluation and review of the abundance and distribution of dugongs and seagrass to allow a better understanding of trends. A greater understanding of cumulative impacts, including impacts of extreme weather on dugongs and seagrass must lead to an improvement in the adequacy of measures to avoid or mitigate impacts in important dugong areas. This could even include investigating ways of restoring and rehabilitating seagrass meadows.


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In addition, supporting the objectives of the Queensland Government’s current net buyback program to reduce effort in the East Coast Inshore Fin Fish Fishery is important, given that concerns remain about set mesh netting, and the potential for the mortality of vulnerable species in nets and some failures to report these interactions in the Lockhart River and Princess Charlotte Bay areas. Potential new initiatives outside the jurisdiction of the Authority could include a further revision of apparatus used in the Queensland Shark Control.

Documents

BRISBANE GOLD COAST - Department of State … COAST STRA SESSMENT 8-4 8 - The total area within the GBRWHA predicted to be of conservation value for dugong were 2399 square kilometres