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Excerpt from |
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DUGONG |
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Status Report and Action Plans for Countries and Territories |
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| Download full version (.pdf document (1,857kb)) | ||
| Compiled by | ||
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HELENE MARSH |
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Action Plan Coordinator IUCN/SSC Sirenia Specialist Group |
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HELEN PENROSE,CAROLE EROS, AND JOANNA HUGUES |
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School of Tropical Environment Studies and Geography James Cook University, Townsville, Australia Cooperative Research Centre for the Great Barrier Reef World Heritage Area James Cook University, Townsville, Australia United Nations Environment Programme World Conservation Monitoring Centre Cambridge, United Kingdom |
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URBAN COAST OF QUEENSLAND |
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For the purposes of this document, the "urban" coast of Queensland (Figure 6.6) is defined as extending from
Cooktown to the border of Queensland and New South Wales at Coolangatta. The area from Cape Bedford near
Cooktown to the southern boundary of the Great Barrier Reef Marine Park (Figure 6.6), is within the Great
Barrier Reef World Heritage Area, and is jointly managed by the Great Barrier Reef Marine Park Authority
(GBRMPA) and the Queensland Parks and Wildlife Service (QPWS). South of this region, dugong management is
the responsibility of the Queensland Parks and Wildlife Service. |
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| Distribution and Abundance | ||
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Relative to the northern Great Barrier Reef and Torres Strait (see above), dugongs are generally sparsely distributed
throughout the southern Great Barrier Reef region. This is not surprising considering the small known area of inshore
seagrass (approx. 540km2, Lee Long & Coles 1997), compared to the region north of Cape Bedford (2252km2, Lee Long et al.
1993) and the relatively small size of individual meadows. Five seagrasses from the genus Halophila have been found at
depths down to 60m between 10° to 25°S and from inshore to the reef edge (up to 120 nautical miles from the coast). These
deepwater meadows (>15m) of H. ovalis and H. spinulosa are important feeding habitat for dugongs. Cross-shelf patterns in
seagrass presence, species and biomass are likely to be linked with coastal influences (Coles et al. 2000). The most important dugong areas along the urban coast (Hinchinbrook Island area, Cleveland Bay and Shoalwater Bay in the Great Barrier Reef region, and Hervey Bay and Moreton Bay to the south; Figure 6.6) are typically large, northward facing bays, which are sheltered from the prevailing southeast winds. These bays support much of the large areas of seagrass on this coast. Our capacity to interpret the long-term trends in dugong abundance along the urban coast of Queensland is complicated by increasing evidence of the dugongs' large-scale movements. Overall, the available evidence suggests a long-term decline at a regional scale, with shorter-term fluctuations in dugong numbers at more local scales. The evidence for a long-term decline comes from anecdotal information and records of dugong by-catch from a government shark control program. Marsh et al. (2001) used these records to hindcast changes in dugong numbers over the last four decades along a 100 latitude between Cairns and the Sunshine Coast (Figure 6.6). The results from six locations indicate that the overall capture rate declined at an average of 8.7% per year. The estimated decline in shark net by-catch of dugongs was used to estimate the decline in dugong numbers from all causes averaged over the areas where nets were deployed. This hindcasting suggests that dugong numbers have declined to about 3% of the 1960s level. This hindcasting makes the untested assumptions that dugongs have not learned to avoid the nets, or been alienated from beaches where nets have been deployed due to increased human use. The causes of this decline are complex and probably vary in different areas along the coast (see below). A series of standardised aerial surveys between 1986/87 and 1994 suggested a decline in dugong numbers in the Great Barrier Reef World Heritage Area between Hinchinbrook Island and the southern boundary of the region (Figure 6.6). The number of dugongs in the region changed from an estimated 3,479 (± s.e. 459) in 1986/87 to 1,857 (± s.e. 292) in 1992 and 1,682 (± s.e. 236) in 1994 (Marsh et al. 1996). The population estimate derived from the 1994 surveys was only 48% of the 1986/1987 population estimate. Comparison of the results of the 1986/7, 1992 and 1994 surveys indicated that the decline in dugong numbers was spread throughout much of the region, but was most serious between Cape Cleveland and Broad Sound (Figure 6.6). Another standardised aerial survey in the time series was conducted in 1999 (Marsh & Lawler 2001a). The results of this survey indicate that dugong numbers in the southern Great Barrier Reef region in October-December 1999 were significantly higher than the corresponding estimate in 1994, but not significantly different from that obtained in 1986/87. Most of the increase was in the northern part of the survey region between the Whitsunday and Hinchinbrook areas (Figure 6.6). An aerial survey of the Hervey Bay-Great Sandy Strait region in 1988 indicated that this area supported the largest population of dugongs (estimated at 2,206 ± s.e. 420) and the largest area of seagrass (>1000km2) (Lee Long et al. 1993) on the east coast of Australia south of Cape York. The seagrass was predominantly in water deeper than 5m, and in the southwest of Hervey Bay. The survey was repeated in 1992. It revealed a large decrease in dugong numbers in southern Hervey Bay per se from 1,753 (± s.e. 388) in August 1988 to approximately 71 (± s.e. 40) in 1992. Most of the animals appear to have travelled south to Great Sandy Strait where the population was estimated to be 943 (± s.e. 377) in 1992 (Preen & Marsh 1995). By December 1993, the dugong population |
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Figure 6.6 - The urbanised coast of Queensland (from Cooktown south on this map) showing place names mentioned in the text and the Dugong Protection Areas. Inset bottom left: Moreton Bay region, southeast Queensland. |
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of the Hervey Bay-Great Sandy Strait region was estimated to be 579-629 (± s.e. 126) animals (Figure 6.6). Based on
a survey in November 1994, a minimum population estimate of 807 (± s.e. 151) dugongs was calculated for the
region (Marsh et al. 1996). When this survey was repeated in November 1999, dugong numbers were estimated to
be 1654 (± s.e. 248) (Marsh & Lawler 2001a). The April 2001 aerial survey estimate was 919 (± s.e. 146) dugongs,
including 8.5% calves (Lawler 2001b). The increase in dugong population estimates for the Southern Great Barrier
Reef region and Hervey Bay between 1994 and 1999, were too great to be attributed simply to natural increase in
the absence of migration (Marsh & Lawler 2001a). Satellite tracking of individual dugongs provides evidence of
such migrations. For example one dugong travelled from Hinchinbrook Island to Princess Charlotte Bay and back,
and then to Cleveland Bay (near Townsville), a distance of about 800km, while two others moved from Shoalwater
Bay to Hervey Bay (Preen 1999, 2001). Of the 29 animals that were tracked, over half moved linear distances of
greater than 70km (Lawler pers comm. 2001). Although there are many historical accounts of Moreton Bay as an important dugong area (e.g. Welsby 1905), dugongs were not recorded there by scientists from the air until the mid 1970s. The animals were sighted on the sandbanks to the west of South Passage (Heinsohn et al. 1978). Only one quantitative survey of the entire Bay was conducted prior to 1995 (in August 1988). This survey resulted in a population estimate of 458 (± s.e. 78) dugongs, most of which were found in the South Passage and associated banks (Marsh et al. 1990). Between July 1988 and February 1990, Preen (1992) conducted 28 standardised surveys of the South Passage area and concluded that it supported between 500 and 569 dugongs all year round. Following a repeat survey in April 1993, Preen and Marsh (1995) estimated a population of about 650 dugongs in the same area. In 1995, Lanyon and Morrice (1997) counted dugongs during six repeat bimonthly aerial surveys. Population estimates ranged from 366 (± s.e. 159) in July, to 896 (± s.e. 201) in January, with a mean population estimate of 658 (± s.e. 87) over the entire survey period. Lawler (2001a) estimated the dugong population of Moreton Bay to be 344 (± s.e. 88) in December 2000. In April 2001, the population estimate was 366 (± s.e. 41) individuals, including 10.7% calves (Lawler 2001b). The methodology of all these surveys has not been consistent, so comparisons between the various population estimates are problematic. However, all surveys concluded that the eastern Amity and Moreton Banks, and the areas adjacent to these sandbanks, are the most critical areas for dugongs in Moreton Bay (Figure 6.6). The waters through Rous Channel and east of South Passage (up to 10m offshore from Moreton Island) are frequently used in cooler months (Preen 1992; Lanyon & Morrice 1997). Satellite tracking of individual dugongs confirmed that they leave Moreton Bay on an almost daily basis in winter to seek thermal refuge in the warm oceanic water outside South Passage (Preen 1992). |
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| Threatening Processes | ||
| Habitat Loss and Degradation | ||
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Anthropogenic influences on seagrass beds range from being minimal in areas in the north of the urban coast of
Queensland such as Cooktown, to high in industrial and residential areas around cities such as Cairns,
Townsville, Mackay, Gladstone and especially Brisbane (Figure 6.6). Southeast Queensland is one of the
fastest areas for human population growth in Australia. The most immediate threats to seagrass beds are from urban and agricultural runoff, and coastal developments. Cattle grazing and sugar cane farming in the catchments that feed into the coastal waters of this region may have detrimental effects on seagrass through increasing turbidity, altering levels of nutrient loading and the introduction of herbicides. Localities that provide shelter and water conditions ideal for productive seagrass habitat, are often sites for port development and/or are at the downstream end of heavily disturbed catchments. Following two floods and a cyclone in early 1992, more than 1000km2 of seagrass were lost from Hervey Bay (Preen et al. 1995). Between March 1992 and May 1993, a total of 99 dugong carcasses were recovered in the Hervey Bay area, on the southern and central Queensland coast and along the New South Wales coast, most appeared to have been suffering from starvation. This is likely to be a substantial underestimate of dugong mortality during this period (Preen & Marsh 1995). A seagrass survey in early 1993 confirmed that virtually all the seagrass from southwestern Hervey Bay had disappeared (Preen et al. 1993). Some recovery of the seagrass beds in Hervey Bay was reported by Preen et al. 1995. Coles (pers comm. 1999) reported an almost complete recovery by late 1998. Hervey Bay again experienced significant flooding in February 1999, with substantial loss of inter-tidal seagrasses in the northern Great Sandy Straits, and of shallow sub-tidal seagrasses in the Bay itself (McKenzie et al. 2000). At the time of the 1999 aerial survey, the shallow water seagrasses showed little evidence of recovery (McKenzie et al. 2000), and this is reflected in a change in the dugong distribution in Hervey Bay with more sightings in deeper water than recorded in 1994. McKenzie et al. (2000) suggest that sufficient seagrasses remain to support the current dugong population, but that some individuals may experience stress due to reduced food availability. The future of dugongs in Hervey Bay probably depends on both the intensity and frequency of major cyclone and flood events in the catchments feeding in to the Bay and on the management of land-use in these catchments. Over 60% of Queensland's population lives within 160km of Brisbane (Figure 6.6). The Moreton Bay catchment supports approximately two million people and is the most populated catchment in Queensland (EPA 2001). Much of the effluent from this population centre, the discharges from local industries and the runoff from gardens, roads and surrounding farms, ends up in the Bay. Furthermore, Moreton Bay is a focus area for recreational activities in southeast Queensland. Maintaining the habitat quality of dugongs in Moreton Bay in the face of this increasing pressure will be the major challenge for dugong conservation in this region. The most extensive seagrass beds occur in the sandbanks of eastern Moreton Bay. Over a five year period, decreases in seagrass depth range (the maximum depth of seagrass growth) were recorded in western Bay areas, which are affected by river plumes (Abal et al. 1998). Seagrass loss has also been documented near the mouth of the Logan River, a turbid river with increased land use in its watershed ( Abal & Dennison 1996) (Figure 6.6). Abal et al. (1998) report that the ongoing loss of seagrass in southern Moreton Bay and the inferred seagrass losses in Bramble and Deception Bays, have resulted in an estimated 20% loss of seagrass habitats since European settlement (Figure 6.6). Lyngbya majuscula, a cyanobacterium, is considered to be the biggest challenge to the ecological health of seagrass beds on Moreton Bay. Lyngbya blooms smother seagrass, particularly Zostera marina. Intermittent Lyngbya blooms have been reported from Deception Bay for several years. In 2000, these blooms extended over 38km2 in eastern and northern Moreton Bay (Haines & Limpus 2000), including favoured dugong habitats. This bloom was followed by the largest number of dugong deaths (20) recorded in the Bay for the six years of comprehensive monitoring (Haines & Limpus 2000). The Annual Report Card of Ecosystem Health of the major waterways in Southeast Queensland is derived each year using a range of water quality and biological indicators including the extent and duration of Lyngbya blooms. In 2001, significant Lyngbya blooms occurred in Northern Deception Bay and on the Eastern Banks of Moreton Bay during summer. These banks include Amity and Moreton Banks (see Figure 6.6). The Lyngbya blooms on the Eastern Banks persisted into winter (Holland pers comm. 2001). The extent and duration of blooms in this area may have serious impacts on the seagrass and consequently dugongs (Holland pers comm. 2001; Lemm pers comm. 2001). On the basis of this finding, the 2001 Annual Report Card of Ecosystem Health has downgraded the health of the Eastern Banks from good to fair within a year. This is a dramatic decrease which illustrates the serious nature of this issue (Holland pers comm. 2001; Lemm pers comm. 2001). The impact of extreme weather events on the dugong's seagrass habitat seems to be influenced by land-use. For example, anecdotal evidence suggests that the loss of seagrass from Hervey Bay following the 1992 floods and cyclone was unprecedented in the past 100 years, even though the magnitude of the flood was not (Preen et al. 1995). Preen et al. concluded that the impacts of natural disturbance on seagrass beds can be exacerbated by poor catchment management. Catchment activities including vegetation clearing, grazing, agriculture, aquaculture and urban and industrial development may result in increased sediments and nutrients entering coastal waters. In the central Great Barrier Reef World Heritage Area for example, 39% of all nitrogen and 52% of phosphorous originate from river inputs (Cosser 1997). The increase in sediment and nutrient load from these activities may affect the ability of seagrass beds to recover from damage caused by natural events (Wachenfeld et al. 1998). The amount of sediments, nitrogen and phosphorous entering Queensland's oceans each year has increased three to fivefold since European settlement (~1850), with most originating from large areas of agricultural land in central and northern Queensland (Moss et al. 1993). Probably the greatest threat to seagrass habitat is land runoff and its effect on water quality (Wachenfeld et al. 1998). Herbicide runoff from agricultural lands also presents a potential risk to seagrass functioning adjacent to sugarcane production areas (Haynes et al. 2000 a and b). Unfortunately data are not available to indicate the extent of change in seagrass habitats off the east coast of Queensland, over a significant time-frame. However, it is likely that the changes in water quality have reduced the depth range of at least some species of sub-tidal seagrasses in the region (Abal & Dennison 1996). |
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| Fishing Pressure | ||
| Mesh Netting | ||
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The anecdotal information available in 1997 suggested that by-catch of dugongs in commercial mesh nets was a
significant source of anthropogenic mortality for dugongs in the southern Great Barrier Reef region and Hervey
Bay. Anecdotal evidence also suggests that unlicensed mesh netting is relatively common, and is increasing in northern
Queensland waters despite its illegality (see The Queensland Fisherman July 1999). There are no data on these nets as
a source of dugong mortality, but we regard some mortality as inevitable. A series of Dugong Protection Areas in which
gill and mesh net fishing has been modified or banned was established in 1997 (see below and Marsh 2000). Statistics
from a necropsy program conducted since the introduction of the Dugong Protection Areas indicate that few of the
animals necropsied show evidence of having been killed in nets. For example, in 2000 no dugong mortality from
netting activity was identified in the Dugong Protection Areas (Haines & Limpus 2000). However, two dead dugongs
recovered from the Cairns-Port Douglas area were entangled in monofilament nylon net (Haines & Limpus 2000). The Yarrabah Aboriginal Community near Cairns operates a mesh net fishery in the bay adjacent to the community to supply community food needs. There are anecdotal reports (but no quantitative data) of multiple dugong captures in this fishery in 2000. One animal was released alive from a net (Haines & Limpus 2000). |
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| The Queensland Shark Control Program (QSCP) | ||
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The Queensland Shark Control Program is designed to protect bathers by reducing shark populations on meshed beaches.
The program resulted in a by-catch of a total of 837 dugongs between 1962 and 1992 Anon. (1992), an average of about
27 per year. Between 1962 and 1978, 101 dugongs were killed in nets off Cairns (Paterson 1979), an area where there
are now so few dugongs that the population cannot be estimated (Marsh & Saalfeld 1989; Marsh et al. 1994b; Marsh &
Lawler unpublished). Between 1963 and 1978, 229 dugongs were killed in nets off Townsville (Paterson 1979). As outlined below, a series of initiatives since 1992 have reduced the capture of non-target species in the Queensland Shark Control Program, and the number of dugongs now taken is relatively low (approximately 2 per year; see Haines & Limpus 2000). |
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| Indigenous Use and Hunting | ||
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The contemporary cultural significance of the dugong to urban Aboriginal and Torres Strait Islander peoples in
Queensland has not been studied formally, however there are strong indications that it is considerable and widespread.
Some 27,509 indigenous males reside along the urban coast (i.e. within census collection districts whose centre point
is within 20km of the coast) (Australian Bureau of Statistics 1996). This is almost ten times the number in the
northern Great Barrier Reef and Torres Strait. It is unknown however, how many of these men living on the urban
coast aspire to hunt dugongs. Many are Torres Strait Islanders who are accustomed to having dugong in their diet
(Johannes & MacFarlane 1991; Harris et al. 1994). There are few historical data on the magnitude of indigenous hunting along the urban coast of Queensland. As a response to declining numbers of dugongs in the southern Great Barrier Reef region, the managing agencies no longer issue permits for hunting dugongs in that region. Some indigenous communities agree with this action, while others object to it. There is an established tradition of bartering and trading dugong meat along this coast. The selling of dugong meat by indigenous and non-indigenous people also occurs throughout this region even though it is illegal. Current State and Commonwealth Marine Parks legislation identifies traditional hunting as an activity that requires a permit. However, under State waters, this provision must now be considered in conjunction with Section 211 of the Native Title Act 1993 and Queensland Parks and Wildlife Policy to determine whether a permit is required. The situation is complex and as yet unresolved. There are several indigenous communities in the Hervey Bay region. Although no formal agreement exists, a voluntary cessation of traditional hunting for dugongs is currently in effect. Although not extensive, indigenous dugong hunting does occur. In the past three years, four or five dugongs were hunted 'illegally' (Winderlich pers comm. 2001). Dugongs are of cultural significance to the Quandamooka community of North Stradbroke Island in Moreton Bay (Figure 6.6). Discussions with the dugong hunting group at North Stradbroke Island indicate that at least 30 dugongs have been hunted in Moreton Bay over the last 10 years. There is also information that some unrecorded poaching by other hunters has also occurred (Lemm pers comm. 2001). There is currently a Native Title Claim on some of the islands and waters in Moreton Bay and the adjacent land. In addition, Native Title claims also exist over various parts of the Great Barrier Reef (Stokes pers comm. 2001). |
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| Boat-related Impacts and Ecotourism | ||
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Boating activities potentially impact seagrass beds along the urban coast of Queensland. Boat traffic causes disturbance
to dugongs in the surrounding waters and may degrade dugong habitat. In addition, direct impacts to dugongs occur
through boat strikes and from cuts caused by propeller blades. These concerns are greatest in areas of high
recreational use such as the Hinchinbrook Island area, Cleveland Bay, Hervey Bay and Moreton Bay (Figure 6.6).
Eleven dugong mortalities from boat strikes have been recorded in the Queensland Wildlife Stranding and Mortality
Data Base since 1996 (Haines & Limpus 2000). In September 2001, a dead dugong was discovered on the southern end
of Lamb Island, Moreton Bay (towards the southern end of North Stradbroke Island; Figure 6.6). A number of
propeller marks were evident along its body. A commercial dugong watching operations is permitted to operate
in Commonwealth waters in the Hinchinbrook Island region. Other operators in significant dugong habitat along
this coast provide passengers with opportunities to observe dugongs on an incidental basis. |
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| Chemical Pollution | ||
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Tissue samples of liver and blubber were salvaged from 53 dugong carcasses stranded along the Queensland coast between
1996-2000 as part of the Queensland Necropsy Program. Liver tissue was analysed for a range of heavy metals and
blubber samples were analysed for organochlorine compounds and polychlorinated biphenyls (Haynes et al. in review).
Concentrations of toxic metals were generally low and in the range typically found in marine mammals. Average metal
concentrations were generally higher in mature animals and elevated concentrations of chromium and nickel were
detected in liver samples from several animals collected from the southern Queensland coast. Dieldrin, DDT and/or
DDE and/or heptachlo-epoxide were detected in 59% of dugong blubber samples. Concentrations of organochlorines
were similar to those reported being present in dugongs 20 years earlier, and were low in comparison to
concentrations recorded from marine mammal tissue collected elsewhere in the world. Polychlorinated
dibenzodioxins (PCCDs) appear to be the most significant organochlorine pollutant bioaccumulated in dugongs
(Haynes et al. 1998; Haynes et al. in review). Coastal contamination for dugongs in this region are likely to
be indirect through herbicide impacts to near-shore seagrass beds (Haynes et al. 2000a and b; Haynes et al. in review). |
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| Disease | ||
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Necropsies conducted on sick, injured or dead dugongs reported to the Queensland Parks and Wildlife Service
indicate that disease is the cause of death for 30% of the 80 animals for which the cause of death has been determined
since 1996 (Haines & Limpus 2000). Haines and Limpus (2000) hypothesise that inter-annual fluctuations in dugong
mortality are related primarily to the negative impact of abnormal wet seasons on seagrass pasture quality and a
resultant deterioration on the dugong's health status. |
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| Existing Conservation Initiatives | ||
| Legislation | ||
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The dugong is protected under the Commonwealth Environment Protection and Biodiversity Conservation Act, 1999 and
the Queensland Nature Conservation Act 1992. A Nature Conservation (Dugong) Conservation Plan for Queensland
waters was adopted in 1999. |
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| Research | ||
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Dugong research in this region began with the study of carcasses in the late 1960s (Heinsohn 1972). These studies
formed the basis of modern understanding of dugong anatomy (e.g. Spain & Heinsohn 1974, 1975; Spain et al. 1976;
Marsh et al. 1978; Marsh & Eisentraut 1984; Rowlatt & Marsh 1985), life history (Marsh 1980; Marsh et al.
1984 a,b,c), diet (Heinsohn & Birch 1972; Spain & Heinsohn 1973; Marsh et al. 1982) and heavy metal status
(Denton et al. 1980). Aerial surveys for dugongs have been conducted in the region since the 1970s (Heinsohn
et al. 1978; Marsh & Saalfeld 1989; Preen 1992; Marsh et al. 1996; Lanyon & Morrice 1997; Marsh & Lawler 2001a).
Most of our knowledge of dugong-seagrass interactions (Preen 1995; Preen & Marsh 1995; Marsh et al. 1998; Aragones
& Marsh 2000) and movements (Marsh & Rathbun 1990; Preen 2001) has come from this region. In 1999 the Great
Barrier Reef Ministerial Council accepted a Dugong Research Strategy (Oliver & Berkelmans 1999) as a guide
to setting priorities, allocating funds and assessing performance of dugong recovery and conservation actions
in the Great Barrier Reef and Hervey Bay-Great Sandy regions. The Department of Defence has commenced the formal integration and management of its Dugong Research Program for the Shoalwater Bay Military Training Area (SWBMTA). The Department of Defence plans to fund dugong research in the form of four independent projects:
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| Management | ||
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Most of the dugongs and their habitats on the urban coast of Queensland occur in marine parks: the Great Barrier Reef
Marine Park and the associated Queensland Marine Parks in the Great Barrier Reef region, the Hervey Bay Marine Park
and the Moreton Bay Marine Park. In 1997 the Australian and Queensland governments agreed to several measures specifically aimed at arresting the decline of dugongs along the urban coast of Queensland, including a resolution not to issue permits for the indigenous hunting of dugongs from Cooktown down to the southern border of the Great Barrier Reef Marine Park. The most controversial measure was to establish a two-tiered system of Dugong Protection Areas (DPAs) (Figure 6.6). Gill and mesh netting are greatly restricted or banned in seven Zone A DPA's totalling 2,407km2, and subject to lesser modifications in eight Zone B DPA's totalling 2,243km2 (Fisheries Amendment Regulation [No. 11] 1997 [Queensland]). An additional Zone A DPA of 1703km2 in which gill and mesh netting practices were modified was established in Hervey Bay (Marsh 2000). A conservation plan for dugongs in Queensland was implemented by the Environmental Protection Agency in 1999. This plan further reinforced the functions of the Dugong Protection Areas (DPA's). There is concern that boat racing, water skiing and jet skiing place dugongs at risk from vessel strikes and noise in the Hinchinbrook Island region (Figure 6.6). The Great Barrier Reef Ministerial Council has developed transit lanes with marker buoys to designate a voluntary 25 knot speed limit transit lane and a 10 knot speed restriction zone within identified important dugong feeding areas or on observing a marine animal at close range (GBRMPA 2001). Other proposed strategies outlined in the Draft Hinchinbrook Plan of Management (2001) to protect marine mammals include the introduction of a maximum overall length of 20m for all vessels in Missionary Bay; prohibiting aircraft to land, depart or taxi in any location of the Hinchinbrook Island Dugong Protection Area (Figure 6.6); and the requirement of tourism operators to operate in accordance with booking limits to the Planning Area and sensitive location restrictions (GBRMPA 2001). In addition, the Council has requested the Queensland Parks and Wildlife Service to refuse requests for permits to conduct boat races in excess of 40 knots in the Hinchinbrook Zone A DPA (Figure 6.6). This issue is to be addressed in the Cardwell/Hinchinbrook Regional Coastal Management Plan. Signs have been placed at boat ramps in the DPAs informing boaters about DPA areas and regulations. An education campaign is underway to seek a voluntary reduction in boat speeds in shallow waters. 'Sunfish', which represents recreational fishing interests, has published a 'Code of Conduct' with suggested measures to minimise boat strikes on dugongs. In its 1999 review of measures for dugong conservation, the Ministerial Council also directed that a strategy be developed to form cooperative management agreements with indigenous communities; welcomed a commitment from the Queensland Government to pursue to efforts to minimise the impact of land-based activities on DPAs; and upgraded procedures for responding to reports of stranded dugong including refining processes to establish 'cause of death' and fast release of information to the public. The Department of Defence has agreed to a moratorium on the use of explosives in all DPAs along the coast, except the Shoalwater Bay Military Training Area. The Department of Defence has ceased underwater detonation activities in important seagrass meadows near Triangular Island in Shoalwater Bay, and has altered other practices to minimise their risk to dugongs. In July 1999 the Great Barrier Reef Ministerial Council endorsed negotiations to secure a phasing out of the use of high explosives within the GBR World Heritage Area. In 1997, the Great Barrier Reef Marine Park Authority finalised a plan of management for dugong conservation in Shoalwater Bay. Plans of management for the major tourist regions of Cairns and the Whitsundays were finalised in 1998. A plan of management for the Hinchinbrook region is in preparation. These plans include protective measures for dugongs. The Moreton Bay Marine Park covers most of the Bay's tidal lands and tidal waters seawards to the limit of Queensland waters. There are five areas designated as "turtle and dugong" areas. Within these areas there are speed regulations which state that boat operators are not permitted to motor their boats on the plane. A publicity campaign was launched to assist in informing boaters of the new regulations. A Moreton Bay Dugong Watch monitoring program was launched in March 1998. An education and information program has been developed by the Great Barrier Reef Marine Park Authority to enhance public awareness of the value and plight of dugongs, and to advise people on how they can assist in minimising impacts. The program includes information kits, media releases, community service announcements, reef user workshops and liaison with advisory committees and interest groups. The Fishing Industry Training Council in conjunction with the Queensland Seafood Industry Council and scientists have set up an Endangered Species Awareness Course. The industry encourages this course as a prerequisite for holding a license for commercial net fishing. All fishers operating in the Dugong Protection Areas are expected to participate in this course. |
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| Suggested Conservation Initiatives | ||
| Research | ||
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The goal of research in this region is to acquire information to assist in the recovery and maintenance of dugong
populations. A series of research projects have been identified, which reflect a wide range of priorities among
managers, researchers and stakeholders with interests in dugongs. These projects have been incorporated into the
Dugong Research Strategy for the Great Barrier Reef World Heritage Area and Hervey Bay (Oliver & Berkelmans 1999). The categories include:
The CSIRO Division of Marine Research has reviewed the status of fisheries-related seagrass research within Australia for the FRDC (Fisheries Research and Development Corporation). The research and development plan (Butler & Jernakoff 1999) includes various recommendations for seagrass research priorities. Of particular concern in this region is the lack of knowledge on the relationship between human activities and the effects of nutrient loading on seagrass beds. |
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| Management | ||
| Habitat Protection | ||
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The DPA strategy depends on high priority being given to habitat protection in these areas. The effectiveness of the
mesh netting closures and restrictions depends on there being no overall movement of dugongs from the DPAs to other
areas. To minimise the risks of this happening, it is particularly important to conserve dugong habitat, especially
in the DPA Zone A's. The relevant management agencies should collectively review the zoning of the relevant sections of the Great Barrier Reef Marine Park, State Marine Parks and Fisheries Habitat Areas with a view to assessing their capacity to protect dugongs and their habitats. Key areas such as the Hinchinbrook Island area, Cleveland, Shoalwater, Hervey and Moreton Bays should be the focus of this review. The Great Barrier Reef Marine Park Authority is reviewing the protection of inshore habitats in the Great Barrier Reef Marine Park in association with their Representative Areas Program. This initiative will provide rigour in the selection of seagrass and dugong habitat for inclusion in highly protected zones in the marine park. The Great Sandy Region Management Plan 1994 recommends extensions of existing marine parks to include all appropriate tidal lands and waters in the area. If adopted, the resulting marine park will be zoned in consultation with user and interest groups, and will enhance the prospect of dugong survival in the area. Seagrasses and mangroves are given specific protection in Fisheries Habitat Areas under Section 123 of the Fisheries Act 1994 where all marine plants are protected, and can only be damaged or removed under permit (Section 51(c)). |
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| Indigenous Management | ||
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Although some indigenous communities have agreed to a moratorium on hunting in the Southern Great Barrier Reef region, there is still a strong desire within the indigenous communities to hunt dugongs as they are of considerable cultural, social and economic importance. Indigenous communities in this region have made it clear that they will not give up their native title rights to hunt dugongs and they wish to have these rights formally recognised by governments through the development of cooperative management arrangements. The need for the development of cooperative management arrangements for marine resources between management agencies and indigenous peoples is recognised by all parties. The success of cooperative management arrangements will involve communities being a full partner in all stages of the management process, bringing together traditional owners, science and management. The next step in this process is a formal agreement between the State and Commonwealth, which will need to provide the resources required to operationalise cooperative management. In order to develop a better understanding of small-scale population changes in dugong populations near indigenous communities, community-based dugong watch programs could be developed incorporating local expertise, provided personnel are available to coordinate such programs. This activity would contribute to developing appropriate mechanisms and tools for integrating local knowledge and scientific data. |
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| Fishery Interactions | ||
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The effectiveness of the mesh netting restrictions and attendance rules implemented in 1998 in the DPA's needs to be
monitored. It is important to note that a significant proportion of dugongs along the urban coast of Queensland occur
outside these DPAs (Marsh 2000). Therefore management regimes for areas within the dugong's area of occupancy but
outside the DPA's need to be considered if the objective of management is to minimise human impacts on dugongs. We support the following initiatives to maximise the effectiveness of fishing closures in the DPA's:
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| Conclusions | ||
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