Management Program for the Saltwater Crocodile - in the Northern Territory of Australia, 2012-2014
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Management Program
for the Saltwater Crocodile
in the Northern Territory of Australia, 2012-2014
Photograph: Tourism NT
Management Program for the Saltwater Crocodile in the Northern Territory of Australia, 2012 - 2014 Parks and Wildlife Service of the Northern Territory Department of Natural Resources, Environment, The Arts and Sport PO Box 496 Palmerston NT 0831 Northern Territory of Australia First Published 2009 Revised Draft for public comment June 2012 This work is copyright. It may be reproduced for study, research or training purposes subject to an acknowledgment of the sources and no commercial usage or sale. Requests and enquires concerning reproduction and rights should be addressed to the Chief Executive, Department of Natural Resources, Environment, The Arts and Sport, PO Box 496, Palmerston NT 0831, Australia. Citation Leach G.J., Delaney R. and Fukuda, Y. (2009). Management Program for the Saltwater Crocodile in the Northern Territory of Australia, 2009 - 2014. Northern Territory Department of Natural Resources, Environment, the Arts and Sport, Darwin. A management program prepared under the Territory Parks and Wildlife Conservation Act. Program Approval The Management Program for the Saltwater Crocodile in the Northern Territory of Australia, 2012-2014 Approved by the Administrator for the Northern Territory as an approved management program under Section 34(2) of the Territory Parks and Wildlife Conservation Act on XXXXXXX. Approved by the Minister for Sustainability, Environment, Water, Population and Communities as an Approved Wildlife Trade Management Plan under Subsection 303FO(3) of the Environment Protection and Biodiversity Conservation Act 1999 on XXXXXXX. Approval of this program is valid until 31 December 2014.
Contents
Definitions and Acronyms ...................................................................................................... 1
1. Introduction .............................................................................................................. 3
1.1 Aims and Objectives ................................................................................................ 5
1.2 Species.................................................................................................................... 5
1.3 Responsible authority .............................................................................................. 5
1.4 Legislative, national and international obligations .................................................... 5
1.4.1 Northern Territory ......................................................................................... 5
1.4.2 Commonwealth Government ........................................................................ 7
1.4.3 International ................................................................................................. 7
2. Management context ....................................................................................................... 9
2.1 Socio-economic values ............................................................................................ 9
2.1.1 Cultural values ............................................................................................. 9
2.1.2 Economic ..................................................................................................... 9
2.2 Population estimates and trends .............................................................................11
2.3 Saltwater crocodile habitat ......................................................................................12
2.3.1 Protected areas ...........................................................................................12
2.3.2 Significant wetlands outside reserves ..........................................................14
2.4 Problem saltwater crocodiles ..................................................................................14
2.5 History of use..........................................................................................................15
2.5.1 Indigenous harvest and use ........................................................................15
2.5.2 Commercial harvesting and use ..................................................................15
3. Threats and impacts .......................................................................................................15
3.1 Natural predators ....................................................................................................16
3.2 Drought, flood and climate change .........................................................................16
3.3 Habitat loss and modification ..................................................................................16
3.4 Entanglement in fishing nets ...................................................................................17
3.5 Disease ..................................................................................................................17
3.6 Harvesting – general...............................................................................................17
3.6.1 Harvesting – genetic....................................................................................17
3.6.2 Harvesting - impacts on other species, habitats and ecosystems ................17
4. Management practices and performance measures ......................................................18
Objective 1 - To facilitate the sustainable use of Saltwater Crocodiles............................18
4.1 Commercial harvest and use ..................................................................................18
4.2 Permits and compliance..........................................................................................24
4.3 Management-focused research ..............................................................................28
Objective 2 - To promote community awareness and public safety .................................28
4.5 Removal of problem crocodiles ...............................................................................29
4.6 Community awareness and participation ................................................................35
Objective 3 - To ensure humane treatment of Saltwater Crocodiles................................36
4.7 Animal welfare ........................................................................................................36
Management Program for the Saltwater Crocodile in the Northern Territory iii
Objective 4 - To monitor and report on the impact of the harvest of
Saltwater Crocodiles……………………………………………………………………………36
4.8 Monitoring ...............................................................................................................36
4.9 Reporting ................................................................................................................39
5. References .............................................................................................................40
Appendix 1: Saltwater Crocodile Background Information ..............................................44
Appendix 2: Farm Management ......................................................................................49
Appendix 3: Saltwater Crocodile Densities In The Rivers Monitored In The Northern
Territory .......................................................................................................51
Appendix 4: Annual Milestone Matrix for 2012-2014 Program .........................................58
Appendix 5: Draft Guidelines for the Safari Hunting of Crocodiles in the Northern
Territory .......................................................................................................62
Management Program for the Saltwater Crocodile in the Northern Territory ivDefinitions and Acronyms Adults Animals greater than 7 feet (approx. 2.1 metres) total length are classed as adults. This is a defined size class for the purpose of this Management Program and does not equate to sexual maturity. CITES Convention on International Trade in Endangered Species of Wild Fauna and Flora Crocodile Products and By-products Includes all parts from a crocodile except for skins as defined below. Crocodile Skins Includes raw or tanned belly skins (cut along the back), hornbacks (cut along the belly) and whole skins. Egg Harvest The physical removal of an egg from its natural location in the wild and transportation to another location. Eggs Unless otherwise stipulated includes all eggs regardless of whether it is fertile or infertile, with a live or dead embryo. Eggs - dead Eggs that are infertile or contain a dead embryo and/or discarded before placement in an incubator. Eggs - live For the purposes of this Management Program these are eggs initially placed into an incubator. Eggs - viable Eggs that produce a normal hatchling surviving at least one day outside the egg. EPBC Act Environment Protection and Biodiversity Conservation Act. Commonwealth legislation. Harvest Ceiling The Northern Territory’s annual maximum allowable number of individuals that can be harvested in each of the defined life stages. Management Program for the Saltwater Crocodile in the Northern Territory 1
Hatchling Animals classed as hatchlings are ‘Young-of-the-year’ and typically less than 2 feet (approx. 0.6 metres) total length. Juvenile Animals classed as juveniles are between 2 and 7 feet (approx. 0.6 – 2.1 metres) total length. NRETAS Northern Territory Government Department of Natural Resources, Environment, The Arts and Sport. Ranching As used in the context of CITES, it is the rearing in a controlled environment of specimens taken from the wild. RDPIFR Northern Territory Government Department of Regional Development, Primary Industry, Fisheries and Resources. Regional Catchment Catchment(s) as defined in Australian Surface Water Management Area (2000) that are grouped for monitoring the crocodile harvest in the Northern Territory. Total Length Animal length measured from the tip of the snout to the end of the tail. TPWC Act Territory Parks and Wildlife Conservation Act. Northern Territory legislation. Management Program for the Saltwater Crocodile in the Northern Territory 2
1. Introduction Saltwater Crocodiles are and always have been serious predators. Co-existing with crocodiles does present challenges to the Territory community. On the other hand, crocodiles also provide significant opportunities. They are a valuable resource to both Indigenous and non-Indigenous people in northern Australia. A lucrative and uncontrolled trade in saltwater crocodile skins between 1945 and 1971 stimulated intensive hunting that depleted the wild populations to the point of extinction. It was unclear whether the remaining crocodile population had the capacity to recover when full protection of the species was introduced in 1971. By 1979/80, when the population had increased from an estimated base of 5,000 to around 30,000 (Webb et al 1984), a series of fatal and non-fatal attacks occurred in 12 months, along with an increase in other incidents such as attacks on fishing boats. These negative interactions with people threatened the conservation program, which was aimed at rebuilding the wild population back to carrying capacity. Some people opposed any further expansion of crocodile numbers and widespread culling was actively promoted. In the early 1980s the Northern Territory Government implemented an “incentive-driven conservation” strategy, to inform the public of the environmental and economic benefits of crocodile conservation. Positive incentives were created through commercial activity (tourism, crocodile farming and ranching) and negative incentives countered by an active ‘Problem Crocodile’ control program. In such an “incentive-driven conservation program”, there are two fundamental approaches. The first is to ensure that conservation objectives are being met, and the second is to ensure the incentives for conservation are maintained. It is not a case of ‘conservation versus development’ but rather both benefiting from successful conservation. Ranching of eggs (the commercial collection of eggs from the wild and raising into hatchlings) was considered to be the safest strategy for sustainable use to reward landowners for tolerating crocodiles. This is because the egg stage is an abundant and naturally vulnerable part of the life cycle. Furthermore, it resulted in nesting habitat on private lands becoming a commercial asset worth protecting. In 1985 Australia was successful in having its population of Saltwater Crocodiles transferred from Appendix I to Appendix II of Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES) specifically for ranching so that farms could export the skins produced from the harvested eggs they bought from landowners. In 1987, the first NT crocodile management program was approved by the Commonwealth and skins derived from the ranching program began to be exported. In 1994, Australia obtained an unrestricted Appendix II CITES listing to allow landowners with crocodiles, but no nesting habitat, to also receive commercial benefits from crocodiles through a wild harvest. The Northern Territory Government has fostered the crocodile farming industry and in recent years the NT industry has significantly invested in crocodile farming infrastructure to increase their capacity. The resultant increased competition for eggs has increased prices for landowners, including for Aboriginal people in remote areas where opportunities for economic development are sometimes limited. Skin exports are rising and are predicted to rise sharply in future years. This incentive-driven wildlife program has been a major conservation success story that is seldom played out with large and dangerous predators anywhere in the world. Saltwater Crocodiles are no longer a threatened species in the NT and have recovered such that they Management Program for the Saltwater Crocodile in the Northern Territory 3
are now abundant. Saltwater Crocodiles are viewed as a valuable commercial resource,
generating wealth and employment which promotes their conservation. The continuation of a
viable and economic crocodile farming industry is recognised as the key economic driver for
this Management Program. The tourism value of crocodiles both in the wild and in captivity
also generates economic activity around the presence of crocodiles in the landscape. The
economic value of the crocodile egg harvest is also resulting in environmental gains through
improved management practices for weeds, feral animals and fire by landowners to favour
crocodile nesting habitat. The Management Program through incentive driven conservation,
explicitly encourages management practices that favour the Saltwater Crocodile and protects
wetland habitats beyond the boundaries of parks and reserves.
Through this Management Program and other strategies, the Northern Territory Government
will continue to assist industry to maximise the investment, commercial activity and
employment generated through crocodiles so that the industry maintains its role as a well
recognised and supported part of the NT economy. The farming industry vision is for the
Northern Territory to grow as a world leader in the reliable production of the highest quality
Saltwater Crocodile skins.
Actions that favour retaining a high abundance of a dangerous predator such as Saltwater
Crocodiles bring a heightened responsibility for public awareness and education. The changing
circumstances that drove the need for the revised Management Program include:
i) An increase in the number of landowners wanting to participate in the crocodile
industry;
ii) An increasing crocodile population;
iii) An expansion of farming capacity;
iv) A recognition that previous harvest levels have not been detrimental to the species;
v) An increase in the negative interactions between crocodiles and people; and
vi) An increasing need for public awareness about crocodiles.
This Management Program addresses the balance that is required between conservation
goals, sustainable harvest, growing industry, and maintaining public safety. It focuses on
mechanisms to improve public awareness and safety, on population dynamics, harvest limits
and monitoring the impact of the harvest on population trends.
Management Program for the Saltwater Crocodile in the Northern Territory 41.1 Aims and Objectives The aim of this management program is: To ensure the long-term conservation of the Saltwater Crocodile and its habitats in the Northern Territory. The program has four principal objectives: 1. To facilitate the sustainable use of Saltwater Crocodiles; 2. To promote community awareness and public safety; 3. To ensure the humane treatment of Saltwater Crocodiles; and 4. To monitor and report on the impact of the harvest of Saltwater Crocodiles. 1.2 Species The Saltwater Crocodile (Crocodylus porosus Schneider) is one of two species of crocodile found in Australia; the other being the smaller Freshwater Crocodile (Crocodylus johnstoni). Subspecies or races have not been described. Further details on the status and ecology of the Saltwater Crocodile are provided in Appendix 1. 1.3 Responsible authority The Northern Territory Government through the Department of Natural Resources, Environment, The Arts and Sport (NRETAS) manage wildlife in the Northern Territory pursuant to the Territory Parks and Wildlife Conservation (TWPC) Act. The control of all aspects of the harvest from the wild in the Northern Territory is administered under this legislation. Once animals are contained in a farm, the Department of Regional Development, Primary Industry, Fisheries and Resources (RDPIFR) has the administrative role for crocodile farming. These responsibilities are outlined in Appendix 2. 1.4 Legislative, national and international obligations 1.4.1 Northern Territory Territory Parks and Wildlife Conservation (TPWC) Act The TPWC Act contains provisions for the management and conservation of native animals including Saltwater Crocodiles. The Saltwater Crocodile is classified as protected wildlife throughout the Northern Territory under Section 43 of the TPWC Act. Section 66 of the Act prohibits the taking or interfering with protected wildlife without a permit issued by the Director of the Parks and Wildlife Commission or their delegate. It is also an offence under Section 66 of the Act to possess or trade in live or dead crocodiles, crocodile eggs or parts of crocodiles without a permit. The Saltwater Crocodile is not classified as threatened in the Northern Territory. It has recovered from the very low population numbers in the 1970s to now being considered a widespread and abundant species and not of any conservation concern. It is an offence to possess live Saltwater Crocodiles or their eggs except in accordance with a permit issued under Section 43 of the TPWC Act by the Director of the Parks and Wildlife Commission or their delegate (Section 66(2)). Management Program for the Saltwater Crocodile in the Northern Territory 5
Permits to possess and/or trade in crocodiles may be issued by the Director of the Parks and Wildlife Commission or a delegate in accordance with Sections 55, 56 and 57 of the TPWC Act. The Director may under Section 57 of the Act apply terms, conditions or limitations to the permit to regulate the harvesting and farming of crocodiles. The taking of wildlife by Aboriginal people for traditional purposes, including food, is provided for under Section 122 of the TPWC Act. Aboriginal people are not bound by hunting regulations or seasons when taking animals for food or other traditional purposes. Animal Welfare Act The Animal Welfare Act ensures that animals are treated humanely; cruelty to animals is prevented and community awareness about the welfare of animals is promoted. Crocodiles held in captivity under permit are classified as stock animals under the Animal Welfare Act and persons must not neglect, or commit an act of cruelty that causes an animal unnecessary suffering. Code of Practice on the Humane Treatment of Wild and Farmed Australian Crocodiles Animal welfare standards for crocodiles are detailed in this Code. All crocodiles must be managed in accordance with this Code. http://www.environment.gov.au/biodiversity/trade-use/publications/crocodile-code-of-practice.html Environmental Assessment Act New developments for the farming, processing and display of crocodiles will need to meet the requirements of this Act. Meat Industries Act Farmed crocodiles may be slaughtered in abattoirs licensed for the slaughter of crocodiles. In addition, the Saltwater Crocodile was declared as a game animal on 10 June 2004 (G24) under the Meat Industries Act which enables crocodiles killed in the wild to be slaughtered for human consumption in licensed game meat abattoirs according to the national code of practice for the slaughter of game animals. Food Act Crocodile meat is sold for human consumption and this Act provides for the safety and suitability of food for human consumption. Livestock Act Farmed crocodiles are treated as livestock under this Act which provides for disease surveillance, disease control, identifying and tracing animals and regulating movement of animals and animal products for the purpose of disease control Integrated Natural Resource Management Plan for the Northern Territory: sustaining our resources – people, country and enterprises. This Northern Territory Government endorsed plan provides the broad framework and a series of actions directly contributing to the conservation of Saltwater Crocodile habitat and for the sustainable use of wildlife such as Saltwater Crocodiles. Management Program for the Saltwater Crocodile in the Northern Territory 6
1.4.2 Commonwealth Government Environment Protection and Biodiversity Conservation (EPBC) Act The EPBC Act regulates imports and exports to and from Australia of all Australian native animals or their parts. The Saltwater Crocodile is a listed marine species under the EPBC Act. This protects the species and limits the circumstances under which they may be taken. Part 13A of the EPBC Act regulates imports and exports of crocodiles and crocodile products. It also fulfils Australia’s legislative requirements as a signatory party to CITES (see 1.4.3). Section 303CH lists specific conditions that must be met for the export or import of CITES specimens. For CITES Appendix II exports the specimen must be sourced from an appropriate captive breeding or artificial propagation program, an approved wildlife trade operation, or an approved wildlife trade management plan. This Northern Territory Management Program meets the requirements of the EPBC Act for both international and national activities with Saltwater Crocodiles. This management program therefore complies with an approved Commonwealth wildlife trade management plan pursuant to Section 303FO of the EPBC Act. Commercial export permits for crocodiles are issued under Section 303CG. A State/Territory management program for wild populations is not required if a State/Territory elects to limit use to captive breeding. However, even crocodile farms based solely on captive breeding in Australia have to be registered under the EPBC Act before permission to export products is granted. Aboriginal Land Rights (Northern Territory) Act This Act establishes the Land Councils. A function of the Land Councils is that they confirm the correct landholders (traditional owners) have given their permission for any commercial wildlife harvest before TPWC Act permits can be issued. This Act also provides for Section 19 Land Use Agreements which should be in place for commercial crocodile harvesting. These agreements can provide the conditions of access to land for the purpose of harvesting and there should be consistency between ALR Act Land Use Agreements and TPWC Act permits. 1.4.3 International Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) All Crocodilians (including alligators, caimans and true crocodiles) are listed on the Appendices of CITES to which Australia is signatory. Those species most threatened in the wild by trade are listed on Appendix I and all remaining species are listed on Appendix II. In most countries C. porosus is listed on Appendix I. However the Australian, Indonesian and Papua New Guinean populations are included in Appendix II which allows international trade subject to the provisions of CITES. The Appendix II listing places controls on international trade in crocodiles and crocodile products through export permits. A CITES export permit is required for all commercial exports and can only be issued if it has been determined that the export will not be detrimental to the survival of the species and that the specimen was legally obtained. Management Program for the Saltwater Crocodile in the Northern Territory 7
Convention on Wetlands of International Importance (Ramsar Convention) Australia is also a signatory to the Ramsar Convention. There are plans of management for two of the three Ramsar-listed areas of the Northern Territory (Stages one and two of Kakadu National Park) which protect wetlands and their dependent fauna, including Saltwater Crocodiles. NRETAS is currently developing a plan of management for Cobourg Peninsula (Garig Gunak Barlu National Park). Management Program for the Saltwater Crocodile in the Northern Territory 8
2. Management context
2.1 Socio-economic values
In the Northern Territory, crocodiles are an iconic species that attract considerable publicity
and a wide range of community views and opinions regarding their abundance, distribution
and cultural and economic importance. Public and political will to continue conserving
crocodiles and their habitats is closely linked to the net community value of crocodiles being
positive.
2.1.1 Cultural values
The importance of crocodiles in Aboriginal culture is reflected in a complex system of totems
and ceremonies which is still evident among most coastal Aboriginal communities in northern
Australia today (Lanhupuy 1987). Aboriginal communities also regard Saltwater Crocodiles
as dangerous animals. The non-Indigenous community has a diversity of views on Saltwater
Crocodiles from being reviled and seen as dangerous pests to being admired and recognised
as having a significant and rightful place in the natural world. Crocodiles are an important
natural resource for many sectors including Aboriginal communities, the tourist industry and
the crocodile farming industry.
2.1.2 Economic
Harvesting
The harvesting of crocodiles primarily for their skins but also for their flesh and body parts
supports a significant industry in the Northern Territory.
The Northern Territory Government determines the sustainable limits of the harvest and
submits the Management Program to the Australian Government for endorsement (see
section 1.4.2). The landholder has control over access to the resource. The landholder can
therefore decide to:
• allow or not allow harvest
• conduct their own harvest or give approval for a third party to conduct the harvest
• determine the level and form of payment for access to the resource
• determine any conditions (within legal requirements) they wish to impose on access to
the resource.
Egg harvest
The mainstay of the crocodile farming industry is the harvest of eggs from the wild under an
annual ranching program. This harvest has operated continuously since the first small trial
harvest was conducted in the 1983/84 nesting season. The annual harvest of 50,000 live
eggs provides a significant employment and commercial opportunity to landholders, in
particular remote Indigenous communities. Although some farms maintain a capacity for
captive breeding, the number of eggs generated from captive breeding is less than the wild
harvest. During the life of this program, the wild harvest of eggs will continue to be the
predominant form of harvest.
Management Program for the Saltwater Crocodile in the Northern Territory 9Animal harvest In 1994 all restrictions and conditions on the CITES listing of the Australian population of Saltwater crocodile were removed, which allowed commercial harvesting to expand from the ranching of eggs to the take of hatchlings, juveniles and adults. However, the commercial interest in the harvest of these stages has been small. For example, although there was a quota in the previous Management Program for 500 adults, the commercial take of adults has been less than 100 animals each year for the last six years. The previous plan was approved subject to the safari hunting component being removed. This plan proposes that 50 of the 500 adults be taken for safari hunting. Safari hunting is a specialised form of wild animal harvest where a paying client undertakes the harvest. The Northern Territory Government supports safari hunting, particularly in remote areas, and recognises that it must be strictly controlled with all activities conforming to the highest possible standards of animal welfare and stewardship of the environment. During the life of this Management Program the Northern Territory Government will trial a framework for safari hunting with an emphasis on the opportunities for Indigenous participation, employment and benefit. Benefits to landholders that flow from safari hunting of crocodiles will be considerable, particularly for Aboriginal landholders and those who currently host or run their own pig, banteng and buffalo safari hunting operations. Safari hunting of banteng, buffalo and pigs already attracts local and interstate hunters who pay not only trophy fees but also for accommodation and other expenses. Safari hunting operations currently provide trophy fees of up to $1,500 per buffalo and $2,900 per banteng to Aboriginal landholders. Further, safari operations on Aboriginal land may provide employment opportunities for Aboriginal landholders in safari operations; either those run by third-party operators or by Indigenous groups. The inclusion of crocodile safari hunting is expected to increase domestic and international interest in the Northern Territory’s existing safari hunting industry. Safari hunting of crocodiles will increase the financial benefits of the current wild harvesting program and will provide a much greater return per animal than other wild harvesting. Safari hunting of crocodiles is projected to provide trophy fees of $5,000 to $10,000 per crocodile to landholders (Indigenous and non-Indigenous). Crocodiles taken by safari hunters will be taken within the current quota for wild harvesting of adult crocodiles. Given the financial gains that are likely to accrue, it is expected that safari hunting will increase the incentive for landholders to protect crocodiles and crocodile habitats. Safari hunting should not be used as a means of controlling problem crocodiles. The Northern Territory’s crocodile management program provides an incentive for Aboriginal communities and land managers to conserve crocodile breeding habitats through payments to landholders by harvesters for each egg or animal collected from their property. There is a small demand for crocodiles as pets and legally acquired stock can be held as pets under a set of special conditions. A permit to keep is required as detailed under section 4.2.2. Farming The NT position in the world market for farmed crocodile skins is small but occupies an important and significant niche in supplying premium grade skins for high end market fashion accessories. Between 2003 and 2007 the Northern Territory exported on average Management Program for the Saltwater Crocodile in the Northern Territory 10
approximately 6,000 skins per year both interstate and internationally. Recent farm
infrastructure expansion and increasing holdings of animals indicates this number will
increase significantly. The meat and other products of crocodiles such as teeth and skulls are
also marketed. Whilst the farming industry is small in number of businesses, it is substantial
in economic output with an annual turnover in the order of several tens of millions of dollars.
There are currently six functional crocodile farms in the Northern Territory, which collectively
held approximately 86,000 non-hatchling C. porosus as at end of December 2008. The
Northern Territory crocodile industry currently directly employs between 60 – 100 people.
Tourism
Crocodiles contribute significantly to visitor knowledge of the Top End and viewing crocodiles is
an important expectation or even a “must” for most Top End visitors. In visitor surveys,
Tremblay (2003) reported that seeing crocodiles dominates the best experiences in wildlife-
viewing. While tourists generally prefer to see crocodiles in the wild and this is an increasingly
sought after experience, attractions featuring captive crocodiles are also rated highly and are
popular destinations. The Top End offers a wide range of experiences from observing in the
wild; modified behaviour in the wild; research/educational displays and captive encounters.
2.2 Population estimates and trends
In the Northern Territory, unregulated commercial hunting of C. porosus began in 1945 and
continued until 1971 when the species was protected due to the marked decline of the
population. After protection in 1971, the population of C. porosus in the Northern Territory
increased from approximately 3,000 non-hatchlings (individuals >0.6 m total length) in 1971
to between 30,000 and 40,000 individuals in 1984 (Webb et al. 1984). The population of wild
non-hatchling C. porosus has continued to increase and in 1994 was estimated to be
between 70,000 and 75,000 non-hatchling individuals (Webb et al. 1994).
The current survey and monitoring data provides a measure of the population trend at the
sampling sites and by extrapolation a demonstration of the trend for the total population. The
principal purpose of monitoring the wild population is to provide an objective means through
which any serious general or local decline, due to any cause, can be detected in sufficient time
to effect remedial action. The monitoring program also allows rates of change of population
size and structure (proportion of different size classes and biomass) to be quantified and
assessed, thereby providing an objective basis for adjusting harvest levels as necessary.
Details of the long-term population trends are shown in Appendix 3. These statistics do not
provide a measure of the total number in the population nor is such a statistic required for
management purposes.
The population of Saltwater Crocodiles in the Northern Territory continues to increase as
demonstrated by the trend in the pooled data from monitored rivers (Figure 1) and individual
rivers (Appendix 3). In some rivers rates of increase have recently slowed and may be
approaching relatively stable levels (Delaney et al. 2008; Fukuda et al in prep). There is no
suggestion that population trends differ among rivers in catchments that are unharvested,
partially harvested, or subject to harvest throughout their area (Appendix 3).
The continuing increase in the Saltwater Crocodile population is also demonstrated by:
• The biomass of crocodiles in some of these rivers continues to increase, including rivers
in which increase in numbers is levelling off (Appendix 3). This is consistent with the
Management Program for the Saltwater Crocodile in the Northern Territory 11expectation of the maturing size and age structure of a large, slow-growing species that
is recovering from the threshold of extinction in the 1970s.
• The distribution of Saltwater Crocodiles is expanding upstream to recolonise accessible
freshwater habitats in the Northern Territory (Letnic and Connors 2006).
• There is an increase in the number of crocodiles that are living in other marginal habitat,
such as the coasts and seas (Nichols and Letnic 2008).
• The number of crocodiles removed from the ‘Intensively Managed’ zone in the Darwin
Harbour has increased in recent years (Section 2.4), indicating that animals in expanding
populations continue to disperse in search of living areas (Delaney et al. 2008).
16.00
14.00
12.00
10.00
Non-hatchling density
8.00
6.00
(sightings/km)
4.00
2.00
0.00
1970 1975 1980 1985 1990 1995 2000 2005 2010
Figure 1: Density of non-hatchling (> 2 ft (= 60 cm) including eyes-only) C. porosus calculated from standardised
spotlight surveys in 12 tidal rivers. Protection was in 1971. Closed symbols are from the Mary River and open
symbols from all other rivers.
2.3 Saltwater crocodile habitat
2.3.1 Protected areas
Formal protected areas in the Northern Territory provide a mosaic of secure areas in which
Saltwater Crocodiles and their riparian and wetland habitats are protected. They also provide
areas where the public can view and learn about crocodiles and their conservation.
Significant areas of potential suitable crocodile habitat were identified by overlaying
hydrography and vegetation layers on the reserve system boundaries in GIS
(Table 1, Figure 2).
Management Program for the Saltwater Crocodile in the Northern Territory 12Table 1: Protected areas in the NT with significant potential areas of suitable habitat for
C. porosus
Area
Name Suitable habitat (km2)
(km2)
Kakadu National Park 19 068 2 730
Mary River National Park 1 217 680
Djukbinj National Park 553 330
Garig Gunak Barlu National Park 2 063 310
Shoal Bay Coastal Reserve 121 80
Litchfield National Park 1 459 40
Vernon Islands Conservation Reserve 33 30
Harrison Dam Conservation Area 32 30
Melacca Swamp Conservation Area 23 20
Keep River National Park 314 20
Figure 2 shows the predicted favourable Saltwater Crocodile habitat in the Reserve system.
The commercial harvest of C. porosus is currently permitted within Djukbinj, Harrison Dam and
Melacca Swamp protected areas but is not permitted within Kakadu, Mary River, Shoal Bay,
Litchfield, Vernon Islands and Keep River. Saltwater Crocodiles are actively trapped from
specific sites in Nitmiluk, Flora, Shoal Bay and Litchfield National Parks as a public safety
measure.
Figure 2: Suitable Saltwater Crocodile habitat in the Northern Territory reserve system predicted from
hydrography and vegetation layers in GEODATA TOPO 250K Series 3. Suitable habitat are defined by favourable
water body types (land subject to inundation, marine swamp, saline coastal flat, swamp, perennial lake, perennial
watercourses, and mangrove) mapped to 100 km from the coastline.
Management Program for the Saltwater Crocodile in the Northern Territory 13No harvesting is permitted in Kakadu National Park so it is of particular significance as a
protected area for crocodiles given the area of suitable crocodile habitat within this Park.
2.3.2 Significant wetlands outside reserves
A major part of the range of C. porosus in the Northern Territory also lies within either
Aboriginal Lands or pastoral lands. Pastoralists, local communities and/or their legal
representatives support the maintenance of Saltwater Crocodile habitat by controlling activities
likely to be detrimental to the long-term conservation of Saltwater Crocodiles. These protocols
and restrictions offer significant protection for wetland areas.
2.4 Problem saltwater crocodiles
One of the most practical and effective responses to improve public safety is to remove
crocodiles in areas of high risk for people. Provision has been made for problem crocodile
removal in previous Management Programs and crocodiles are removed from areas where
they may cause harm to people and their property.
Problem crocodiles are defined broadly as those individuals where one or more of the
following applies:
• The crocodile has attacked or is about to attack a person or persons;
• The crocodile is behaving aggressively towards a person or persons;
• The location of the crocodile makes it a threat or potential threat to human safety or
wellbeing; or
• The activity of the crocodile is affecting the productivity of industry or commercial
enterprises.
The program allows for problem crocodiles to be killed and used directly for skin and meat
production or captured and used as stock in crocodile farms. Because released crocodiles tend
to return quite rapidly to sites of capture (Walsh and Whitehead 1993) and transport and
handling is stressful and costly, problem crocodiles are not relocated.
The number of animals that have been captured each year under the problem crocodile
program has varied over time (Table 2). This variation is likely to reflect both the increase in the
general crocodile population and fluctuations in crocodile activity between years owing to
climatic variability (Nichols and Letnic 2008). These figures include crocodiles captured from
Darwin Harbour (including Shoal Bay and some tributaries), the Darwin rural area, as well as
some from Katherine and other populated or recreation areas.
Table 2: The number of problem C. porosus removed by Parks and Wildlife staff each
financial year between 1999 and 2008.
Year Problem Crocodiles Year Problem Crocodiles
1998/1999 112 2003/2004 222
1999/2000 152 2004/2005 224
2000/2001 182 2005/2006 236
2001/2002 147 2006/2007 247
2002/2003 180 2007/2008 204
Management Program for the Saltwater Crocodile in the Northern Territory 142.5 History of use 2.5.1 Indigenous harvest and use Crocodile meat and eggs are thought to have been used as a food source by Aboriginal people for up to 40,000 years (McBryde 1979, Flood 1983). The value of eggs to Indigenous communities lay in the protein they provided to people. In the initial phases of the Northern Territory program in the 1970s nests were “bought” from landowners for 12 dozen chicken eggs to compensate for the lost nutritional value (G. Webb pers. comm.). Section 122 of the TPWC Act maintains the right for customary harvest (other than for the purpose of sale) of crocodiles and their eggs by Aboriginal people. The number of eggs and non-hatchling crocodiles traditionally harvested annually in 1990s was estimated to be around 2,000 individuals (PWCNT 1998). Based on surveys conducted in central Arnhem Land between 2003-4, the subsistence use of crocodiles in areas where they are relatively abundant is negligible (A Griffiths (NRETAS), G Wightman (NRETAS) and J Altman (ANU), pers. comm.). This outcome is similar to surveys conducted in 1980 at the same location (Altman 1987). The declining subsistence use of crocodiles is likely to be an interplay between retaining crocodiles because of their commercial value and a shift to preferred meat sources such as buffalo, pig and wallaby. No dedicated monitoring is required for subsistence use of crocodiles. 2.5.2 Commercial harvesting and use Saltwater Crocodiles were commercially hunted in the Northern Territory before they were protected in 1971. Experimental egg harvests commenced in 1983 for C. porosus and ranching operations with CITES approval commenced in 1987. Initial management programs for crocodiles (C. porosus and C. johnstoni) in the Northern Territory included harvest of eggs, hatchlings, juveniles and adults from the wild to rear in captivity for production. The 1998 management program (PWCNT 1998) also allowed non-hatchlings to enter trade directly after harvesting, without the need to spend time in a farm. However, the poor quality of skins from wild animals means this source is rarely used. Numbers harvested increased from 17 individuals in 1997 to 158 individuals in 2001 but subsequently reduced to 65 individuals in 2007. This does not include problem crocodiles removed by NRETAS. The harvest of eggs is a critical component of the Northern Territory crocodile industry. Since farming started in the early 1980s, the total number of eggs collected has increased from 135 in 1984 to a maximum of 40,702 in 2006-07. 3. Threats and impacts Existing patterns of land use (chiefly pastoral, reserves and Indigenous lands) are generally consistent with retaining large wetland areas and their dependent crocodile populations. Groombridge (1987) and Jenkins (1987) have detailed potential threats to crocodile populations worldwide. As with all crocodilian species, most threats (direct and indirect) impacting C. porosus are anthropogenic in origin. Within the life of this program there are no perceived or likely threats to the conservation status of C. porosus in the Northern Territory and all predictions indicate that the species will continue to be abundant. The impact of climate change through changes in sea levels, rainfall patterns and probable vegetation changes is an unquantified and largely unknown impact on the Saltwater Crocodile. The public demands for more intense crocodile management in areas close to human habitation will result in the Management Program for the Saltwater Crocodile in the Northern Territory 15
localised removal of increased numbers of animals. However, real or perceived changes to public attitudes and any subsequent reduced tolerance of crocodiles will not impact on the broad-scale maintenance of a viable Northern Territory-wide population of Saltwater Crocodiles. 3.1 Natural predators The only significant predator of adult crocodiles apart from humans is other crocodiles with larger Saltwater Crocodiles eating small animals of both species. There are predators of young hatchlings such as fish (e.g. barramundi) and birds (e.g. Black-necked Stork) and other species such as Goannas can be predators of eggs. Saltwater Crocodiles are thought to be little affected by Cane Toad (Rhinella marina, formerly Bufo marinus) poisoning (van Dam et al. 2002; Letnic 2008), possibly because the species is continuously distributed from Australia to south-east Asia where other related toad species are also found. 3.2 Drought, flood and climate change Drought can have a significant but not long-lasting impact on C. porosus populations unless coupled with other factors. Heavy rainfall and subsequent flooding, particularly associated with cyclones can cause localised egg and juvenile mortality (Webb and Smith 1987). One of the major effects of climate change is an anticipated rise in sea level with conservative estimates (Hennessy et al. 2004, 2007) anticipating an increase in sea level of 50 centimetres by 2100 and a corresponding loss of coastal floodplain systems and wetland habitat. These calculations do not take into account other anticipated and compounding changes such as further saltwater intrusion or changes in hydrology and in weed and feral animal distributions and increased temperature. As temperature determines the sex of hatchlings, long-term temperature changes could also effect the population structure. The predictions of more frequent and intense dry season wildfires and severe storm events may have negative impacts on nesting vegetation, food sources and survivorship rates. However, changes may also create opportunities for crocodiles to expand their distribution. The possible impacts of climate change remain in the realm of prediction and modeling and over a time frame much longer than the life of this Management Program. As such they cannot be mitigated within this program but monitoring should be capable of detecting significant population changes through whatever cause. 3.3 Habitat loss and modification The habitats of C. porosus in the Northern Territory are generally not threatened by development although current and proposed clearing in the Daly and Katherine regions may have indirect long-term impacts. There is anecdotal evidence that Saltwater Crocodiles are affected by the invasion of freshwater wetlands by introduced plants such as Mimosa pigra including through reducing the availability of nesting habitat. Anecdotal reports indicate that the removal of Mimosa is likely to increase Magpie Geese and crocodile nesting. Since the 1970s, disturbance of floodplain habitats by feral buffalo was greatly reduced following eradication campaigns with a resultant improvement in nesting habitat. There are increasing numbers of buffalo and pig which will cause concern as these negatively impact on nesting vegetation. The increasing value of crocodile eggs is encouraging improved control of M. pigra, feral herbivores and fire by landowners to favour crocodile nesting habitat (RMCG 2008). Management Program for the Saltwater Crocodile in the Northern Territory 16
3.4 Entanglement in fishing nets Entanglement in fishing nets is known to cause crocodile deaths in Australia. Losses of C. porosus due to accidental capture and drowning in barramundi fishing nets were documented and assessed in the early 1980s (Webb et al. 1984). Since these surveys commercial fishing has been banned within a number of river systems that are important nesting habitats for C. porosus, such as the Mary, Roper and Alligator Rivers. Fishermen are not permitted to use wild crocodiles that drown in their nets. Recent internal RDPIFR reports show that crocodile mortality due to drowning in fishing nets during 2007 and 2008 was less than 30 individuals. 3.5 Disease There appear to be no significant diseases of wild crocodiles that present a major threat to the wild population. Intensive animal husbandry of any species can create conditions which lead to high mortality due to disease and this is true for crocodiles. There were significant hatchling losses in some farms due to a disease outbreak in 2006. 3.6 Harvesting – general Over the 25 years of harvesting in the Northern Territory it is clear that the harvest has been managed to deliver the primary objectives of sustainable, viable crocodile populations (Appendix 3). The harvest has not been a threat to the species. 3.6.1 Harvesting – genetic The harvest of crocodiles and crocodile eggs is widely dispersed and unlikely to have an impact on the genetic integrity of the population. 3.6.2 Harvesting - impacts on other species, habitats and ecosystems Most eggs are collected by helicopter, which has no impact on soil erosion, water bodies, watercourses, wetlands or drainage systems. The very small numbers of eggs and non- hatchling crocodiles taken, mostly by boat, mean that these operations also do not significantly adversely impact the habitat. There is no evidence or expectation that the commercial harvest is likely to have any impacts on threatened species or ecological communities of conservation significance or that it will cause disturbance or displacement to native fauna. Similarly there is no evidence as yet that commercial harvest helps introduce or disperse invasive weeds although there is a possibility that the floats of helicopters could be a vector for aquatic weeds such as Salvinia or Eichhornia. It is becoming apparent that landholders are increasingly managing land to favour crocodile nesting habitat which means efforts to reduce mimosa, pigs and buffalo, and to manage fire will favour establishing nesting vegetation. Large crocodiles take introduced herbivores such as buffalo, cattle and pigs but the overall impact on these feral populations is probably negligible. Management Program for the Saltwater Crocodile in the Northern Territory 17
4. Management practices and performance
measures
To achieve the aims and objectives of this management program, NRETAS in conjunction with
RDPIFR implements a range of management practices to control the harvest, farming and
trade of Saltwater Crocodiles in accord with the TPWC Act and the EPBC Act. Performance
indicators are provided for each management practice. The milestones and performance
measures for the life of this program are summarised in Appendix 4.
Objective 1 - To facilitate the sustainable use of Saltwater
Crocodiles
4.1 Commercial harvest and use
Restrictions on live animal harvesting
The Northern Territory Government will seek to maintain the presence of a visible crocodile
population and large iconic (generally ≥ 4.5 m) individuals through the creation of zones where
harvesting of life cycle stages other than eggs is restricted. Harvesting will be prohibited or
restricted in some areas or circumstances if necessary to maintain local or regional populations
or to maintain non-use benefits from the species. Large individuals can be removed wherever
there is a public safety or livestock concern. In general, harvesting of juvenile and adult
crocodiles will not normally be permitted:
1. In waterways where the watercourse forms the boundary between two or more properties.
2. In catchments that are heavily used by the tourism and fishing industry e.g. the Mary River
catchment downstream of the Arnhem Highway, the Adelaide River catchment
downstream of the Marrakai Crossing, the East Alligator River, and the Daly River
catchment west of Oolloo Crossing. Where low level harvest is permitted such as for
skins, farms or for safari hunting, it will be strongly regulated to ensure that tourism
interests are not damaged.
3. From sites where crocodiles are particularly significant to local Indigenous people.
Performance Indicator
Ensure all harvest permits minimise the possible negative impact on, or conflict with, tourism,
social or cultural interests.
Harvest ceiling
The harvest ceilings covering both eggs and animals that have developed through previous
management programs were based on an adaptive management approach through
implementation of a conservative harvest, monitoring the impact of that harvest and
subsequent adjustment of the harvest. The harvest ceilings were set well above what was
anticipated to be collected and well within what was considered sustainable.
The total number of C. porosus that can be taken commercially within the Northern Territory
in a financial year, or for eggs during a nesting season, within this program is shown in Table
3. There is no requirement for the Northern Territory Government to allow the full harvest
ceiling to be taken in any year.
Management Program for the Saltwater Crocodile in the Northern Territory 18Table 3: Annual ceiling for the harvesting of crocodiles and their eggs from the wild. Numbers
are set for the financial year to include the nesting season. The egg ceiling is based
on live eggs.
Stock 2009/2010 2010/2011 2011/20121 2012/2013 2013/2014
Eggs 50,000 50,000 60,000 60,000 70,000
Hatchlings 500 500 500 500 500
Juveniles 400 400 400 400 400
Adults 500 500 500 500 500
1
The egg ceiling shown in 2011, 2012, and 2013 is an indicative increment based on appropriate monitoring
results and sustainability considerations.
Egg Harvest
The use of egg numbers as the basic measurement of the egg harvest has remained
unchanged and will continue in this program. The harvest ceiling permits and egg allocation
will be based on ‘live’ eggs (see definitions). This change addresses concerns from both
industry and regulators. A practical compliance measure at an early stage in the
harvest/farming process is now the measure of eggs placed into the incubator. Royalties to
the Northern Territory Government will continue to be based on ‘viable’ eggs.
The natural mortality of eggs in the wild is usually high but varies depending on the weather
(Webb and Manolis 1993). It has been suggested that the mortality of crocodiles at each stage
of their life cycle (hatchling, juvenile and adult) is partially dependent on the density of larger
crocodiles that prey upon and competitively exclude smaller crocodiles (Webb and Manolis
1993). Because a very low percentage of eggs/hatchlings would normally survive to later age
classes in the wild (Webb and Manolis 1993) and the current harvest represents a very small
proportion of the total number of eggs laid each year (NRETAS internal data), it is unlikely that
the harvesting of crocodile eggs at current rates will substantially affect the size or age
structure of the population (Appendix 3). Continued monitoring will insure that the proposed
level of egg harvesting remains sustainable.
Currently 10 of the 12 monitored rivers are harvested. All monitored rivers have shown an
increase in both abundance and biomass (Appendix 3). This is consistent with the continued
increase in the overall population in the Northern Territory (Figure 1) and it supports
continuing with an adaptively managed increase in the egg harvest.
Recent levels of egg harvest have been approaching 40,000 eggs. It is proposed to
commence this program with an increased ceiling of 50,000 live eggs for at least the first two
years of the program.
Non-hatchling harvest
The increased focus by industry on harvesting eggs has been paralleled by a decreasing
take of non-hatchlings. The recent commercial take of adults has been less than 100 animals
each year between 2003 and 2009 which demonstrates the previous quota of 500 is in
excess of what is needed. Quotas firstly need to be demonstrably sustainable but they
should also be reflective of the needs of public safety and industry. Accordingly the ceiling of
Management Program for the Saltwater Crocodile in the Northern Territory 19You can also read
