CONSERVATION:
Many species of crocodilians are falsely viewed as man-eaters, but fear of this species is not unfounded, with a number of people injured or killed each year, although in most cases these tragedies can be avoided with increased awareness. However, loss of life has led to a degree of antipathy towards the species, making conservation measures more difficult to implement.
Given its relatively wide distribution, control of trade has historically been difficult until recent years. The commercial value of the hide is very high (the most valuable of any crocodile species), due to the lack of ventral osteoderms which otherwise make tanning difficult, and the size and shape of the belly scales. Unregulated hunting mainly between 1945 and 1970 caused a dramatic decline throughout the range of the species. This has been controlled in some areas, notably Australia, but threats from habitat destruction still exist. Protection in some countries is often ineffective, and while illegal trade is relatively insignificant now for this species, killing due to fear is becoming an increasing problem.
Australia has been the centre for most of the extensive research carried out on this species, and several model breeding and conservation programs exist there. It is estimated that there are at least 100,000 to 150,000 crocodiles in the northern three states of Australia (Western Australia, Queensland and Northern Territory where the largest population base exists), so the problem has now shifted to one of persuading landowners and public alike of the value of the species which is otherwise only seen as destructive. Sustainable use programs have been implemented in the Northern Territory, and have proven to be highly successful in giving people an incentive to preserve not only the crocodiles but more importantly the habitat which supports them. These primarily involve collection of eggs from wild nests, with payment for the eggs being given to the landowners. The hatchlings are then sold to crocodile farms for raising and skin production. Extensive surveys are conducted with the harvesting, which has demonstrated no detectable impact of the harvesting program on population growth. A trial harvest of wild, adult crocodiles involving aboriginal communities was started in 1997 - the first time crocodiles had been legally hunted in the Northern Territory for 26 years. Some discussion of safari-style hunting is now taking place, directed by traditional Aboriginal landowners, but such programs are yet to be implemented.
Although populations are recovering in some areas, others are less positive. Habitat destruction and illegal hunting can be major problems (e.g. Irian Jaya). The population in Sri Lanka is in grave danger of extirpation due to local fears and attitudes, linked with habitat removal. Feral buffalo populations in Australia were responsible for destroying a lot of nesting habitat in the Northern Territory in the 1970s and 1980s, although feral eradication programs have reduced this problem considerably. Restocking programs in India (Bhitarkanika National Park in Orissa) have met with success, showing potential for other areas, although these need to be found. A sustainable use program established in Papua New Guinea has set the standard for similar projects in this and other species of crocodilian. These are based upon both wild cropping and ranching schemes. Farming in other areas (particularly Australia) is now performed on a large scale. Despite this, basic survey information is still lacking in other parts of this species' range (e.g. Indonesia).
The future of the species seems to be very secure at the moment, given the large population bases in Australia and Papau New Guinea. However, it is likely that the range of the species will be severely reduced through extirpation of many small populations in various countries unless management programs can be implemented, or more effective control and protection set up. The idea of sustainable use remains controversial, yet it is has been clearly demonstrated to be effective in the conservation of this species. The only areas where the species is likely to disappear are those where proper management and conservation programs do not sufficiently protect the wild populations.
MORE INFORMATION:
For more information on distribution and conservation issues for this species,see the CSG Action Plan resource.
SIGNIFICANT REFERENCES:
Messel, H, & Vorlicek, GC (1989). Ecology of Crocodylus porosus in northern Australia. In: Crocodiles. Their Ecology, Management and Conservation. A Special Publication of the IUCN/SSC Crocodile Specialist Group. IUCN, Gland, Switzerland. pp. 163-184
Ortega, G, & Regoniel, P (1993). Conservation, management and farming of crocodiles in the Philippines. CFI News 6(1): 4-11
Solmu, GC (1994). Status of Crocodylus porosus and Crocodylus novaeguineae population in Papau New Guinea, 1981-1994. In: Crocodiles. Proceedings of the 12th Working Meeting of the Crocodile Specialist Group. IUCN, Gland, Switzerland. pp. 77-102
Webb, GJW, Manolis, SC & Ottley, B (1994). Crocodile management and research in the Northern Territory: 1992-94. In: Crocodiles. Proceedings of the 12th Working Meeting of the Crocodile Specialist Group. IUCN, Gland, Switzerland. pp. 167-180
Webb, GJW, Hollis, GJ & Manolis, SC (1991). Feeding, growth, and food conversion rates of wild juvenile saltwater crocodiles (Crocodylus porosus). J. Herpetology 25(4): 462-473
Webb, GJW & Manolis, SC (1989). Crocodiles of Australia. Reed Books Pty. Ltd., NSW, Australia. pp. 160
Webb, GJW & Messel, H (1978). Morphometric analysis of Crocodylus porosus from the North Coast of Arnhem Land, Northern Australia. Aust. J. Zool. 26: 1-27
Webb, GJW, Sack, GS, Buckworth, R & Manolis, SC (1983). An examination of Crocodylus porosus nests in two northern Australian freshwater swamps, with an analysis of embryo egg mortality. Aust. Wildl. Res. 10: 571-605