The Depletion Of Crocodile Population Around The World Biology Essay

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There are 23 widely recognized species of crocodiles, alligators, caimans and ghairals. They are informally referred as 'crocodilians', although the term 'crocodylians' technically refers to the members of Crocodylia. Under the order of Crocodylia, there are three families: Alligatoridae, Crocodylidae and Gavialidae, and under the family Crocodylidae, all 12 crocodiles are categorized under the sub-species Crocodylinae (Hutchins et al., 2003). Crocodiles occupy terrestrial, freshwater and marine ecosystems at tropical and sub-tropical regions (Penny, 1991). The distribution of crocodiles is very wide and scattered, ranging from Africa, India and Asia to Australia, and some species are found in America (Penny, 1991; Hutchins et al., 2003).

All 23 species of crocodilians were classified as critically endangered in the International Union for Conservation of Nature (IUCN) Red List of Species 30 years ago, only seven of them are still listed as endangered or vulnerable species (Abensperg-Traun, 2009). The International Union for Conservation of Nature (IUCN) is an organization that helps the world find pragmatic solutions to environment and development changes. Under IUCN Red List of Threatened Species, 3 species of crocodiles are listed as vulnerable and 4 species are listed as critically endangered species (IUCN, 2010). The Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) is the largest multilateral agreement on species conservation and regulates international trade on animals and plants through a system of permits and certificates (Abensperg-Traun, 2009). Under the list of CITES, 11 species of crocodilian are listed as species threatened with extinction and are restricted for trading, and one species is listed as species that its trade must be controlled to prevent utilization of the crocodile that is incompatible with their survival (CITES, 2010).

There are a few reasons that lead to the depletion of crocodile population around the world, but the hunting of crocodiles for skins was a major reason for the decline of most species (Hutchins et al., 2003). The over-exploitation of crocodilians for their skins after World War II resulted in two-thirds of the species being placed into the list of threatened species of CITES (Caldicott et al., 2005). Over-harvesting by skin hunters caused the depletion of populations of many species of crocodiles around the world (Santiapillai and Silva, 2001; Platt and Thorbjarnarson, 2000; Thorbjarnarson et al., 2006; Madsen, 1996). The population of crocodiles is further declined by habitat loss and also destruction of nesting beaches and associated nursery habitats of the crocodiles (Platt and Thorbjarnarson, 2000) caused by the development of coastal areas and further endangering the populations (Thorbjarnarson et al., 2006). Competition with inland fisheries that include the reduction in the availability of food and accidental drowning of crocodiles entangled in the nets cast by fishermen is also one of the reasons to decline of the crocodile population (Santiapillai and Silva, 2001). Out of fear, most people living in the rural areas of Sri Lanka regard crocodiles as dangerous animals and would gladly have them removed from their neighborhood or killed (Santiapillai and Silva, 2001). In Zimbabwe and other countries in the African region, crocodiles are widely disliked and much feared because crocodiles appear in local mythology and folklore throughout the continent, representing the power and idea of witchcraft and evil, thus creating a sanction towards the crocodiles by having the African communities to participate in the killing of the crocodiles (McGregor, 2005).

In the context of disappearing crocodile populations and influenced by the global conservation movement, crocodiles began to be identified as an endangered species (McGregor, 2005). Since then, much effort has been put into the conservation of crocodiles around the world. Sustainable-use programs are responsible for the recovery of some species of crocodiles (Hutchins et al., 2003). In African countries, after the ban of trading of products from wild Nile crocodiles (C. niloticus), killing of crocodiles in the wild had slowly transformed into commercial ranching or crocodiles as a way of substantially meeting continued international demands for crocodile meat and skin (Bishop et al., 2009). The American crocodile (C. acutus) was listed as endangered under the US Endangered Species Act and it was added to the list of CITES as species threatened with extinction as a result of intensive hunting of crocodiles for their skins. Efforts to control commercial use of crocodile products and also conservation and management of crocodiles in the wild have been made to recover the declining population of C. acutus in the United States (Thorbjarnarson et al., 2009). In Malaysia, government bodies such as Sabah Wildlife Department have been working on crocodile management plans to protect the declining population of wild C. porosus, including the listing of the species as a protected species under the Sabah Wildlife Conservation Enactment (1997) (Sabah Wildlife Department, 2004).

The skin of crocodilians has been exploited by the leather industry for the production of luxury items such as handbags, belts and shoes (Madsen, 1996) leads to a significant population declination in many countries (McGregor, 2005; Thorbjarnarson et al., 1995). In the 1980s, the world trade of crocodile skins was close to 500,000 per year, most from the wild, while the annual trade in 1999 was about 398,000, the majority from managed wild populations and farms (Hutchins et al., 2003). The production of crocodile skin in the current market is obtained by hunting and trapping of wild animal populations and later rearing crocodiles in captivity (Madsen, 1996). In Australia and New Guinea, effective management programs take place to allow sustainable use of the saltwater crocodile (C. porosus) for its skin (Hutchins et al., 2003).

Originally, the carcass of the crocodile was considered a waste product from the skin production, and was most often fed back to the crocodiles. However, the high nutritional value and the pleasant taste of crocodilian meat were reported (Madsen, 1996). Alligator meat has been marketed for human consumption in the United States (Madsen, 1996) and the harvesting of crocodile meat have been introduced in Australia since the 1990s (Manolis et al., 1991). In Zimbabwe, crocodile tail meat and fillets have become popular among tourists and are currently being exported to other countries (Madsen, 1996). The globally expanding domestic and international trade of wild species is now a multi-billion dollar business (Roe et al., 2002), and crocodile meat production increased over the years with the increasing availability of meat with the increase of crocodile slaughtering for their skins. Statistics show that crocodile meat is exported internationally, mostly to Taiwan, Great Britain, New Zealand and the Netherlands (Cummings, 1998).

In Sabah, a single species of Crocodilian, the Estuarine crocodile, also known as the Saltwater crocodile (Crocodylus porosus) is recorded (Sabah Wildlife Department, 2004). It is the most widely distributed crocodile among the family with habitats throughout the tropical regions of Asia and Pacific, scattering from the east coast of India to Australia. C. porosus is not exclusively marine or estuarine, but most are found in mangrove areas (Hutchins et al., 2003; Penny, 1991). Whitaker (1984) conducted a study on the abundance of wild C. porosus throughout Sabah and has reported that the species was depleting significantly. Over the years, the legal protection of C. porosus since 1982 and subsequent conservation measures taken by the Sabah Wildlife Department and Kinabatangan Wildlife Sanctuary has successfully recovered the numbers of C. porosus significantly (Sabah Wildlife Department, 2004).

The crocodile industry in Sabah remains at an infant stage despite the existence of crocodile farms such as the CITES-registered Sandakan Crocodile Farm, and the only species being farmed is C. porosus. Currently, the value of crocodile husbandry is mainly on tourist attraction (Sabah Wildlife Department, 2004) and the sale of crocodile skin, as the demand for crocodile skin around the world has always been high for the manufacturing of leather goods (Madsen, 1996). The skin of C. porosus is the most prized of all crocodilian skins for fashion leather (Webb and Manolis, 1989). Among all the licensed crocodile farms in Sabah, the Sandakan Crocodile Farm is the only one to have commercial success and exports skins to Singapore, live animals to Peninsular Malaysia and meat and other products locally (Sabah Wildlife Department, 2004).

While the crocodile industry in Sabah tries to expand its business into the production and sales of crocodile meat, there are some restrictions in materializing the plans. Research on protein content of C. niloticus (Moody et al., 1981) and fatty acid profiles of crocodile species such as Caiman yacare (Caiman crocodiles yacare) (Vicente-Neto et al., 2010), C. porosus and C. johnsoni (Mitchell et al., 1995) has taken place previously, but it is still lacking of other parts of nutrient analysis (Hoffman, 2008). This study that will be conducted and focus on the analysis of the nutritional composition of the meat of Estuarine crocodile (C. porosus), which is the only species found and farmed in Sabah.

The objectives of this study are as follows:

To determine the fatty acid composition and amino acid profile of C. porosus meat.

To determine the content of vitamin B1, B2, B12 and also the mineral content in C. porosus meat.

To determine the cholesterol content of C. porosus meat.