CONSERVATION OF GREAT WHITE SHARKS

The white sharks are classified in the kingdom Animalia from the phylum Chordata, they are of the class Chrondrichthyes from the family Camnidae and genus Carchardon. The white sharks are scientifically called Carchadon Carchardrians [1]. The great white sharks are known as the white sharks, white pointer or white death [2]. They are extremely large, body shaped like torpedo with silver to blue – grey colour and white underside with pointed snout. They have a Standard Dorsal fin (is on top of the shark), pectoral fins (bottom - front and rear) and Caudal fin (crescent shaped tail) and additional of two small pelvic fins. The fins are important because they drive and guide the sharks through the water in a streamline motion like that of an airplane. White sharks have 3 000 teeth arranged in several rows, their teeth are in the shape of a triangular and are 7.62 cm long [1].

The white sharks are more likely to be found in ocean water, deep or coastal waterways but especially Islands with high populations of Pinnipeds. Pinnipeds are defined as the marine mammals that are characterised by hair, flippers, e.g. sea lions, elephant seals etc. They can weigh up to 3175 Kg but the average weighed between 1361 to 2268 Kg and they are 3 to 4.5 m long. The white sharks feed on seals, elephant seals, sea lions, other fish, dolphins, sea turtles, otter, small toothed whales, carrion etc [1].

These types of sharks are less abundant globally than other sharks. Should there be a high fishing rate; the population of the great white sharks will be lowered because their reproduction and growth rate is slow [3]. The female white sharks can reproduce from 12 to 15 years and the male from 8-9 years. The gestation period for the great white shark is more than a year [4]. Their annual reproduction rate is 2-6 pups and this is considered as the slowest reproductive rate [5].

Minister of Environment and Heritage, Dr David Kemp of Australia indicated that the great white sharks declined by 20% over the last three generations and in some areas [6]. Australia is recognised being the world leader in the protection of the sharks. South Africa, USA, Namibia, Malta and the Maldives are also protecting the great white sharks [6].

Human have impact in the declining of the white sharks, during the mid of 1960’s the gills nest were placed in the large coast of KwaZulu Natal, South Africa. The main aim of placing the gills nest was to protect the bathers from the sharks. As a result, the white sharks and other sharks travelling along the coast are still entangled in the nest and they die of asphyxiation. Asphyxiation is a death that results from lack of supply of oxygen to the brain. However, the sport fisheries threaten the great white sharks worldwide. The sport fisheries seek the white sharks as trophies and if accidentally caught by commercial fisheries that price their fins [3]. Some other people hunt the large jaws of white shark because they can have USS 10,000 for collecting the jaws [4]. The fins of the sharks are valuable in the Asian fish market because they are used as the shark fins soup [3].

Dr. Ramón Bonfil, shark expert, WCS Conservation Fisheries Scientist, in partnership with the South African Marine and Coastal Management Branch, with collaboration of University of Pretoria, University of Cape Town and Natal Sharks Board launched a study of great white sharks. They were using a satellite tracking devices and other techniques to collect information on the movement and seasonality of the great white shark. The research started in 2002 and since 2002, they attached 43 satellite tags of which 25 tags were the pop-up archival tags (PAT Tags). The PAT tags records the environmental data surrounding the shark once every minute. The data gathered is send via satellite at a later programmed time at the end of the experiment. The remaining 18 satellite tags were attached to white sharks during their research. At the end of their study, the following will be known: specific preferred habitats of the sharks, how to design the protection measures that will guarantee the survival of the great white sharks globally [3].

The sport fisheries together with the commercial fisheries must stop fishing the great white sharks. The sharks also showed that they hunt people, in 1995, Australia launched its bit to conserve the great white shark and on the very same day one of the fisherman, David Weir was attacked and killed by a great white shark [6]. The net that is placed in the ocean to protect the bather should be of the size that will not injure the sharks because the great white sharks are also declining because of the asphyxiation. The system that is used by the Dr Ramon Bonfil and his team should be followed, as they are aiming to design the protection measures that will guarantee the survival of the great white sharks.

References

1. Anonymous. Unknown Date. Great White Shark Taxonomy & Description. [Cited 08/03/2007: 11h00]. Available from:
http://www.tigerhomes.org/animal/great-white-shark-taxonomy.cfm.

2. Wikipedia contributors. Great white shark [Internet]. Wikipedia, The Free Encyclopedia; 2007 Mar 8, 06:23 UTC [cited 2007 Mar 9]. Available from: http://en.wikipedia.org/w/index.php?title=Great_white_shark&oldid=113517316

3. Bonfil R. 2002. South Africa. Great White Shark Conservation. Marine Conversation Program. [08/03/2007; 14h00]. Available from: http://www.wcs.org/international/marine/marineafrica/gws.

4. The White Shark Trust. 2002. South Africa. [Cited 08/03/2007, 13h00]. Available from: http://www.whitesharktrust.org/pages/index.html

5. Kemp D. 2004. Australia Moves to Protect the Great White Shark. Australian government. [cited 07/03/2007, 12h00]. Available from:
http://www.prbo.org/cms/index.php?mid=215

6. Cribb J. and O’Brien N. 1995. Call to protect great white shark. The Australian [Cited 08/03/2007, 10h00]. Available from:
http://ink.news.com.au/mercury/mathguys/articles/1995/950914a1.htm.


Image credits

1.http://www.apexpredators.com/store/showCategoriesProducts.asp?categoryID=6

2. http://www.wcs.org/international/marine/marineafrica/gws

Ms Evelyn Maleka
CSIR, Research and Development Core
P.O. Box 395
Pretoria
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Tel: (012) 841 2133/2807
Fax: (012) 841 4405
Email: emaleka@csir.co.za
http://malekaevelyn.blogspot.com/

CONSERVATION OF FISHES IN SOUTH AFRICA

Many people in South Africa rely in the ocean for their food, extraction of minerals and recreation (1). This reliance by people in the marine food puts the oceans under pressures which also changes how the marine ecosystem functions (1). In South Africa unauthorized hunting of the wild animals on land is restricted compared to hunting of the marine organisms. The major threat in the marine environment in South Africa is the exploitation of the marine organisms. Many fishing industries are faced with uncertainty if the pressure in the fishing of hakes is not reduced (3). Conservation of the marine organisms needs to be done through public awareness. The ocean provides more than 200 million people with jobs around the world (2). The biodiversity of the ocean and its natural resources is not well managed which makes it unsustainable.

It is estimated that 95 million tons of fishes are caught per year in South Africa (1). The Food and Agricultural Organization (FAO) declared that nine of the sixteen major fishing zones are overfishing (1). The removal of large amount of fish in the ocean disrupts the marine ecosystem in all levels and disturbs both physical and biological environment (1). The South African government stress the sustainable catches of fish as primary objective without considering the environment and the species which are not targeted. The primary objective of catching fishes has failed all around the world because of the decrease in the number of fish. As fish depend on other organisms in the marine ecosystem to maintain its productive capability, the survival of other organisms such as algae is not taken into consideration by managers (1). This will have negative impacts if the structure of the ecology and its process which supports the production stock is affected by overfishing.

Nearly all parts of the marine environments are affected by the human activities. People who are catching fishes are now targeting fishes which are found in deep sea compared to the off-shore fishing (2). Targeting of the fishes in the deep water is attributed to the fact that, fishes in the shallow water have been depleted. Natural refuges are now becoming scarce in the coastal environment because of the improvement of technology and the access of the human beings (1). Some of the human activities, exploitation, disturbance and pollution in the ecosystem are now reduced in the Proclamation of Marine protected areas (MPAs) (1). The main function of the MPAs is to preserve the representatives of the community of the species into its natural states (1). The MPAs help in the conservation of the marine species by providing sites which are not disturbed with monitoring, education, tourism and the research.

The management of catching fishes in South Africa remain that of the single species approach which often reduces the mortality which occurs accidentally and dumping (1). The method of fishing which is used in the catching of the fishes is known as bottom-trawl which is responsible in the high number of catches and fisheries in South Africa. These trawlers operate in the area of high diversity and this result in the catches of the unwanted species. It is fortunate that nowadays trawlers are equipped with excluders which reduce catching of the fishes which have some fins (1). Other trawlers for catching fishes have small sizes of meshes as to allow small species which are catched accidentally to escape (2).


REFERENCES

1. Attwood, C. L. Moloney, C. L. Stenton-Dozey, J. Jackson, L. F. Heydorn, A. E. F. and Probyn, T. A. 2000. Marine biology. [Online]. [Cited 2007 March 05]: Available: http://www.nrf.ac.za/publications/marinerep/conserve.htm

2. Van Der Elst, R. 2002. Harvesting nature’s bounty wisely: Serial overfishing depletes species. [Online]. [Cited 2007 March 06]: Available from: http://www.scienceinafrica.co.za/2002/september/overfish.htm

3. Morris, R. 2006. Consultant warns on overfishing of hake. [Online]. [Cited 2007 March 05]: Available from: http://www.busrep.co.za/index.php?fSectionId=561&fArticleId=3444466


Peter Muvhali
CSIR PTA
0001
Tell no: 012 8142133
Fax: 012 8423676
E-mail: smuvhali@csir.co.za
URL: http://www.blogsoccer-peter.bogspot.com

THE NEED FOR A SUSTAINABLE USE OF THE MEDICINAL PLANTS IN KWAZULU-NATAL

There is a great demand for traditional medicines in Kwazulu-Natal (1). The informal sector trading of indigenous plants products for medicines and other products of the plants is in the increase. Population growth, development, unemployment, inflow of large number of immigrants in search of work and few primary health resources lead to the increase usage of the native plants products for medicine (1). The use of traditional medicine is exacerbated by many values attached to the native plants such as women who are menstruating are not allowed to collect other plants as they will lose power.

Therefore, high demand for indigenous plants products results in a high intensity of harvesting of these plants. Sustainability of indigenous plants such as Siphonochilus aethiopicus (Isiphephetho in Zulu) and Boweia volubilis that are faced with extinction need to be encouraged (1). Medicinal plants need to be sustained because of the high rate of natural habitats destruction, shrunk and modification. Urbanization and commercial agriculture are the two main cause of habitat destruction. If not sustained, medicinal plants will become extinct, which means that plants which save lives will be lost.

In both urban and rural areas of Kwazulu-Natal, native plants are greatly utilized, because of the economic importance attached to them. These indigenous plants provide people with different goods such as building materials, fuel wood, traditional medicines and wild fruits (2). The importance of native plants products together with the needs for sustainable supply of the medicinal plants need to be sustained for future generation. People earning low wages in both rural and urban areas often use traditional medicines as a primary health care. The use of these traditional medicines is dominant in the province of KwaZulu-Natal because of the highest rate of poverty in the province (2).

Factors that encourage people to use traditional medicines include: prices which are low compared to western medicines, local availability, easy access to the traditional healers which tend to save the transport cost and other diseases which western medicines cannot cure such as Hlogwana in Nothern Sotho. Hlogwana occurs when the baby is born and the skull is not fully joint. The Government of National Unity (GNU) also recognizes the importance of traditional medicines (3). Another important factor which leads to the need for the sustainable use of the medicinal plants is their contribution in the economic growth of the province of Kwazulu-Natal. It is estimated that medicinal plants generate R62 million each year in Kwazulu-Natal which lead to the creation of jobs (1). The more the money is generated, the higher will be the number of the people employed in the gathering of medicinal plants. This is because medicinal plants are no longer found in abundance near the place where traditional healers work. The money is generated through the selling of the indigenous plants products such as roots, barks and other mixture of plants materials. Many trees are stripped of their bark for medicinal purposes.

The removal of large number of the trees results in negatively impacts, both ecologically and socially (1). This means that the majority of the people will lose medicines, and healers will lose their livelihoods. Medicinal plants are harvested from savanna, grassland and forests (1). In future, the remains of the above mentioned biomes will never meet the needs of the people. The majority of the medicinal products which are sold come from the biome of forest. The population of the wild plant species are in the decrease (3).

Planting the high number of wild plant species will lead to low unsustainable use of the indigenous plants. Programmes such as public awareness and permits to the traders need to be implemented. Conservation of medicinal plants for long term need to be sustained by the land owners. The supply and demand of the indigenous plants products were highly unknown in the past. The planting and usage of the medicinal plants has been undermined by both the agricultural sectors and formal health. Good management of the medicinal plant forests will lead to the sustainable benefits on both social and ecological perspectives.


REFERENCES


1. Maender, M.; Maender, J; and Breen, C. 1996. Promoting the cultivation of
Indigenous plants for markets: experiences from Kwazulu-Natal, South Africa.
[Online]. [Cited 2007 March 02]: Available from:
http://www.fao.org/docrep/w3735e/w3735e16.htm

2. Karmann, M. and Lorbach, I. 1996. Utilization of non-timber tree products in
Dryland areas: Examples from Southern and Eastern Africa. [Online]. [Cited 2007
March 01]: Available from:
http://www.fao.org/docrep/w3735e/w3735e12.htm#TopOfPage

3. Botha, J. Witkowski, E. T. F. and Shackleton, M. C. 2004. Market profiles and trade in medicinal plants in the lowveld, South Africa. [Online]. [Cited 2007 March 02]: Available from: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=213333

Peter Muvhali
CSIR PTA
0001
Tell no: 012 8142133
Fax: 012 8423676
E-mail: smuvhali@csir.co.za
URL: http://www.blogsoccer-peter.bogspot.com