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The Grey Nurse shark (Carcharias
taurus) is one of Australia's most endangered marine species,
despite not being a threat to man. It was hunted almost to extinction during
the 1960's due to its fierce appearance and today, activities such as fishing and
diving continue to impact on the sharks.
It is estimated that there are less
than 500 Grey Nurse sharks left along Australia's east coast. Research has
indicated that without extra protection, the species could be extinct within 40
years. As such, the Grey Nurse shark is listed as endangered under the Nature
Conservation Act 1992. There are heavy penalties for harming, possessing,
buying or selling them, or for harming their habitat and special rules apply
for fishing and diving in critical habitat sites.
What do Grey Nurse Sharks Look Like?
Grey nurse sharks have large, stout
bodies tapered at both ends, a pointed snout and small eyes. Their mouth contains
long, slender, spear-shaped teeth with one small point on either side. They
have two large top (dorsal) fins of similar size and their tail (caudal) fin is
distinctive with the top lobe being larger than the bottom.
The upper surface of grey nurse
sharks is bronze coloured and the underside is paler. Juveniles often have dark
spots on the lower half of the body and the caudal fin. These spots fade as the
shark becomes larger, but are sometimes still seen on adults. Grey nurse sharks
can grow to at least 3.2 m in length.
Where do
Grey Nurse Sharks Live?
Grey nurse sharks are found mainly
in inshore coastal waters. Key habitat sites lie along the coast of NSW and southern Queensland where grey nurse sharks are
regularly found in groups. These sites generally have sandy-bottomed gutters or
rocky caves and are in the vicinity of inshore rocky reefs or islands.
There are four Grey Nurse Shark Protection
Areas in Queensland, very close to Brisbane that were declared on 19
December 2003.
These are within a 1.2 kilometre radius of the following sites:
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Wolf
Rock (off Double Island Point in the proposed Great Sandy Marine Park, Northern Section) is the most
important grey nurse shark area in Queensland. It is a mating site and has a high
number of female and pregnant sharks.
- Flat
Rock (off North Stradbroke Island, Moreton Bay Marine Park)
- Cherub's
Cave (Moreton Bay Marine Park)
- Henderson Rock (Moreton Bay Marine Park).
What do Grey Nurse Sharks Eat?
Grey nurse sharks are active mainly
at night and feed on a wide range of bony fishes, sharks, rays, squids and
crustaceans.
How do Grey Nurse Sharks Breed?
Sexual maturity is reached in about
4-6 years for males and 6-8 years for females Males can reach a length of 1.9 metres
and females can grow to 2.2 metres in length. It is believed that mating occurs
in autumn. Towards the end of a 9-12 month gestation period, the most advanced shark
embryos eat the remaining developing embryos, then the unfertilised eggs within
the female shark's uterus. Females then enter a resting stage for around one
year. With the birth of only one or two pups per litter (i.e. one or less every
two tears), the grey nurse shark has the lowest reproductive rate of any shark
and population recovery from low numbers is severely hampered.
Why are
Grey nurse sharks threatened?
Illegal fishing and injury due to
accidental capture by commercial and recreational fishers poses a threat as
does capture in beach safety (shark) mesh nets.
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Brisbane Shopping
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The new DFO at Jindalee opened 16 November 2007. There are many outlets at Jindalee's DFO. Here is a list to help you find what you need (and want).
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Fun Stuff
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When looking to dine out in Brisbane, it is helpful to understand the different
precincts for
restaurants in Brisbane.
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