(Aus)Shark catch sparks warning

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Shark catch sparks warning

Tasmania

http://themercury.com.au/0,3546,1437716%255E3462,00.html

By STEVEN DALLY

21nov00

 

CSIRO biologists have warned Tasmanian fishermen that by law white pointer

sharks must be released if they are found alive.

 

The message comes after four Hobart fishermen yesterday captured a protected

white pointer, almost three metres long, off Variety Bay on Bruny Island's

east coast.

The shark, after initially appearing dead, showed signs of life – ironically

while being lifted from the water by a Marine Police vessel – but later

died.

 

The shark, a male estimated to be about six years old, was towed to Hobart

and handed over to CSIRO scientists for study.

 

Hobart amateur fisherman Michael Grimwood, on a three-day fishing trip with

mates on his motor cruiser, had risen early yesterday to check their nets

and cray pots.

 

Mr Grimwood said one net had been hard to get to the surface.

 

" We thought we must have been tangled in the kelp or something, " he said.

 

" Then we got this big fin up to the side of the dinghy. "

 

" The tail came out and we thought it was a big bluefin tuna or something

because we couldn't see the head until we got it back to the big boat. "

 

The shark, which had deep mesh wounds, had to be cut out of the net.

 

It was later identified by a Marine Police patrol crew which winched the

shark out of the water on its gantry.

 

" It was all tied up and kicked around for a while, " Mr Grimwood said.

 

" It was quite safe then because it was tied to the police boat.

 

" It was very sick. If it was full of beans when we first caught it we would

have let it go. "

 

CSIRO shark biologist John Stevens said that laws around Australia protected

white pointer sharks.

 

" If a white shark is caught by a fisher, whether professional or

recreational, and the shark is still alive all reasonable steps should be

taken to let it go alive, " he said.

 

Fellow CSIRO shark biologist Barry Bruce said relatively few male white

sharks were caught.

 

Only two or three were caught in nets around Tasmania each year.

 

" Although sad to see an animal meet its end like this, what we like to do is

make sure it is not wasted from a scientific point, " he said.

 

" We will be taking tissue samples for a worldwide genetic study to have a

look at populations and differences in white sharks around the world.

 

" (We will be) looking at its reproductive state and taking vertebrae from

below the dorsal fin so we can try to age it. "

 

Mr Bruce said there were no reasonable estimates for any white shark

populations, but they were not as common in Tasmanian waters as in other

southern Australian areas.

 

" These sort of sharks reproduce extremely slowly, " he said.

 

" Females don't start reproducing until they are 4.5 to five metres in length

and then probably only every three years. "

 

" Natural mortality probably equals the natural birth rate and because

pupping doesn't happen all that often even incidental captures can severely

affect a population and it can take them decades to recover. "

 

 

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