Grey Nurse Sharks - Nick Otway (NSW Department of Primary Industries)

Anth is in the studio today, with Pete keeping him company, and Mel deftly manipulating the panel, keeping all things audial and technical in order.

The largest toxic algal bloom EVER has been discovered off Washington State, USA (30 by 15 miles big). It's stuck in an eddy at present, which explains its size and concentration. So if you happen to be flying over that part of the ocean in the next couple of weeks (as you do), and happen to see a big yellow smear on the ocean surface, that's what it is. Scientists as yet are not sure whether the bloom is toxic.

Nick Otway joins us from the NSW Department of Primary Industries (senior research scientist) to chat to us about his research of Grey Nurse Sharks along Australia's east coast. In all, he estimates there are about 500 left in the wild at present.

Once very common in our waters, they tend to congregate in particular gutters, with up to fifty in each. Recent surveys have showed that up to 60% percent of these gutters no longer have sharks present in them.

The decline is partly due to overfishing (largely spearfishing), which combined with their reproductive strategy (intra-uterine cannibalism - effective, but slow) has led to their decline over the past few decades.An unprovoked attack has never been recorded along the east coast of Australia.\

In the future Nick aims to use a new type of acoustic tag that allows them to follow the movement of sharks live on computer no matter where they are. We look forward to catching up with Nick to see how this work goes.

Physical Phenomena

The deepest spot - Challenger deep in the Marianis Trench is 35,813 ft or 10,915 m deep. You could put Mt Everest into it, and the top would still be a mile underwater !!. The water pressure at the bottom is about 7.3 tons per square inch and there is life down there.

The tallest wave - 1,720 ft, 524 m or about 140 stories (the World Trade Centre was 101 stories). It was ar Lituya Bay, Alaska on July 9th, 1958.

The largest ocean - the Pacific - covering a third of the earths surface.

Animal Facts

Noisest animal - the blue whale - generating 188 decibels - detected 850 km away

Stongest bite - measured using the good ol' Snodgrass gnathodynamometer was from a 2 m long dusky shark. It generated 19.6 Tons/square inch - almost 3 times the pressure at the bottom of the Marinanis trench.

The largest eye - The Atlantic Giant squid - 400 mm across

Slowest growth - a deep sea clam that takes 100 years to grow to 8mm

Biggest animal - Blue whale at around 33 m and 190 tons in weight

Fastest Dolphin - Killer whale at 56 km/hr, with the common dolphin clocked at 60km riding bow waves

Deepest sea star - Eremicaster tenebrarius - taken from 25,000 ft or 7,600 m

Deepest sea urchin - unidentified - taken from 23,700 ft or 7,250m off Indonesia in 1951

Heaviest Crustanean - Atlantic Lobster - 42lb 7oz, caught in 1934 and named Mike (not sure if that was by the fisherman or other lobsters)

Largest Gastropod - Trumpet or Baler conch - found off Australia in 1979 was 40lb (18kg) and a metre in girth.

Man and Marine

Transatlantic Crossing - Cat-Link V, in July 1998 took 2d, 20hr and 9 min (average speed on 41.3 knots). Compare that to the Siris that took the record on 22 April 1839, in a time of 18d 14h 22m at an average speed of 8 knots.

Fastest solar powered pacific crossing - Japan's Kenichi Horie took 148 days in 1996 in a solar powered boat.

Tallest hand made sand castle - 7.3 m in Illinois, USA on Sept 1998

Longest hand made sandcastle - 10.4 km, Long Beach, Washington, 1990

24-h water cycling record - 104.6 miles (over 160 km)

Driving across the English Channel - 1hr 40 m and 6s - set by Richard Branson in June this year.

"Eleven"

"Prodigal Daughter"

" Invisible, Indivisible"

Lisa Miller

Eddi Reader

Kavisha Mazella

Brett joins us, in honour of the first stunning Sunday this side of winter, to give us the goss on all areas wet and salty. Water is lovely, around 15 degrees and getting warmer with each and every day. With the warmth, the fish seem to grow in numbers, the big schools of Pilchards are starting to appear in the bay, even schools of Yellow-tail Kingfish have been reported down toward Geelong.

The Cuttles are in the mood for mating, the males have some spectacular colours which can be seen at present down toward Portsea. The same goes for Squid at present. These animals are real characters underwater - their capacity to move quickly, change their colour and even the body texture, makes them very interesting to follow around.

In a word, Spring is well and truly here, and with it all manner of animals (be they legged, finned, tentacled or pinnipeded) have come out from their winter retreats. If Brett were to pick three dive sites, they would be:

Lawrence Rocks (off Portland, Western Victoria)

Lonsdale Wall (Port Phillip Heads)

Gabo (Victoria/NSW border).