It was the perfect setting - a warm, summer's day at one of Sydney's prettiest beaches. A huge crowd had turned out to watch our captive bred wobbegongs be released into the wild. Five, 6 year old, 1.2m sharks were fitted with accoustic tags and released into Cabbage Tree Bay Aquatic Reserve - 3 from the shore and 2 from the Sydney Aquarium boat that was anchored 100 or so metres from the shore.

Despite a record and very enthusiastic crowd, the release went without a hitch. And the immense satisfaction of releasing an animal into the wild was felt by all.

The release forms part of a research project on how well captive bred wobbegongs do in the wild and the impact of their release on wild populations. So far, based on data collected from our first release, the news is good. Of the 10 wobbegongs released in mid-2008, consistent signals are being picked up from four. Not only are the wobbys doing well in the wild, but they seem to like their new home!

Click here to see some of the images from the day.

Image courtesy of Jayne Jenkins

When buying shark fillets from your fishmonger there's no way of knowing what type of shark you're actually buying. You could be eating dusky or bronze whaler (sold at Coles supermarkets), dogfish or wobbegong. There are over 300 species of sharks; one thing that many shark species share is long life histories and low fecundity. This means that it takes a long time to reach sexual maturity, they don't reproduce very often and when they do, they have few offspring at each event.

To what age do you think a fish can live? Two, five, maybe ten years? Have you even thought about it?

Some fish have been found to live up to 150 years of age! One such species is the orange roughy. Many deep ocean dwelling fish, such as orange roughy, have long lifespans. But with the long lifespan comes slow reproduction rates. Some humans start reproducing earlier than these fish; orange roughy reach sexual maturity at around 25 - 30 years!

Tuna has to be one of the most popular fish eaten in the world. And one of the most valuable. Some individual Southern Bluefin Tuna (SBT) have commanded up to AUS $40,000 PER FISH before being onsold at various markets in Japan. This is the predominant reason why this fish is on the verge of being commercially extinct.