Tracking Lilly

Where has she been?

Lilly was intercepted by a scientist and some fishermen in the middle of the Great Australian Bight, off South Australia in June 2008. They brought her up onto their vessel, mounted a satellite tag on her dorsal fin and quickly slid her back into the water. After this experience, she swam past the giant limestone cliffs of the Great Australian Bight, and the many islands that mark the Recherché Archipelago off Esperence, Western Australia. The water temperature at the surface was a warm 19 degrees in this area and she felt the warm lure of the tropical Leeuwin Current (see http://en.wikipedia.org/wiki/Leeuwin_Current) that was flowing along the Western Australian coastline. From there she swam around Cape Leeuwin and into the Indian Ocean. She went past Perth and Rottnest Island, about 260 km from shore. This was very exciting for her as there were lots of new tropical fish out there to eat and even a few swordfish and tuna to chase. From there, she remained far from shore, but followed the direction of the coastline north and into the deep blue water about 1000 km off Exmouth where the water was about 21-23 °C and up to 4 km deep. While searching for food, she dived to depths of up to 500m. Out there, Lilly saw whale sharks, turtles, tuna and other makos which were feeding on the teeming schools of fish and plankton that circled giant submarine mountains that gently rose hundreds of metres from the seafloor.

What has she been doing?

Since, being tagged, Lilly has been moving quite quickly, covering more than 6,700 km (see the map below). Check out our sensational map! When she is cruising, her speed is only about 2.5 km/hr, which is similar to that of other sharks and she has been covering about 55 km per day. The scientists think she may have used the edge of the continental shelf as a ‘guide’ to navigate toward good places to find food. After spending time in the warm tropical waters of the north, Lilly quickly swam back toward Cape Leeuwin, and back around the corner into the cooler Southern Ocean. At the moment, Lilly is approximately 80 km south-west of Denmark, Western Australia, near a submarine slope called Broke Canyon. Where will Lilly go next? That is the question that the scientists cannot wait to answer!

You can also view Lillys travels via our online tracker!

View Seaturtles online animated map!

What does she eat?

Why did Lilly leave the Great Australian Bight so quickly this winter? Maybe she felt the water slowly getting colder? Maybe she was bored of her squid and mackerel diet and wanted to go and find some other tropical treats in the Indian Ocean? When Lilly and her friends pass by the south-east of South Australia they eat arrow squids and a shiny, toothy fish called a barracouta. These fish grow to over 1 m long and make a tremendous ‘mako dinner’. Barracouta often bear scars near their heads made by the suckers of squid and these scars are also found on many of the small makos in this area. This suggests that barracouta both feed on the same food as makos and are themselves food for makos!

More on satellite tagging of ‘Lilly’

On 4/6/2008 a two metre, female shortfin mako shark named ‘Lilly’ was captured and a new ‘splash’ satellite tag was fastened to her fin. This occurred many nautical miles from shore near the edge of the continental shelf in >400 m of water. Lilly was captured using a special circle hook and was carefully brought onboard the fishing vessel using a cradle made from aluminum. The shark ‘pit crew’ held Lilly using a thick mattress while the ‘splash’ satellite tag was attached to her dorsal fin and kept oxygen-rich seawater flowing across her gills using a hose. Within less than five minutes ‘Lilly’ was swimming away from the boat sporting her shiny new tag. Once Lilly was released, the scientists started using the ARGOS satellite tracking system to follow her movements.

What if I catch a satellite tagged shark?

If you capture a shortfin mako, blue shark or bronze whaler with a satellite tag attached to its dorsal fin (see pictures for examples) please retain the tag and animal (if possible) and contact SARDI Aquatic Sciences in South Australia on + 61 0882075400 or +61 0882075487.
Some of these tags record additional water temperature and dive data which can only be retrieved if the tag is returned. There is no penalty, but rewards of hats, shirts and sunglasses will be given out.