Save Our Seas Foundation - Projects - Chondrichthyan monitoring

Field Sampling Begins

2011-11-18T15:22:03+00:00

Well after all the organizing and the hard work deploying our acoustic tracking array in SE Tasmania in November, we have finally begun field sampling. The first trip was Wednesday 11th January after a long delay due to bad weather. The good news is that the neonates are there and in good numbers, so it is full steam ahead tagging and conducting other sampling. The bad news is the weather has shut us down again, but tomorrow (15th) looks promising. Stay tuned for more updates and pictures soon - Jayson

Shark sampling and tagging progressing well

2011-11-18T15:22:03+00:00

Jayson holding a captured gummy shark After a slow start it has been a very busy and productive summer. We have been in the field for most days since mid-January and it has paid great dividends. Over 600 sharks and rays have been captured and catch rates in the shark nurseries examined. A large proportion of these sharks have been neonate school sharks (Galeorhinus galeus), which are currently categorised as overfished in southeast Australia. We have acoustically tagged 40 neonate school sharks, along with over 20 gummy sharks (Mustelus antarcticus), which are the main target of the southern shark fishery. We are hoping to wrap up tagging later this week or early next week, with the addition of a few more gummy sharks. Sharks are being tracked with both fine and large scale acoustic listening arrays, with their tags to provide data for up to 5 years. Our first data download has just been undertaken and a preliminary examination suggests that all the tagged animals are moving around the nursery area and providing lots of data. We are excited to get stuck into some more in-depth analysis soon. I look forward to telling you all about the data in the near future - Jayson

Gliders do the work for us

2011-11-18T15:22:03+00:00

Marine Glider about to be deployed carrying the mobile acoustic receiver (black object between the wings)

Problem: Our acoustically tagged sharks have been moving into a large embayment that is commercially fished and as such we can’t deploy acoustic receivers in it. Answer: Attach a small receiver to some marine gliders that move throughout this important shark habitat 24 hours/day! The first glider deployment has recently occurred and despite the mission being cut short due to problems with the glider, the mobile receiver worked well and detected a tagged shark in Storm Bay, demonstrating the method has promise. We now have 2 gliders with receivers attached and on patrol and we are very excited to see how many tagged sharks they detect! Watch this space.

Will the school sharks pup in Pittwater again this summer

2011-11-18T15:22:03+00:00

Longline sampling of Pittwater Estuary (Hobart, Tasmania, Australia) at the end of October showed a lot of sharks are around after the annual winter mass exodus, but as of yet no neonate school sharks. Our fantastic catches of neonates last year gave a hint that the depleted stocks may be recovering, but we need data for multiple years to know if it was just a unusual year. It is only November, so it may be a bit early for the females to come in to pup yet. We will be back out in December, so stay tuned.