Fishing industry providing shark samples for assessments

16th April 2019

Four years ago, AFMA installed cameras on gillnet vessels targeting sharks in the south-east fishery to monitor dolphin and sea-lion interactions.

However, a consequence of doing this was that human observers were removed from these vessels.  These observers collected data on interactions with dolphins and seals but also collected lengths and vertebrae, which are used to age sharks.  These “biological” samples are used to understand the growth and the recruitment of young sharks both of which are critical in the assessment of the gummy and school shark stock.

SSIA* has now been engaged by AFMA to collect these biological samples.  Gillnet and hook vessels take a sample of sharks when directed by randomly tagging some of the sharks caught on a trip.  Each tag has a unique number and when entered into the database by SIDaC samplers each shark can be traced back to the depth, fishing method, vessel and area in which it was caught.

Vessels then deliver these tagged sharks to port samplers who measure the length of the sharks and take a vertebra from about half the sharks.  The vertebrae are cleaned, frozen and then encased in resin before being sawed in half.  A fish ageing specialist can then read growth rings in the vertebrae much like growth rings in a tree.

A very similar program to sample pink ling and blue eye trevalla has being simultaneously rolled out for the auto line sector of the fishery.

SSIA have engaged Ross Bromley, an ex-AFMA manager, to co-ordinate this work.  The project would like to thank port samplers Jeff North, Atlantis Fisheries Consulting Group , Ross Bennett, AFMA staff at Lakes Entrance, Nick and Chris Pitliangas, Kyri Toumazos, Toni Clarke, the Lakes Entrance Fisherman’s Co Operative, Heath Rogers and Bob Shaw from Mure’s Fishing.  Thanks too to the crews supplying samples: the skippers and crew of the sample vessels Cape Everard, Morrie D, Christine Claire, Candice K, Jean Bryant, Diana, Lutarna, Peter Crombie.

 

 

If you are a gillnet or hook vessel operating in the fishery and would like to be involved in the project or would like to become involved in the sampling of gummy or school sharks, or ling and blue eye trevalla please email Ross here.

* The Southern Shark Industry Alliance (SSIA) represents the interests of operators and quota owners in the gillnet, hook and trap sector of the south-east fishery.