A tagging program for southern bluefin tuna is looking at
the survival rate of the fish after they’re caught and then released by recreational
fishers.
Dr. Sean Tracey, from the University of Tasmania’s Institute
for Marine and Antarctic Studies, is leading the study and says
state-of-the-art satellite tags are being used in one of the largest tagging
studies of its kind.
He says so far the tuna have shown they are pretty
resilient.
“It is early days but there are indications that they’re a
fairly hardy species.
“We had one fish actually re-caught off the New South Wales
coast about five days after we tagged it, so they’re obviously going back to
feeding, and we’ve also had some fish that have had a bit of hook damage and
those fish are still swimming around.â€
However, Dr. Tracey says some of the tuna aren’t so lucky.
“We’ve had one or two fish that have been eaten by a shark
and we can tell that by the temperature. It goes up significantly when the tag
is in the shark’s gut and also it goes dark because the tags record light.
“So you can see that it goes dark for a few days and then
the shark has obviously regurgitated the tag and it sends all that information
back to us.â€