Mangrove jack research in NSW

[Leaping bonito]

Hello AusFishers
MANGROVE JACK RESEARCH IN NEW SOUTH WALES
I’m posting this to ask for some help from members of this site who target mangrove jack in NSW.
I have started a PhD project through Southern Cross University on the biology and movements of mangrove jack in NSW waters. The research is funded by the Recreational Saltwater Trust.
Jacks have been studied fairly thoroughly in far north Queensland, up around Cairns and Townsville, but it’s not known whether their biology and life cycle differ towards the southern limits of their distribution. In particular, it appears that at least some large adult jacks might remain in NSW estuaries more or less permanently, rather than moving out to offshore reefs as is the case up north.
In order to better understand this, and other aspects of the life cycle of NSW jacks, I am going to need some jack frames, and this is where I am asking for your help. If you catch a jack in NSW and decide to keep it, I would really appreciate it if I could have the frame. I will collect any frames from a location convenient to you.
I know many keen jack fishers practice a lot of catch and release, and I’m not asking anyone to kill a fish they would otherwise wish to release. However, if you do decide to keep a couple, each and every frame will provide valuable information to help understand the biology of jacks at the southern limits of their distribution.
Frames will be dissected to get the otoliths (ear bones), as well as the reproductive organs and stomach contents. These samples will provide important insights into the age, growth, reproduction and feeding habits of the species.
If you would like to donate a frame, please put it in a plastic bag (any ordinary plastic bag is fine) and make a note of the date you caught it and the capture location (this will be kept strictly confidential). With regard to capture locations, a latitude and longitude is best, but general location names (for instance, the name of the river in which you caught the fish) are also fine.
When you’ve bagged the frame, keep it as cold as possible (to ensure the guts don’t break down too much). Frames can also be frozen while awaiting collection. Then give me a call and I will meet you to collect the frames. You will go into a draw to win some prizes that will be given out towards the end of the project.
Thank you for reading this post, and for any help you may be able to give me. If you would like some further information on the project, please feel free to give me a call or send me an email.
Cheers,
Toby
Phone number: 0439796609
Email: mangrovejackresearch@gmail.com

[Leaping bonito]

Hello Ausfishers

Apologies for bumping an old thread. However, with summer now here, I just wanted to remind forum members of my research on mangrove jack is NSW, and ask that if you keep a jack in NSW, could you please keep the frame for me? Every frame will provide valuable data for my research. If you are able to donate a frame, all you have to do is put it in a plastic bag, keep it cold (freezing is fine) and contact me. I will collect the frame from you. My phone numbers are 0439796609 or (02) 6648 3900. A few frames have started coming already, mainly from the spearos with a couple from line fishers. Thank you for reading this, and good luck with the jacks!

Cheers,

Toby

[crab man]

ill note your numbers toby but wanted to know will you release your research finding here on aus fish ?

[Leaping bonito]

G'day Crab Man, thanks for noting my numbers down.

Yes, I will post my findings up on AusFish. It's a three year project, which is funded by the NSW Recreational Saltwater Trust (i.e. fishing licence money). At the end of the project, I will write up all of my findings, and they will be supplied to the Rec Trust and will be publicly available through the trust as well. The final report will be quite long, but I will definitely post up the most important findings and major points on AusFish (and the other forums where I have asked for help from fishos). Best of luck with the jacks this summer.

Cheers,

Toby

[wayno60]

ok well alot of us are in QLD, and home for me is the gold coast. where abouts are you?
Also will it be like the 285 page one the DPI did in QLD.

cheers

[Leaping bonito]

Thanks Wayno60. Yes, I thought AusFish was mainly a Qld-based forum. I'm based in Coffs Harbour, and my research really is focussed on jacks in NSW. Basically, I put the post up to attract the attention of AusFishers who might fish the Tweed and other systems in the far north of NSW. Having said that, if you do keep any jacks from just over on the Qld side of the border, I'm still interested (as jacks obviously don't respect state borders!). However, any further north than that is starting to get too far out of my study area. For example, I'm definitely not going as far north as the Sunshine Coast, as I will just end up spreading my resources too thinly.

There will be some differences between my project and the big Qld Fisheries study which was done a while back. First, I should be clear that my project won't be as big. The Qld research was quite a major project, and I believe had several scientists working on it. In contrast, my research is for my PhD project, and as such I will be doing most of the work on it myself (with help from my supervisors).

Also, my research will look at some slightly different areas of jack biology compared with the Qld study. In particular, I'm going to use acoustic telemetry (small sonic tags implanted in the fish) to track jack movements. This should provide some interesting and detailed info on how jacks move around within estuaries, and between estuaries and reefs.

I'm also going to be studying the jacks' diet, which wasn't part of the Qld study. On the other hand, the Queensland scientists were able to assess age and growth in more detail than I will be able to, as they were able to obtain reasonably large numbers of jacks from commercial catches (from the reef line fishery up in north Qld).

The other parts of my project will involve using otoliths (ear bones from the fish frames) to assess fish age, and reproductive organs (also from the fish frames) to determine spawning seasons and size at maturity.

So, while my project and the Qld one have similar aims (apart from our very different study areas), there are a few areas of difference. While my project won't be as big as the Qld research, it will still provide insights into the basic biology of jacks, which have never been studied at the southern end of their range (the north Qld study sites were over 1500 km north of my study area, and there do seem to be some differences).

Apologies for the lengthy reply, but I just wanted to give some detail about what I'm trying to do, since I am asking fishos to be kind enough to donate some frames. Feel free to contact me at any time if you'd like any more info.

Cheers,

Toby

[Leaping bonito]

Hello Ausfishers

Here are some photos of the first three jacks caught for acoustic tagging in my research. These fish will soon be swimming around providing data on jack movements in northern NSW.
IMG_4412[1].jpg
IMG_4394[1].jpgIMG_4395[1].jpgIMG_4396[1].jpg

[Leighton]

Is there any valuable information I/we can collect for you from a Jack caught in NSW but released?

[wayno60]

so being acoustic tagged can you tell that from the out side of the fish?? hate for one to be caught then all of a sudden you see it traveling up the highway...miles from the water.

[Si]

Thats good research mate. Would be interesting to find out what they do between day and night, tidal stages, seasons. Hopefully your tags can last awhile and give you that info. my mate did that for the eastern cod and got some interesting data.

[Leaping bonito]

G'day All

Thank you for your interest in the jack research. Wayno60, my tagged jacks will also have a normal, external tag in their shoulders (just the usual plastic 'spaghetti' tag). It will be yellow, and the words on it will be 'Transmitter inside Ph: (02) 6648 3900'. The tags will also have a number on them between 100 - 199. You're absolutely right in that the acoustic tag is completely internal, so if the fish only had that, there would be no way to recognise a tagged fish.

Leighton, thank you for the offer of providing info from your released catches (by the way, that's a beautiful jack in your avatar). All of you jack fishos out there are a very valuable resourse in this sort of work (especially for fish like jacks, which are challening to catch). I'm going to have a good think about the kind of info you could provide (only those who are willing of course) and will get back to you soon.

Si, my tags will last about two years, so should be able to collect plenty of info on jack movements.

I'll update this post soon, and in the meantime here is another jack which I caught for tagging last night, along with a couple of by-catch estuary cod.

IMG_4418[1].jpgIMG_4413[1].jpgIMG_4416[1].jpg

[Leaping bonito]

Hello Ausfishers

Four jacks have now been implanted with acoustic tags, and will be released back into the wild over the next few weeks. So far, they seem to be recovering well from the operation. I will post updates as things progress.

Here are pics of another two jacks caught for tagging over the last couple of days.

Cheers,

Toby
IMG_7733.jpgIMG_7752.jpg

[nigelr]

Great stuff Toby!

[Leaping bonito]

Thanks Nigelr

It's been a while since I posted an update on the jack research on Ausfish. The Christmas and New Year period was busy, with some good hot weather and warm water for jack fishing. I now have twelve fish with acoustic tags. Two of these fish were very kindly given to me by a local jack fisho - a really great boost for my research.

I've also been preparing some acoustic receivers, and these will be in the water very soon, in time for the release of my first group of tagged fish.

The frames have also been coming in well, so thank you to all who have given a frame so far. Every frame is very valuable to my research, and will be put to good use, so if you keep a jack in NSW, I'd really appreciate it if you could keep the frame and give me a call.

I've also attached a pic of a beautiful juvenile Queensland groper which I caught while jack fishing. Obviously not what I'm after, but a beautiful fish and a good surprise.

Will post more news as it comes up,

Cheers,

Toby

IMG_7760.jpg


IMG_7765.jpgIMG_7794.jpgIMG_7795.jpgQld Groper 007 (2).jpgQld Groper 009 (2).jpgQld Groper 010 (2).jpg

[fishboy018]

Right well that has burst my bubble nicely. I am entering my final year of a Bachelor of Marine Science and have just spent weeks dreaming up a research project for my honours/phd that is almost identical to the one outlined above. As far as I was aware nobody else had thought of it. It is so hard to find original research these days. Had the exact same plans with the otoliths and tagging and was speaking to my professor about it just the other day. Bugger. Looks like I will have to think up something else. At least someone is doing the research and the findings will prove interesting I am sure. Good Luck with it Toby.