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Jewfish - Spawning & Migratory Patterns


Mondo Rock

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Hi Raiders

I tried to ask this question in another post but I thought it deserved to be its own topic (well, we'll see I suppose once the number of responses are in).

Does anyone know the spawning/migratory patterns of jewies?

For example, big barramundi tend to follow distinct patterns throughout the year i.e. spawn at estuary mouths during the build-up to the wet, disappear into the floodplains during the wet, congregate back in the upstream reaches of the rivers just as the dry season starts (to ambush all the food scurrying back to deeper water) and then disburse everywhere during the dry whilst they wait to head back to the estaury mouths so the cycle can begin again.

Do big jewies have similarly predictable habits? If so, then what do you reckon they'd be up to at this time of year?

Mondo

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Mondo,

Matthew Taylor from the uni of NSW is doing a study on just that.

He is a member here but havnt seen for a while. He did offer to give us anyone interested the tracking info as he found it, as a group of jewies were being tracked electronically to follow their habitual cycle.

If your out there Matt whats happening ? :thumbup:

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Thanks Grantm and the Dredded Eel.

Would love to see/hear the results of Mathhew Taylor's study, esp if it can help predict where Jewies will be at any particular time of the year. Also - thanks to TDE for sharing his knowledge on the topic.

Will let all Raiders know if I can find out anything else.

Mondo

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Hi one and all-

sorry i've been off the radar for so long, things have been pretty hectic :wacko: . I am just about to update our FAMER website, however i have attached the speel from the new tracking page and a habitat map we created. Yes, the long promised tracking information is finally here. I have the project being reviewed for publication at the moment, but when it is published i will be sure to make it available on the website for those who want the complete story with all its scientific nuance.

Tracking_Map1.pdf

If you dont have a GPS, the tributary at the top right hand corner is salt pan (NOT little salt pan, which is the next embayment along the Northern Bank). I have also mapped bathymetry data for the Richmond, Tweed, Hastings, Manning and Georges River, however haven't worked up the data into a map yet.

The spawning behavior of mulloway in NSW remains largely unknown. The_Dredded_Eel gives a good description of what we think happens, however at the moment there is no data to say whether or not this is fact. My views are similar, except that spawning takes place at the mouths of estuaries, with larvae transported up the estuary, rather than juveniles actively swimming to the lower salinity areas of the estuary. Either one of us could be right, but too my knowledge the

Hi one and all-

sorry i've been off the radar for so long, things have been pretty hectic :wacko: . I am just about to update our FAMER website, however i have attached the speel from the new tracking page and a habitat map we created. Yes, the long promised tracking information is finally here. I have the project being reviewed for publication at the moment, but when it is published i will be sure to make it available on the website for those who want the complete story with all its scientific nuance.

If you dont have a GPS, the tributary at the top right hand corner is salt pan (NOT little salt pan, which is the next embayment along the Northern Bank). I have also mapped bathymetry data for the Richmond, Tweed, Hastings, Manning and Georges River, however haven't worked up the data into a map yet.

The spawning behavior of mulloway in NSW remains largely unknown. The_Dredded_Eel gives a good description of what we think happens, however at the moment there is no data to say whether or not this is fact. My views are similar, except that spawning takes place at the mouths of estuaries, with larvae transported up the estuary, rather than juveniles actively swimming to the lower salinity areas of the estuary. Either one of us could be right, but too my knowledge there is no reliable scientifc information out there to say which one??!! Spawning time is GENERALLY between November and March.

Never fear, we have noted this gap in mulloway knowledge, and I am just about to commence a 4 year experiment to get a solid indication of what is going on.

I am going to retrive the listening posts from the mouth of the river in December, so hopefully will have some real answers about seasonal migration soon. These have stored data which should reveal when fish leave the estuary, and how many come back.

Anyway, hope the map is useful, if you are shore fishing go on the south bank, as it is much less crowded.....

Cheers :beersmile:,

Matt

Tracking_Map1.pdf

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Useful? Matt, that info is priceless!!!

The bathymetric data of the Georges river is awesome - looks to me like there's a big jewie holding hole just behind the headland at Sylvania, but then I may be reading the map wrong since all my other maps of the Georges don't indicate deep water there at all. Will definitely be worth exploring further as I really don't know the area very well.

Also the stuff about big Jews holding during the day but then exploring at night is great, and explains much about the techniques I've seen Greg Joyce employ whilst chasing them during the daylight hours.

Can I just say - Matt - you have a very interesting job.

Thanks HEAPS.

Mondo

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I spoke to Matt this arvo and he will be giving us a new map in the near future with land marks so we can track these holes down and catch a few big ones.

Matt giving us this info will help us improve our strike rate on the jews, what would really help him is if you keep a jewie dont throw away the head and the guts these are great for Matts research just put them in a bag in the freezer and he will pick them up, If your a C&R fisher trim off the annal fin this is also great for research

The old scratch my back ill scratch yours rule applies :1prop:

I cant wait for the new maps :yahoo:

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Sharky - i got your jewels out yesterday arvo, i will pass them on next time i drop around.......

I think the map should have landmarks, unfortunately Mondo, the map is an upriver region between the Moons and Sandy Point, but the updated map should indicate this. To access the shorebased spot on the Southern shore, i think you may have to go along the 4wd/bike tracks at "White Rock"/Menai to get there.

Should have the new map posted on Friday-

I should also give a big plug for the Recreational Saltwater Fishing License and Recreational Saltwater Fishing Trust, as they are the ones who saw the potential of our research plan and funded this project. The continued support of anglers for the license and trust should see more of these sort of projects completed in the future.

Cheers,

Matt

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