Science and Study Tools
Dissolved Oxygen

Pete Mate,
If you want to get all scientific and go super deep into the world of water in lakes and the properties of sea water then a DO probe will give you many new clues and much more information into the changing chemistry of the water in which the fish and other animals live.
DO Probe means -Dissolved Oxygen, but testing temperature, conductivity, ph, salinity and so on are part of the capabilities of some of these units. There are many biology web sites that share information on this tool. The prices are up there making them almost a luxury item, but for what they tell you, they are cheap as chips.

Next Line- Do you really need one and will it be beneficial?
They open up a whole new world into the depths of the abyss and in truth it highly helps us understand how and why fish behave like they do in many instances and it helps give insight into whether or not a section of sampled water holds the qualities that can be required for target species to exist and function efficiently.
But in true terms it is not a tool that we can deploy to guarantee that the best fish or best fishing will be found. Driving around all day and constantly sampling water will not help find that honey pot where all the ‘gigantors’ of the fish world will be holding, but it can be used as a dip tool to guide is the right direction or to monitor changes that occur during weather adjustments or seasonal alterations.

Visual clues from sounder displayed images, and detailed clues from paying attention, such as- water colour, its circulating free flowing state or at times the lack of flow can show us signs of water that may not be up to scratch or up to standard. The noted lack of life or suspended particles or floating vegetation are all signs that can set us up to thinking that something is not right with a piece of water and it may be time for anglers to "move on".
A DO probe may show you the results of the less favourable visual signs, but it won't help the average angler on the day to increase their chances by too much.
I feel the DO probe is a tool that is essential if anyone wishes to understand a waterway in much greater depth. A tool of interest yes, one of necessity, I think NO!
I think a DO probe is a tool that would best slip into the hands of an angler once they have increased their skill levels in the many other fields related to fishing.
On the other hand, I think a temp probe for testing water temp at various depths would fix a lot of the misguided 'old wives tales' on fish and water temp tolerance.
DO Probes, Temp Data Logging Devices, and a simple temp probe on 80ft of cable broadened my knowledge on salt and freshwater bodies over the last 5 or so years. It helps us understand nature a whole lot more and as a side effect, it helps us learn a great deal more about fish.
But, just how far do we really need to go to enjoy the outdoors and fishing?
It is all out there for the taking if anyone wants it take the plunge.
We never stop learning, but often many things we learn don't help us catch more fish, but some tiny pieces of the puzzle do open many doors.
Best Regards,
Johnny Mitchell 

Tagging and Sampling

Survey sampling, tagging, follow up net sampling, electro fishing and so on has been conducted in Awoonga since day dot. Over the last 12 years we have tagged and recaptured truck loads of barra, whether on lure or in large scale sampling activities. Growth rates and survival rates were of most interest and much data has been collected since the original stockings. History in tag returns shows tags and barra that dodge anglers for years on end, to those that last less than about a week. We don't really have to tag barra to learn whether or not they become gun shy or even how long they take to recover. Plenty of visual signs and observed behaviour from the fish exists to fill more than enough doubt.
4 kilograms of growth rate per year of life in Awoonga has been documented via tagging along with extreme distances covered since release as little ones, or as tagged maturing adults. Plenty of tags have been recovered from 6-8 yr old Awoonga fish.
Cheers,

Comparing Salt and Freshwater Barra by Size and Age

Two things to consider; Fish age is one major.
Salt fish can poke 30yrs of age or more, whilst our lakes like Proserpine, Monduran and Awoonga are less than about half that 30 yr figure. We have 30 kilo fish in these lakes and they will struggle to reach 40kg because of numerous reasons. Tinaroo has had big fish for a long time, probably the oldest in any impoundment, the most historical of stockings. 40kg+ fish exist in Tinaroo, yea!
The salt has 60kg + barra, but it is hard to compare two fisheries of different age. The salt has been rolling on and on for generations, the lakes are just a splash in the pan in reflection of fish potential and age maximum.
History shows that barra in the salt still hold the records for the longest and heaviest overall. If we had unfished giant stocked lakes that were 20 yrs old or more, similar to the size of the salt regions I'm sure some mega giants would come out of lakes, but all variables aligned, we do not have that; so in my experience, the salt is still the winner. My 7 best barra are all from the salt. 130-138cm. The best we have landed is 141cm. Truth be known, they are not big by salt standards. The targeting of large saltwater barra is not equal in lure fishing standard to that of lake fish that select smaller prey than the wide diet range of salt fish. More 30-40kg lake barra would be landed on 5 inch lures than if the same effort was applied in salt environments. Big saltwater barra love big food items. 2 kilo fish are prime fodder when they are keen to eat.
Salt wins, for the time still being.

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