Estimated Weights for GT

[Colin P]

[Luke Wyrsta]

I am not aware of any credible results or conclusions in the field of weighing GTs. GTs simply come too many size anomalies to apply a formula.

I would rather estimate the fish and be subject to the reaction that comes with it or use that time to weigh the fish in the safest manner pending available equipment. I don't mind people using the formula but I personally don't give the results any more credence than an estimate.

I applaud those trying to develop this formula but for me, it simply doesn't work.

At the end of the day - size/trophies/bragging is insignificant - fish well-being must be a priority if we wish to continue fishing for them.

[Andy Rowe]

At the end of the day - size/trophies/bragging is insignificant - fish well-being must be a priority if we wish to continue fishing for them.

Couldn't agree more.

[chris harrison]

I am in agreement with Luke,
i remember this debate being raised in 2006 on another forum with all kinds of extrapolations and formula's being raised. The upshot if there was any from that debate was that due to the lack of continuity of size and variation of GT and if they had come from deep water or coral reef was that there is no definitive formula that is 100% accurate but only a guide. We only need to look at the anomalies raised by the standard B.M.I for people which has had more money and time thrown at it.
The only sure way is to weigh the fish but do we really want to get into this?, surely fishing is not for the majority of us a competitive sport but a chance to see new locations meet people and watch the fish swim off healthily to delight another angler.

Chris

[Colin P]

Interesting views and of course it goes without saying that the vast majority of GT fishermen are more interested in the welfare than the weight of the fish they catch. That said, the vast majority of catch reports allude to the estimated weights of the biggest GT caught and many contributors express personal ambitions to top the 30, 40 or 50kg mark - so there is a widespread desire to have a decent idea of the weights of GT.

The Latham guys suggest that their formulae are based on accurately measuring the fork length and girth of a significant number of fish, then weighing them on certified scales - and they claim to be accurate within around 1.5kg. Their formulae may or may not be that accurate - but I suspect they will be more accurate than "finger in the air" estimates.

Personally I am satisfied that I have caught GT in excess of 30kg and whilst it is not the be all and end all of my of my GT fishing, I would like to catch a GT in excess of 40kg. I had a lot of fun fishing for GT on a recent trip to The Andamans without feeling the need to weigh or measure any GT caught - but I would have measured any fish that looked like it may challenge the 40kg mark and I would like to have had some confidence in the relative accuracy of any formula used to estimate the actual weight.

[Luke Wyrsta]

Interesting views and of course it goes without saying that the vast majority of GT fishermen are more interested in the welfare than the weight of the fish they catch. That said, the vast majority of catch reports allude to the estimated weights of the biggest GT caught and many contributors express personal ambitions to top the 30, 40 or 50kg mark - so there is a widespread desire to have a decent idea of the weights of GT.

The Latham guys suggest that their formulae are based on accurately measuring the fork length and girth of a significant number of fish, then weighing them on certified scales - and they claim to be accurate within around 1.5kg. Their formulae may or may not be that accurate - but I suspect they will be more accurate than "finger in the air" estimates.

Personally I am satisfied that I have caught GT in excess of 30kg and whilst it is not the be all and end all of my of my GT fishing, I would like to catch a GT in excess of 40kg. I had a lot of fun fishing for GT on a recent trip to The Andamans without feeling the need to weigh or measure any GT caught - but I would have measured any fish that looked like it may challenge the 40kg mark and I would like to have had some confidence in the relative accuracy of any formula used to estimate the actual weight.

Colin,

You do provide some valid points.

However, I base my opinion on the fact that there are so many GT anomalies out there and well documented occurrences of these formulas being wrong. I can't see how anyone can claim a formula could ever be more accurate than a estimation since there is not (and I predict  never will be) any consistency in these formula results. As Chris mentioned, this has also been proven true through Body Mass Index formulas and calculations.

At the end of the day, estimations are exactly that - estimates! There will always be those that under and over estimate and those that beg to differ otherwise, at least there is no false sense of accuracy that these so-called formulas could provide should they gain further acceptance.

GT physiology still boggles me to this day - it can be quite common to catch a specimens of the same length but have a weighed weight difference of over 15kg or even more. I guess it just goes to show how populations can differ and are obviously greatly affected by environment, food source, currents, depth, water temperature, longitude etc.

Luke

[Colin P]

Colin,

You do provide some valid points.

However, I base my opinion on the fact that there are so many GT anomalies out there and well documented occurrences of these formulas being wrong. I can't see how anyone can claim a formula could ever be more accurate than a estimation since there is not (and I predict  never will be) any consistency in these formula results. As Chris mentioned, this has also been proven true through Body Mass Index formulas and calculations.

At the end of the day, estimations are exactly that - estimates! There will always be those that under and over estimate and those that beg to differ otherwise, at least there is no false sense of accuracy that these so-called formulas could provide should they gain further acceptance.

GT physiology still boggles me to this day - it can be quite common to catch a specimens of the same length but have a weighed weight difference of over 15kg or even more. I guess it just goes to show how populations can differ and are obviously greatly affected by environment, food source, currents, depth, water temperature, longitude etc.

Luke

Hey Luke,

Don't wish to prolong this thread past its worth but a couple of points are worth making -

Length is nowhere near as important as girth in the weight of a fish. If you look at lake trout tables, based on thousands of measurements and weighings undertaken by Canada's Ministry of Natural Resources, an inch of girth adds far more to weight than an inch of length - my personal experiences of weighing and measuring lake trout suggests that these tables are accurate to within ounces in 20 pounds. I suggest that different girths is why GTs of the same length can have widely differing weights. I very much doubt that GTs of the same length and girth could have hugely differing weights 'cause I don't see how the fish's physiology could allow this.

Having said all that, we must all accept that any estimate, however constructed, is still just an estimate. The only value in a formula is if empirical evidence can show it to be accurate to within whatever tolerance the users of it wish to achieve. The Latham guys believe their formulae to be accurate to within around 1.5kgs. Since it is the work of seconds rather than minutes to accurately measure a fish before accurately weighing it, it is theoretically easy to validate their formulae. However, like most guys who fish for GT, I would only consider weighing a fish if appropriately fish-friendly equipment was available.

Even then, for me the real buzz is about that crashing take on a popper or stickbait and the immediate, gut-wrenching feel of being connected to something so poweful. Weights and measures fade far into the background at such times.

Cheers

Colin

[Luke Wyrsta]

Colin,

You do provide some valid points.

However, I base my opinion on the fact that there are so many GT anomalies out there and well documented occurrences of these formulas being wrong. I can't see how anyone can claim a formula could ever be more accurate than a estimation since there is not (and I predict  never will be) any consistency in these formula results. As Chris mentioned, this has also been proven true through Body Mass Index formulas and calculations.

At the end of the day, estimations are exactly that - estimates! There will always be those that under and over estimate and those that beg to differ otherwise, at least there is no false sense of accuracy that these so-called formulas could provide should they gain further acceptance.

GT physiology still boggles me to this day - it can be quite common to catch a specimens of the same length but have a weighed weight difference of over 15kg or even more. I guess it just goes to show how populations can differ and are obviously greatly affected by environment, food source, currents, depth, water temperature, longitude etc.

Luke

Hey Luke,

Don't wish to prolong this thread past its worth but a couple of points are worth making -

Length is nowhere near as important as girth in the weight of a fish. If you look at lake trout tables, based on thousands of measurements and weighings undertaken by Canada's Ministry of Natural Resources, an inch of girth adds far more to weight than an inch of length - my personal experiences of weighing and measuring lake trout suggests that these tables are accurate to within ounces in 20 pounds. I suggest that different girths is why GTs of the same length can have widely differing weights. I very much doubt that GTs of the same length and girth could have hugely differing weights 'cause I don't see how the fish's physiology could allow this.

Having said all that, we must all accept that any estimate, however constructed, is still just an estimate. The only value in a formula is if empirical evidence can show it to be accurate to within whatever tolerance the users of it wish to achieve. The Latham guys believe their formulae to be accurate to within around 1.5kgs. Since it is the work of seconds rather than minutes to accurately measure a fish before accurately weighing it, it is theoretically easy to validate their formulae. However, like most guys who fish for GT, I would only consider weighing a fish if appropriately fish-friendly equipment was available.

Even then, for me the real buzz is about that crashing take on a popper or stickbait and the immediate, gut-wrenching feel of being connected to something so poweful. Weights and measures fade far into the background at such times.

Cheers

Colin

Colin,

Quite clearly length is a variable in the formula and without it the formula is useless. I used the length example to illustrate just how different GT body profiles and proportions can be. It is obvious in this scenario that the girth is the contributing factor in the variance.

I see zero credibility in the formula and will not comment further on the issue as I believe my point has now been suitably proven.

[Brandon Khoo]

I think it really is a personal thing and it does to a degree comes down to what motivates you. I've been fishing for GTs for many years now and I suppose when I was a fair bit younger, I wouldn't deny that my personal satisfaction came from trying to beat my personal best in terms of size. Perhaps over the years and having had the opportunity to fish many different areas, I've changed. To be honest, the size of the fish isn't that important to me any more. What gives me the most satisfaction is simply having the opportunity to fish with good friends and being able to introduce new anglers to the sport and having the satisfaction of seeing the joy it gives them to land their first good fish. I took as much pleasure out of the fish which Paul and Tak caught recently at BUgatti as they did.
 
For years, I was in pursuit of the magic 70kg fish and I had a couple of chances but I think the reality today is that even if I hooked that fish, I simply couldn't land it. I think I am best leaving this to the young anglers like Luke who have the fitness to outlast such a fish. On the other hand, if I did manage to land such a fish after passing the rod back and forth with a good friend, it'd be be as special as if I landed it myself but what would be every bit as important would be ensuring the fish survived the fight to test another angler another day.

[Colin P]

I think it really is a personal thing and it does to a degree comes down to what motivates you. I've been fishing for GTs for many years now and I suppose when I was a fair bit younger, I wouldn't deny that my personal satisfaction came from trying to beat my personal best in terms of size. Perhaps over the years and having had the opportunity to fish many different areas, I've changed. To be honest, the size of the fish isn't that important to me any more. What gives me the most satisfaction is simply having the opportunity to fish with good friends and being able to introduce new anglers to the sport and having the satisfaction of seeing the joy it gives them to land their first good fish. I took as much pleasure out of the fish which Paul and Tak caught recently at BUgatti as they did.
 
For years, I was in pursuit of the magic 70kg fish and I had a couple of chances but I think the reality today is that even if I hooked that fish, I simply couldn't land it. I think I am best leaving this to the young anglers like Luke who have the fitness to outlast such a fish. On the other hand, if I did manage to land such a fish after passing the rod back and forth with a good friend, it'd be be as special as if I landed it myself but what would be every bit as important would be ensuring the fish survived the fight to test another angler another day.

You are as ever Brandon, a voice of gentle reason - and a reasoned debate was what I was seeking.

If other anglers have disproved the validity of e.g. the Latham formulae by accurately weighing significant numbers of fish that do not produce the weights the Latham formulae would suggest, then the formulae are indeed invalid - and that is the only way they can be proved so.

[Malcolm Crane]

Whilst I have no desire to prolong this discussion on the "weight" issue of GT's, there is one point I would like to raise. I feel this discussion was bought into the open again by the fact that one of the guides on Nomad is measuring fork length and girth of the fish landed. What is being missed here is in actuality there is no "formula" being applied in this case to determine the weight of the fish. Rather the guide is simply using his experience to estimate the weight based on his visual impression of the fish tempered by what the length and girth may indicate to him. In no way was he applying a "magic formula" and when pressed on the subject was happy to admit that. In other words a very experienced guide was simply making an estimate but goes the extra few yards by making some measurements to assist him in his guesswork.
The trap here is that the anglers on board in seeing this process tend to feel (very understandably) that what they are witnessing is a scientific absolute. It's not - it's an estimate.

Personally, I have been really pleased to notice of late a really healthy trend. It can be seen in particular amongst a group of very experienced French GT anglers who have all been active on various forums over the years. In times past they were heavily involved in heated debates on the "weight" of GT's, to the extent that these debates actually contributed to the demise of a forum. Recently however these anglers no longer talk numbers, but simply describe their captures as a "good" fish, a "very good" fish or occasionally a "huge" fish. These guys have grown with the sport and their attitude is admirable.

[Stephen Polzin]

Personally I'd prefer to see a shift in emphasis from weight to length, as in Barra fishing. 

Doesn't injure the fish and can't be disputed, especially if you get a pic on a brag-mat.  Of course fork length would be most appropriate for trevs. 

The only way to get an accurate weight on a trev is to kill it and hang it off a scale on dry land.

cheers,

steve

[Colin P]

Whilst I have no desire to prolong this discussion on the "weight" issue of GT's, there is one point I would like to raise. I feel this discussion was bought into the open again by the fact that one of the guides on Nomad is measuring fork length and girth of the fish landed.

Not true Malcom. I raised the issue thinking it may be of general interest, partly because in my travels I have noted different methods applied to gauge GT weights (I was interested to hear of other anglers experiences in this regard), partly because most catch reports describe estimated weights of the biggest fish caught (I assumed that most anglers were interested in the weights of their biggest captures).

I do agree that there would be no need for formulae or estimates if all GT anglers followed the example of the French guys you describe.

[Graham Scott]

I like Stephen's approach, try and shift the emphasis to length which is quick and easy. Many of our local iconic species (Central Queensland)are now generally described by length. Overheard in the tackle shop an old guy saying he caught a 15 kg barramundi and a young guy replied "Wow! How long was that one? Did it make a metre?"

I also caught a couple of 85cm red emperor last trip and I was very proud of a 91cm Nannygai on my baitcaster. No idea how heavy.

The world is changing!