The 'famous scientist' Walter Starck has gone to some effort to criticise fisheries management on the Great Barrier Reef by comparing catch per unit area, insisting that the fishing is being overly restricted. This is like a farmer in arid lands insisting he should be able to have the same stocking rates as one on the east coast.


freediver wrote on Jul 24^th, 2010 at 8:52am:

fishfinder wrote on Jul 24th, 2010 at 2:15am: I would have thought the important point would be not that CPUA is 100X lower on the GBR coral reefs than other reefs with different oceanography, biology and fishing methods etc.- but what CPUA can the GBR handle? We know quite a lot about the oceanography and biology of the GBR and fishing methods employed there. I don't think any other scientists have suggested ratcheting up the fishing pressure to that extent and it seems a pretty radical course of action based on a simple comparison and a lone voice. I'm no expert but I would have thought not all coral reef fisheries are the same. Temperate fisheries are not. Where I'm living in WA the entire demersal scalefish catch (of over 15 species) was ~1500t in an . It has been cut this year to ~750t to avoid 'high risk' of collapse of those fisheries. This fishery is spread over ~1000km of coastline. Just one of those species, Pink Snapper, in just one fishery zone in New Zealand - over about 100km of coastline - has an allowable catch of 4500t that is considered a sustainable yield. In other words one species in a fishery area a tenth of the size can produce six times more fish than all the fish in 1000km of coastline in Western Australia. To me, this suggests that fishery productivity varies widely. Exactly. You don't have to be an expert to figure that one out. Most people would laugh if a 'scientist' compared farm stocking rates in an arid region with those in a wet region and suggested this is a good way to judge whether stocking rates should be increased or decreased. It would get even more ludicrous if different animals from different parts of the food chain were being harvested and it was strongly impacted by size effects an inflows from surrounding regions. Yet this is what Walter does with the oceans. He and his devoted followers accept the absurd simplification that because they are both called a 'reef' it is reasonable to expect the same level of productivity. His analysis is based on the equivalent of ignorance of the difference between a desert and a jungle. I suppose you couldn't expect much more from a self described "pioneer in the scientific investigation of coral reefs" who does not have a single scientific publication in a peer reviewed journal.

PJ responded by claiming that the evidence suggests that the Great Barrier Reef is more productive, even though the evidence being presented was of lower yields.


pjb05 wrote on Jul 24^th, 2010 at 9:43am:

Also there is no evidence the GBR is less productive than these reefs. Actually it's probably more productive.

He then went on to suggest that because we target fish higher up the food chain than at the comparison sites, the catch rates should be higher. This is like saying you should be able to harvest more lions than you could buffalo on the African plains.


pjb05 wrote on Jul 24^th, 2010 at 1:43pm:

[] Quote: The fact that we don't target the herbivours like the susbsistence  fishermen of the South Pacific is a good thing, given their role in reef ecology. 2) Given that herbivores are lower on the food chain, they can support higher catch rates, so it is definitely a bad thing if you use this as a benchmark for judging the sustainability of catch rates for a fishery dominated by higher level carnivores. The evidence above suggests the contrary. And not all fish lower in the food chain are herbivours.

Even though genuine scientists balked at making the same conclusions as Walter when they made similar comparisons, and actually advised against it, PJ insits that they would have in this case:


Quote:

They weren't making comparisons with the GBR were they. If they were they may have well drawn the same conclusions as Walter.

pjb05 wrote on Jan 3^rd, 2011 at 10:26am:

date=1294011957] Just your selective amnesia at work again FD. Does this sound rational? - Catch per unit area is commonly used to compare fishing pressure on coral reefs.

I acknowledge that you went to the trouble of digging up a reference where another scientist made a similar comparison. The difference being that the genuine scientist advised against trying to draw the conclusions drawn by Walter. This is, of course, all in the post above that you were responding to.


Quote:

- Your knit-picking criticisms ignore the fact that the fishing pressure on the GBR was orders of magnitude below what is regarded as sustainable for coral reefs.

I am not ignoring it PJ. It is central to this argument. It is like the arid farmer insisting that his comparison is valid because coastal farmers have orders of magnitude higher stocking rates. The really big number does not make the comparison any less invalid.

Just your selective amnesia at work again FD. Does this sound rational?

- Catch per unit area is commonly used to compare fishing pressure on coral reefs.[/quote]

I acknowledge that you went to the trouble of digging up a reference where another scientist made a similar comparison. The difference being that the genuine scientist advised against trying to draw the conclusions drawn by Walter. This is, of course, all in the post above that you were responding to.

The paper didn't include the GBR. All the reefs assessed had fishing pressure orders of magnitude greater than the GBRIt did include a measure made by another scientist of about 100x the CPUA of the GBR being the maximum sutainable yield fo coral reefs. A conservation organisation puts it about half that - still orders of magnitude greater than the GBR.


Quote:

- Your knit-picking criticisms ignore the fact that the fishing pressure on the GBR was orders of magnitude below what is regarded as sustainable for coral reefs.

I am not ignoring it PJ. It is central to this argument. It is like the arid farmer insisting that his comparison is valid because coastal farmers have orders of magnitude higher stocking rates. The really big number does not make the comparison any less invalid.

Are you trying to say the GBR is less productive than other coral reefs? This not the case.
Are you trying to say catches there are a guide to abundance. And what about the other independant evidence I mentioned that the GBR is lightly fished?  

Quote:

The paper didn't include the GBR.

So what is special about the GBR that makes the comparison valid? Can you find a single genuine scientific paper that has suggested it is valid to draw conclusions about fisheries management from CPUA? So far the papers you have used as evidence advise against it.


Quote:

All the reefs assessed had fishing pressure orders of magnitude greater than the GBRIt did include a measure made by another scientist of about 100x the CPUA of the GBR being the maximum sutainable yield fo coral reefs. A conservation organisation puts it about half that - still orders of magnitude greater than the GBR.

Haven't I responded to this point twice already, in this thread alone? Do you disagree with my response, or do you simply not understand it?


Quote:

Are you trying to say the GBR is less productive than other coral reefs?

 

Probably, at least on a CPUA basis. There are many good reasons why it would be.


Quote:

Are you trying to say catches there are a guide to abundance.

They are a rough guide. Do you think the GBR has been so horribly mismanaged the whole time that we could have harvested 100X as many coral trout?


Quote:

And what about the other independant evidence I mentioned that the GBR is lightly fished?

 

I don't see how it could make Walter's analysis valid. To put it in terms you might understand, the arid land farmer may well be able to increase his stocking rates, but that doesn't make him any less of an idiot for arguing that a comparison with coastal areas is in any way useful in determining that.

]
Quote:

The paper didn't include the GBR.

So what is special about the GBR that makes the comparison valid? Can you find a single genuine scientific paper that has suggested it is valid to draw conclusions about fisheries management from CPUA? So far the papers you have used as evidence advise against it.

It they advised against it then why did they quote another scientist giving a CPUA limit of sustainability? I think you are taking one line out of proportion. PS I don't think it will be too hard to find other references.  


Quote:

All the reefs assessed had fishing pressure orders of magnitude greater than the GBR. It did include a measure made by another scientist of about 100x the CPUA of the GBR being the maximum sutainable yield for coral reefs. A conservation organisation puts it about half that - still orders of magnitude greater than the GBR.

Haven't I responded to this point twice already, in this thread alone? Do you disagree with my response, or do you simply not understand it?

Given you are so clueless that arrogant tone doesn't really suit you.


Quote:

Are you trying to say the GBR is less productive than other coral reefs?

 

Probably, at least on a CPUA basis. There are many good reasons why it would be.

The reasons are small population, remoteness, bad weather and restrictive fisheries management. Your confusing natural productivity with catches. The later is not a relaible guide to the former. There is no evidence the GBR is lacking natural productivity, actually it is more productive with more nutrients and larger fish.


Quote:

Are you trying to say catches there are a guide to abundance.

They are a rough guide. Do you think the GBR has been so horribly mismanaged the whole time that we could have harvested 100X as many coral trout?

See above. Most the GBR was hardly fished at all.


Quote:

And what about the other independant evidence I mentioned that the GBR is lightly fished?

 

I don't see how it could make Walter's analysis valid. To put it in terms you might understand, the arid land farmer may well be able to increase his stocking rates, but that doesn't make him any less of an idiot for arguing that a comparison with coastal areas is in any way useful in determining that.

It's coroborating evidence. Ie a different line of evidence leading to the same conclusion. If fish were being heavily fished then you would see a significant improvement in nos in the green zones for instance. I don't know what your rambling about a farmer and his stock means.  

Quote:

I don't know what your rambling about a farmer and his stock means.

Honestly?

I'm trying to keep up with this. It is interesting.


Quote:

There is no evidence the GBR is lacking natural productivity, actually it is more productive with more nutrients and larger fish.

Actually, Tropical waters are far less in nutrients than Temperate waters. Its a beautiful but deadly world in the GBR ...being nutrient poor - its a eat or be eaten system more so than Temperate.
Also, the GBR itself has shallower systems unlike open Tropical seas.

It_is_the_Darkness wrote on Jan 3^rd, 2011 at 11:34pm:

I'm trying to keep up with this. It is interesting. Quote: There is no evidence the GBR is lacking natural productivity, actually it is more productive with more nutrients and larger fish. Actually, Tropical waters are far less in nutrients than Temperate waters. Its a beautiful but deadly world in the GBR ...being nutrient poor - its a eat or be eaten system more so than Temperate. Also, the GBR itself has shallower systems unlike open Tropical seas.

Where talking about coral reefs - they aren't found in temperate waters.  

freediver wrote on Jan 3^rd, 2011 at 9:10pm:

Quote: I don't know what your rambling about a farmer and his stock means. Honestly?

Yep, it's nonsensical.

PS: all you have done in this thread is repeat the same mistakes you made originally.

Developing a desirable enthusiast for achieving each desire to create new paper to learn new things for designing.