Australian Politics Forum - Almost half of our species fully or overfished

freediver

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Almost half of our species fully or overfished
Jun 7^th, 2011 at 9:48pm

http://www.vcc.vic.gov.au/coasttocoastproceedings/BOHM_Craig_paper.pdf

Quote:

Our oceans are in trouble. Three quarters of global fish stocks are fully exploited, over-exploited or depleted and Australia’s Bureau of Rural Sciences has declared that almost half of Australia’s 70 principle fish species are fully fished or overfished.

Meanwhile, fishing pressure continues to increase for many reasons.

What this means is that continually stricter regulations will be necessary as more pressure is put on stocks. It means that the constant cries that our waters are underfished and need no further regulation are unfounded. It also means that the resilience of fish stocks will be put to the test and we risk more of the collapses seen overseas (and here already on several occasions). Catch limits, size limits, TACs etc become increasingly less effective as stocks come under more pressure because none of them can actually prevent overfishing of the remaining stock. If a fish stock collapses a bag limit or TAC is not going to protect the few that remain. Nor can these methods respond to the natural year to year variability in fish numbers and reproductive success. It gets even harder if you expect them to cope with unpredictable changes cascading up and down the food chain as we put more pressure on different trophic levels. Many even make the situation worse. You don't see farmers killing the big cows and returning the runts to the paddock as breeders for next year, but if you listen to the whingers apparently this sort of thing works just fine for our fish stocks and should be encouraged.

So, you get what happened with the snapper stocks in SE QLD. Improvements to sounder technology mean fishermen literally spend more time crusing round in their boats looking for them on the screen than with lines in the water - a reflection both of the improvements in the technology and the impact this has had on stocks. So we had to completely ban snapper fishing for six weeks. Expect more of the same.

What is needed is an inherently resilient method for managing fishing pressure and protecting remaining broodstock that becomes more effective rather than less effective as pressure on stocks increases or stocks drop for any reason.

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Jason Crowther

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Re: Almost half of our species fully or overfished
Reply #1 - Jun 7^th, 2011 at 10:02pm

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If a fish stock collapses a bag limit or TAC is not going to protect the few that remain. Nor can these methods respond to the natural year to year variability in fish numbers and reproductive success. It gets even harder if you expect them to cope with unpredictable changes cascading up and down the food chain as we put more pressure on different trophic levels. Many even make the situation worse. You don't see farmers killing the big cows and returning the runts to the paddock as breeders for next year, but if you listen to the whingers apparently this sort of thing works just fine for our fish stocks and should be encouraged.

You didn't even look at the WA fisheries report that has fully debunked your above garbage

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pjb05

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Re: Almost half of our species fully or overfished
Reply #2 - Jun 8^th, 2011 at 7:09pm

freediver wrote on Jun 7^th, 2011 at 9:48pm:

http://www.vcc.vic.gov.au/coasttocoastproceedings/BOHM_Craig_paper.pdf

Meanwhile, fishing pressure continues to increase for many reasons.

.

Didn't WA fisheries recently reduce the rec catch by 50% of snapper and duhfish etc by using traditional means?

PS: good quality sounders have been around for 30 years or more and cruising around with the sounder on is not the most effective way of catching snapper.

What about the displaced commercial effort from the GBRMP? I have heard that is added pressure to snapper stocks in SE Qld.

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« Last Edit: Jun 8^th, 2011 at 8:02pm by pjb05 »

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pjb05

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Re: Almost half of our species fully or overfished
Reply #3 - Jun 8^th, 2011 at 8:13pm

Meanwhile, fishing pressure continues to increase for many reasons.

What evidence do you have that our fishing effort is increasing when Commowealth boats have been reduced from 1200 to 600? There have been similar or larger reductions by various State fisheries as well.

What this means is that continually stricter regulations will be necessary as more pressure is put on stocks.

How do you get both at the same time?

It means that the constant cries that our waters are underfished and need no further regulation are unfounded. It also means that the resilience of fish stocks will be put to the test and we risk more of the collapses seen overseas (and here already on several occasions). Catch limits, size limits, TACs etc become increasingly less effective as stocks come under more pressure because none of them can actually prevent overfishing of the remaining stock. If a fish stock collapses a bag limit or TAC is not going to protect the few that remain. Nor can these methods respond to the natural year to year variability in fish numbers and reproductive success.

The main mangement tool used in our waters is input reductions eg limiting the number of boats, the gear they can use closed seasons etc.

It gets even harder if you expect them to cope with unpredictable changes cascading up and down the food chain as we put more pressure on different trophic levels. Many even make the situation worse.

Poorly designed marine parks can lead to adverse changes in species assemblages.

You don't see farmers killing the big cows and returning the runts to the paddock as breeders for next year, but if you listen to the whingers apparently this sort of thing works just fine for our fish stocks and should be encouraged.

Looks like someone else doesn't know the difference between terrestial mammals and fish stocks.

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freediver

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Re: Almost half of our species fully or overfished
Reply #4 - Jun 8^th, 2011 at 10:00pm

Quote:

You didn't even look at the WA fisheries report that has fully debunked your above garbage

How so Jason? Does natural selection work backwards in WA?

Quote:

Didn't WA fisheries recently reduce the rec catch by 50% of snapper and duhfish etc by using traditional means?

So you agree with me - What this means is that continually stricter regulations will be necessary... ?

Quote:

How do you get both at the same time?

More people wanting to go fishing, and more economic pressure to catch fish, better technology and resources etc. Simple really. That's why we have more fishing regulations and less fish in the ocean than the aborigines did (yes, both at the same time).

Quote:

The main mangement tool used in our waters is input reductions eg limiting the number of boats, the gear they can use closed seasons etc.

These are largely catch-up responses to dwindling catches and other restrictions. There is still over-capacity - more than enough to overharvest stocks if things start to go wrong. Cuts to number of boats are largely a political response to the historical mismanagement or changes to technology making fishing licences useless of unprofitable.

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Poorly designed marine parks can lead to adverse changes in species assemblages.

In your fevered imagination and hypotheticals that have little connection to the real world they can. In reality, they don't.

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Looks like someone else doesn't know the difference between terrestial mammals and fish stocks.

What is the difference? The theory of natural selection only applies to terrestrial mammals?

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pjb05

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Re: Almost half of our species fully or overfished
Reply #5 - Jun 9^th, 2011 at 5:34pm

Quote:

Didn't WA fisheries recently reduce the rec catch by 50% of snapper and duhfish etc by using traditional means?

So you agree with me - What this means is that continually stricter regulations will be necessary... ?

The point was that Fisheries worked out what reduction was needed to ensure sustainability and did so without the cost, divisiveness and other problems of marine parks. Your the only one saying, in rhetorical flight of fancy, that such restricts will ever tighten.

Quote:

How do you get both at the same time?

More people wanting to go fishing, and more economic pressure to catch fish, better technology and resources etc. Simple really. That's why we have more fishing regulations and less fish in the ocean than the aborigines did (yes, both at the same time).

In some places it is declining without any regulations, there were more boats of Sydney in the 1980's than there are now. I have also established you didn't know what you were talking about with your depiction of anglers pinging the depths with their unfair high tech depth sounders for the remaining snapper.

Quote:

The main mangement tool used in our waters is input reductions eg limiting the number of boats, the gear they can use closed seasons etc.

These are largely catch-up responses to dwindling catches and other restrictions. There is still over-capacity - more than enough to overharvest stocks if things start to go wrong. Cuts to number of boats are largely a political response to the historical mismanagement or changes to technology making fishing licences useless of unprofitable.

Your talking rubbish. Have a look at the Pitcher and Forrest article, specifically:

"Reduction in catches after the initial phase of a fishery is an inevitable part of fishery development and provides no evidence whatsoever as to the sustainability of a fishery".

Quote:

Poorly designed marine parks can lead to adverse changes in species assemblages.

In your fevered imagination and hypotheticals that have little connection to the real world they can. In reality, they don't.

Prof Colin Buxton's review of Tasmanian marine parks found this effect.

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Looks like someone else doesn't know the difference between terrestial mammals and fish stocks.

What is the difference? The theory of natural selection only applies to terrestrial mammals?

Don't keep playing dumb! There is a huge difference as I have explained.

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« Last Edit: Jun 10^th, 2011 at 4:44pm by pjb05 »

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freediver

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Re: Almost half of our species fully or overfished
Reply #6 - Jun 13^th, 2011 at 7:19pm

Quote:

The point was that Fisheries worked out what reduction was needed to ensure sustainability and did so without the cost, divisiveness and other problems of marine parks.

PJ, I never claimed that it is impossible to manage fish stocks without marine parks. All new regulations are divisive, because some people are afraid of change. Our current fisheries management tools were also at one time divisive new suggestions that had all the fishermen whinging. That is not a rational argument against change.

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Your the only one saying, in rhetorical flight of fancy, that such restricts will ever tighten.

PJ, you are truly naive and out of touch with the realities of the fishing industry if you think they won't get tighter. It is inevitable.

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I have also established you didn't know what you were talking about with your depiction of anglers pinging the depths with their unfair high tech depth sounders for the remaining snapper.

No you haven't. Can you offer some other explanation for why a complete ban was necessary.

Quote:

Your talking rubbish. Have a look at the Pitcher and Forrest article, specifically:

PJ, can you explain how this is relevant to what I posted?

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Don't keep playing dumb! There is a huge difference as I have explained.

I must have missed that. Can you link me to where you explained how fish are magically protected from the effect of selective pressures?

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pjb05

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Re: Almost half of our species fully or overfished
Reply #7 - Jun 13^th, 2011 at 8:21pm

[] Quote:

The point was that Fisheries worked out what reduction was needed to ensure sustainability and did so without the cost, divisiveness and other problems of marine parks.

PJ, I never claimed that it is impossible to manage fish stocks without marine parks. All new regulations are divisive, because some people are afraid of change. Our current fisheries management tools were also at one time divisive new suggestions that had all the fishermen whinging. That is not a rational argument against change.

You claimed that they are the ideal fisheries managment tool didn't you? Are you sure your just not making it up when you refered to the current fisheries mamgement tools were at one time having all fishermen whinging. You don't seem to know much about the current fishing scene let alone 30 or more years ago.

Quote:

Your the only one saying, in rhetorical flight of fancy, that such restricts will ever tighten.

PJ, you are truly naive and out of touch with the realities of the fishing industry if you think they won't get tighter. It is inevitable.

If they are fished at or below maximum sustainable yield then they can be fished at that rate indefinitely. Even if they are overfished sustainability will be reached long before you can fish for snapper one day a year!

Quote:

I have also established you didn't know what you were talking about with your depiction of anglers pinging the depths with their unfair high tech depth sounders for the remaining snapper.

No you haven't. Can you offer some other explanation for why a complete ban was necessary.

Nothing to do with some sort of arms race using echo sounders. PS: it's not a 'total ban', it's a six week closed season. Remember I also said it is debatable whether the closed season is necessary.

Quote:

Your talking rubbish. Have a look at the Pitcher and Forrest article, specifically:

PJ, can you explain how this is relevant to what I posted?

Your saying that an increase in restrictions and reduction in catches is a sign of failure and it is inevitable that they will be ever increasing restrictions. The quote debunks that. You might like to read the whole paper. It shows the difference between uniformed advocacy and science.

Quote:

Don't keep playing dumb! There is a huge difference as I have explained.

I must have missed that. Can you link me to where you explained how fish are magically protected from the effect of selective pressures?

For a starters there is the fact that fish actually grow faster under fishing pressure. Also there have been some remarkable recoveries when fishing pressure has been wound back eg salmon & kingfish in NSW. Hardly signs of adverse genetic changes.

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freediver

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Re: Almost half of our species fully or overfished
Reply #8 - Jun 13^th, 2011 at 9:18pm

Quote:

Your saying that an increase in restrictions and reduction in catches is a sign of failure and it is inevitable that they will be ever increasing restrictions. The quote debunks that.

No it doesn't. That is just silly PJ. It is a logical fallacy. Saying that it is possible to have a decline in stocks that is not indicative of overfishing does not magically prove that all declines in stocks are healthy.

Quote:

You might like to read the whole paper. It shows the difference between uniformed advocacy and science.

Apparently not.

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pjb05

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Re: Almost half of our species fully or overfished
Reply #9 - Jun 14^th, 2011 at 6:28pm

] Quote:

Your saying that an increase in restrictions and reduction in catches is a sign of failure and it is inevitable that they will be ever increasing restrictions. The quote debunks that.

No it doesn't. That is just silly PJ. It is a logical fallacy. Saying that it is possible to have a decline in stocks that is not indicative of overfishing does not magically prove that all declines in stocks are healthy.

Aren't you the one saying any new traditional restriction will inevitably result in ever more such restrictions? Don't twist your illogical argument around and throw it back at me.

Quote:

You might like to read the whole paper. It shows the difference between uniformed advocacy and science.

Apparently not. [/quote]

Have you read it? Where do you find fault?

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freediver Gold Member Offline www.ozpolitic.com Posts: 47460 At my desk.	Re: Almost half of our species fully or overfished Reply #10 - Jun 14^th, 2011 at 9:51pm Quote: Aren't you the one saying any new traditional restriction will inevitably result in ever more such restrictions? No.
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pjb05 Gold Member Offline OzPolitic Posts: 1402 Gender:	Re: Almost half of our species fully or overfished Reply #11 - Jun 15^th, 2011 at 5:05pm freediver wrote on Jun 14^th, 2011 at 9:51pm: Quote: Aren't you the one saying any new traditional restriction will inevitably result in ever more such restrictions? No. Then you have changed you mind since you began this thread.
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freediver Gold Member Offline www.ozpolitic.com Posts: 47460 At my desk.	Re: Almost half of our species fully or overfished Reply #12 - Jun 16^th, 2011 at 8:22pm I did not imply the causation you did.
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pjb05 Gold Member Offline OzPolitic Posts: 1402 Gender:	Re: Almost half of our species fully or overfished Reply #13 - Sep 3^rd, 2011 at 8:30pm FD, could you tell me what is terribly wrong with a species being fully fished? PS, is the number of overfished species increasing or declining?
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freediver

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Re: Almost half of our species fully or overfished
Reply #14 - Sep 4^th, 2011 at 7:18pm

The number of overfished species is increasing.

Nothing wrong in general with a species being fully fished. It just contradicts the impression many have of underfishing. It also implies that restrictions will need to become tighter as fishing pressure increases - that is, a fully fished species is not far from being overfished. There is a great deal of uncertainty in fisheries management so it is hard to keep on the right side of that line.

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