Beginning of the end of GBR fishing adventures...?

[Kev_McC]

Off the original topic, sorry…but there’s significant research indicating the benefits of green zones to fish stocks outside the green zones. However that’s not to say that improvements can’t be made, that’s the basis of what science is - continually questioning. If the science now indicates that the same benefits might be obtained from more explicit targeting of the most important areas into a smaller overall area of no-take zones, with smarter catch restrictions, then we should go for it.

[billfisher]

Off the original topic, sorry…but there’s significant research indicating the benefits of green zones to fish stocks outside the green zones. However that’s not to say that improvements can’t be made, that’s the basis of what science is - continually questioning. If the science now indicates that the same benefits might be obtained from more explicit targeting of the most important areas into a smaller overall area of no-take zones, with smarter catch restrictions, then we should go for it.

Any talk of an overall benefit is stretching a long bow. Yes there are modestly positive differences between green and fished zones, but such conclusions are only arrived at by overlooking evidence of displaced fishing pressure and green zones being more productive in the first place. Also the catch and effort data has to be looked at before drawing such conclusions. Stocks of the most fished species, coral trout, were very robust prior to the expansion of green zones to 33%, and there were reductions in commercial fishing under fisheries management since then. There is evidence that fisheries management has to bee pretty poor to absent for there to be any significant spill over from green zones:

When Is Spillover from Marine Reserves Likely to Benefit Fisheries? (plos.org)

Here is the article I was referring to regarding smaller green zones:

https://theconversation.com/how-ecos...them-too-29977

[Kev_McC]

Yep I have not considered the impact of displaced effort - seems logical that the remaining areas would be negatively affected. However there’s been a lot of studies into the benefits or otherwise of marine protected areas and the overall impact leans toward the positive. Not in every case of course.
The research I’m most familiar with has been going on in Keppel Bay and established that over 80% of the coral trout in the region came from parents that inhabit green zones, about 28% of the area in that region. From memory it was about 50% of stripey snapper.
I read the article in The Conversation, and some of the published research it refers to, and I’m agreeing with you that it could be done better. In practice this means a smaller network of no-take zones, with lower allowable take by commercial and rec sectors (lower bag limits, slot limits, protection for spawning aggregations etc). This also means a much higher level of enforcement. The green zones really are the crudest blunt instrument, and probably the cheapest. The (better) alternatives need more research, monitoring and enforcement.
Also worth remembering that the green zones may have been more about limiting trawling impact (bottom disturbance, bycatch) and mining development as they were about finfish caught by rec fishers.

[Lovey80]

Trawlers don’t trawl reef.

[NAGG]

Trawlers don’t trawl reef.

Not all green zones are reef though

Chris

[billfisher]

Yep I have not considered the impact of displaced effort - seems logical that the remaining areas would be negatively affected. However there’s been a lot of studies into the benefits or otherwise of marine protected areas and the overall impact leans toward the positive. Not in every case of course.
The research I’m most familiar with has been going on in Keppel Bay and established that over 80% of the coral trout in the region came from parents that inhabit green zones, about 28% of the area in that region. From memory it was about 50% of stripey snapper.
I read the article in The Conversation, and some of the published research it refers to, and I’m agreeing with you that it could be done better. In practice this means a smaller network of no-take zones, with lower allowable take by commercial and rec sectors (lower bag limits, slot limits, protection for spawning aggregations etc). This also means a much higher level of enforcement. The green zones really are the crudest blunt instrument, and probably the cheapest. The (better) alternatives need more research, monitoring and enforcement.
Also worth remembering that the green zones may have been more about limiting trawling impact (bottom disturbance, bycatch) and mining development as they were about finfish caught by rec fishers.

The Keppel Bay larval export study made the same mistake of ignoring displaced effort and higher natural productivity of the green zones despite it being described in the literature for that area. Also the larval dispersion would only be of benefit if there was a shortage of larvae and there is no evidence of this. They didn't do any analysis of the catch data either. Prof Colin Buxton and Caleb Gardener took them to task on this in the comments section and the authors seemed to back way from any fishery wide benefits.

[billfisher]

Trawlers don’t trawl reef.

Yes it would be putting the boat at risk.

[billfisher]

Not all green zones are reef though

Chris

But on the other hand several States have area bans on trawling bigger than any of the marine parks they host.

[billfisher]

. In practice this means a smaller network of no-take zones, with lower allowable take by commercial and rec sectors (lower bag limits, slot limits, protection for spawning aggregations etc). This also means a much higher level of enforcement. The green zones really are the crudest blunt instrument, and probably the cheapest. The (better) alternatives need more research, monitoring and enforcement.

The Conversation points out that this will mean less expensive enforcement. All those restrictions are in place already and it's just a matter of tweaking them and not by all that much. Many can be checked back at the wharf or boat ramp. Green zones on the other hand require expensive patrols including aerial ones.

[disorderly]

Some interesting points there on Green zones and other alternatives...

I think we can all agree that boating/fishing/diving pressure is continually increasing in GBMPA waters and that measures need to be taken to lessen the effects of these pursuits...

last year alone there were 18000 new boat rego's in the country...and at total of over 250 000 rego-ed in QLD now.....

Here is the zoning pic of my area..

You can plainly see what they were trying to acheive by green zoning reefs in regular intervals along the length of it..

You can also see that more then 2/3 of the green zones are not even in the "reef zone"..basically just out in the "paddock" inside and outside the actual reef where there is little to no structure and very few people actually fished there anyway..

innisfail green zones.jpg

and yep there are the issues that shutting down some reefs will place added pressure on the rest...and its always going to be extremely difficult to determine with a good deal of accuracy the true benefits of the green zone's ...

Likewise shutting down completely the Spanish mackeral fishery and maybe the Nannigai after that will also place added pressure on other species..

perhaps just reducing bag limits on these species and overall boat limits would be the wisest decision overall ...

Anyway as a keen recreational scuba and free diver I love that we have reefs that are off limits to most fisherman (shame that not all are) and having dived in all those green zone reef area can honestly say they are more "fishy" and have more coral trout in them then anywhere else we dive..(except for the one directly off Mourylian harbour which has recently been decimated by COTS)......not very scientific i know but I also wonder how much of the science being bandyed around are from incomplete or inaccurate data anyway .. its just so difficult to realistically quantify some of these stats..

One benefit of the reef zoning with green, pink and yellow zones that shouldnt be discounted is the huge concession thats been given towards reef conservation as a result..we are always going to have to give up some things so i think its a fair compromise......

[chris69]

Not all the green zones apply to fish up in your area out wide is king prawn country and what gets me is mackerel follow the bait so if the bait is not around neither are the mackerel or they can be late or early ,in the last few year they have gone past moreton bay and showed up in good numbers over the boarder mid nsw coast so I'm wondering how much of migration movements are taken into consideration when decisions are made.

[billfisher]

Rec fishing has been stable or falling in some States over the medium to long term.

[disorderly]

Rec fishing has been stable or falling in some States over the medium to long term.

I thought we were discussing QLD....

What do your figures suggest here...?

Then add in spotlock trolling motors, increasingly affordable, state of the art, sonar/transducer and seafloor mapping technology and booming online fishing tutorials/lessons, youtube video's etc..

But you believe whatever suits your narrative..thats your right..

[billfisher]

I thought we were discussing QLD....

What do you figures suggest here...?

Then add in spotlock trolling motors, increasingly affordable, state of the art, sonar/transducer and seafloor mapping technology and booming online fishing tutorials/lessons, youtube video's etc..

But you believe whatever suits your narrative..thats your right..

Well you haven't provided any angling participation data for Qld either. I have heard claims like that for NSW and when I looked it up participation has actually been stable for 20 or so years. Also better methods will show up in catch data if all things are equal They are not though with a lot of tightening of size and bag limits, closed seasons, etc.

[disorderly]

and, on top of all that, net migration growth is currently at record levels to QLD.

So you are basing the catch data and participation levels on some random data collected from haphazard , random and irregular ramp surveys...?

Thats laughable..

No one I know has ever even been approached or surveyed.

So please leave out anecdotal evidence about NSW and other states...This thread is about QLD and more specifically GBR waters..