MPAs as Management Tools... A scientific study

[Kelsea]

A penny for your thoughts on this article and its corresponding PLoS ONE Scientific Journal article (peer-reviewed).... And please, keep the discussion civil and constructive. This is not a venting thread - I'd rather have an actual discussion about the science here...

Science Daily Article:

http://www.sciencedaily.com/releases...1109142129.htm

Corresponding Peer-reviewed Journal Article:

http://www.plosone.org/article/info%...l.pone.0004140

[Kelsea]

Some interesting points I highlight from the article...

"Subsequent events, however, underscored the role of social factors in the success of fishery management efforts. A second paper, published in PLoS ONE in July, describes how, after its initial success, the local reserve system collapsed due to poaching by outsiders.
"The whole thing got wiped out due to disruption of the social structure that had supported it," Raimondi said. "Scientifically it was really interesting, but for the people who experienced it on the ground, it was terrible."

"We found that local control of community resources can work, but there has to be broader government support to back up the local efforts."




This is very important. Pay attention, because what we do matters:

According to Carr, the California MLPA process is now being used as a model in other parts of the world, most notably in the United Kingdom.

[Urchin_Diver]

sorry kels, just pounded several pints of stone ipa and didnt want to read all this scientific shit, i guess thats what we lowly fishermen do when we dont work. But it sounds like it sucks and i'll cruise by tomorrow at the meeting and check it all out

[rojodiablo]

What you quoted was really important; without buy-in and support, the MPA's do not work. The area described was a spot called Sugarloaf rock. And all the tiny lobster you get in resteraunts at Puerto Nuevo come from there. The pangas from all over came and wiped it out, as well as....the locals. Imagine how many lobster are stolen by Laguna regulars who have access to places like Cameo shores, where so much trap robbing goes on. The average person is not diving there; it's private. Their little private hunting ground, that's what MPA's make.

I have been to the Revilla, and SEEN the seiners in working where we used to anchor and catch 200-300lb tuna. Yep, for a price, you can buy anything.

[SDspearo]

It appears from the article that MPAs work when designed and supported by the users of the resource with adequate enforcement to prevent poaching. To bad none of that is present in the current California scheme. Its not users designing the maps, its those that want no use. And there is no money for enforcement.

[emrliquidlife]

This is exactly what I was commenting during the public comments section.

This is the paper I was using:

http://www.coralseas.com/doc/Jameson...2002%20MPB.pdf

We have out and out dissent for the Dume area.

[ekinoderminator]

The science is easy to understand - higher recruitment for density dependant species leading to spill over. It will be tough for those who's spots will become MPA's - some of mine will. Sometimes I think one day of commercial fishing has ten times more impact than 365 days of recreational and that we rec guys shouldn't be limited by the historical mismanagement of the commercial fisheries. My thoughts on this are unrefined and just off the cuff. It is interesting also how we embrace the MPA's that have been in existence - if a diver fished Gerstle Cove I think he would be beaten with a barrage of ab irons. Hopefully we'll be getting some good spill over soon - of course it will take some serious time with species such as copper rockfish, that live to be 50.

[rojodiablo]

Originally Posted by ekinoderminator

The science is easy to understand - higher recruitment for density dependant species leading to spill over. It will be tough for those who's spots will become MPA's - some of mine will. Sometimes I think one day of commercial fishing has ten times more impact than 365 days of recreational and that we rec guys shouldn't be limited by the historical mismanagement of the commercial fisheries. My thoughts on this are unrefined and just off the cuff. It is interesting also how we embrace the MPA's that have been in existence - if a diver fished Gerstle Cove I think he would be beaten with a barrage of ab irons. Hopefully we'll be getting some good spill over soon - of course it will take some serious time with species such as copper rockfish, that live to be 50.

I think you're assesment of commercial fishing might be off by a wide margin in many cases, especially when you talk about species most likely to benefit. Urchin?? Sure, the commercial take is 99% of the take total, but are urchins overfished?? Now, what about lobster?? I can tell you; the recreational lobster take is not that far off the commercial take. Look at the data, and see what the lobster report card point toward.
Now, species like squid?? They are not protected at all by an MPA. They are pelagic, and as they move, they are a target. Now, what of larval dispersal?? The theory behind it is that the fish inside the MPA will spawn, and their larvae will seed the rest of the enviroment. GREAT......but what an epic failure of science. For this to hold true, there would have to be NO spawn from any other areas seeding any areas. Is that the case?? Would you say that a rockfish stock at Cambria NOT be successful enough spawners, vs. the unfished rockfish population just down the coast below Montana Del Oro??? The truth is, size and spacing is a farce designed to force us to give up habitat. The truth is, there are so many other successful spawning fish between the MPA's, there is no chance that we will ever see a benefit in the overall fishery, vs. a limited success of not removing some of the adult fish inside an MPA. This is not off the cuff, but a series of facts well pointed out and versed by Dr. Ray Hilborn, one of the leads of the SAT for the MLPA.

[ekinoderminator]

I agree that the commercial/rec take is more equal in southern california. In Northern I think it's much more lopsided regarding fish, crab, urchin to commercial and abs to rec. The way I see it up north abs are being managed fine and the rec guys will suffer for the mismanagement of the commercial.

I think the science anticipates equal amounts of recruitment and spawning in the beginning and more spawn/recruitment in the MPA's as time passes and the MPA's have their effect. I think it is the various rockfish that have long life cycles and are not pelagic that will benefit. Larger females produce way more eggs than small females. I can't see why any science would anticipate recruitment to only be successful in an MPA -

you said: "Now, what of larval dispersal?? The theory behind it is that the fish inside the MPA will spawn, and their larvae will seed the rest of the enviroment. GREAT......but what an epic failure of science. For this to hold true, there would have to be NO spawn from any other areas seeding any areas. Is that the case?? Would you say that a rockfish stock at Cambria NOT be successful enough spawners, vs. the unfished rockfish population just down the coast below Montana Del Oro???"

why do you think there would have to be NO recruitment from areas outside an MPA for recruitment to have a "spill out" effect from an MPA? It seems obvious to me that there will be varying levels of recruitment all over.

You mention "larvae" -that applies to urchins, lobster, crab, abalone, NOT fish. By setting minimum sizes those shellfish are easily managed.

I agree that pelagics will have little benefit rom MPA's and in fact will likely see more pressure as they will be targeted more because of the MPA's.

Where I have my biggest problem with the science behind MPA's is that pressure will increase greatly in non MPA areas and some species may suffer as a result.

Again, my thoughts on all this are not refined and in development.

[rojodiablo]

Fish larvae are definitely in my count. Many of the fish are live birth, but many are broadcast egg spawners. And rockfish spawn ride the currents and settle out after a given set of time, it usually runs about 50 days or so, with fish like sheephead spawn taking as much as 80 days to settle in on a structure. With the dispersal models, the theory that is used insinuates that the MPA's need to be X miles apart so one MPA can seed another by current, using larval dispersal by current. It is BS, simply because for it to ring true, that would mean there were NO spawning fish/ abs, etc. in the areas between the MPA's. And it is simply impossible to have happen that way.
The truth is, the open areas will seed the MPA's far better than the MPA's will seed themselves, as there is by volume much more fish and habitat combined outside MPA's than the ocean is given credit for. Not to mention, small spawning groups just outside an MPA will seed into the nearby MPA far more effectively than another MPA some 30 miles away. This is where I get pissed about size and spacing guidelines. They are pure shit because of this.
Your last post clears up a lot of the vagueness of your quoted post; thanks for helping guide the discussion. That is not always easy to do with fisheries management talk....

[ekinoderminator]

I see now that several of our fish go through the larval stage. Still I don't see why the science behind the MPA placement would anticipate zero recruitment from non MPA - it seems so obvious that recruitment would be at varying levels throughout. The group of animals I see this benefiting the most are those rockfish that tend to hang in one spot more or less.

[Kelsea]

Originally Posted by rojodiablo

The truth is, size and spacing is a farce designed to force us to give up habitat. The truth is, there are so many other successful spawning fish between the MPA's, there is no chance that we will ever see a benefit in the overall fishery, vs. a limited success of not removing some of the adult fish inside an MPA. This is not off the cuff, but a series of facts well pointed out and versed by Dr. Ray Hilborn, one of the leads of the SAT for the MLPA.

Finally, someone who understands the need for controls in this experiment that has been poorly designed for us!

This is the very message that was in the video clip that I tried to show on behalf of the CFC at the last BRTF meeting. This was one of the main take home messages in the clip that Ken Wiseman cut short my time to discuss; that these spacing guidelines do not hold much true scientific value - based predominantly on theoretical models and data extrapolation for larval dispersal - in that a whole other team of scientists assigned to come up with guidelines for this process would have probably reached different conclusions and set up different guidelines. Another team could have suggested 6 square miles - or 3. Or 18 minimum.

Point being: the spacing guidelines are pure poppycock.

Originally Posted by ekinoderminator

I can't see why any science would anticipate recruitment to only be successful in an MPA.

why do you think there would have to be NO recruitment from areas outside an MPA for recruitment to have a "spill out" effect from an MPA? It seems obvious to me that there will be varying levels of recruitment all over.

Where I have my biggest problem with the science behind MPA's is that pressure will increase greatly in non MPA areas and some species may suffer as a result.

I share the same thoughts and concerns. Especially regarding the new artificially high pressure on areas that will still allow fishing/extraction.

I like the discussion, guys, thank you!

[So Cal Shaggy]

Originally Posted by Kelsea

the spacing guidelines are pure poppycock.

I like the discussion, guys, thank you!

The spacing guidelines are not the only poppycock being stated by the extreme closure proponents. The "spill over" affect that they keep bringing up is inaccurate as well. The notion that the fish within an MPA will reproduce and populate the area with so many numbers that they will overflow into the surrounding area is poppycock as well. If the fish numbers increase to the point that there is no more room within the MPA they will not exhibit behavior contrary to their instinct. Calico bass are structure oriented fish and do not stray far from rock or kelp habitat therefore if in Laguna they are so dense they will not start moving out to occupy the sand flats that are open to fishing. The reality is that within the MPA the populations will increase as long as the readily available food sources are available. The fish populations will reach a plateau and if there is not sufficient food available within the MPA they will begin to predate the smaller fish of the same species within the MPA and self regulate their populations. Also any mature fish transitioning between MPA's will be fair game for the more condensed fishing pressure in the open areas resulting in less adult fish transitioning between MPA's and if the spacing data was inaccurate when it was studied there will be no larval dispersal into some of the MPA's thus resulting in genetic non diversity.

[ekinoderminator]

I am trying to find a free means of accessing the Hilborn/Worm study....

Biodiversity Loss in the Ocean: How Bad Is It?
Steven Murawski, Richard Methot, Galen Tromble;, Ray W. Hilborn;, John C. Briggs;, Boris Worm, Edward B. Barbier, Nicola Beaumont, J. Emmett Duffy, Carl Folke, Benjamin S. Halpern, Jeremy B. C. Jackson, Heike K. Lotze, Fiorenza Micheli, Stephen R. Palumbi, Enric Sala, Kimberley A. Selkoe, John J. Stachowicz, and Reg Watson
Science 1 June 2007 316: 1281-1284 [DOI: 10.1126/science.316.5829.1281b] (in Letters)
Does anyone have access or know of a free means of accessing it?
Thanks.

[ekinoderminator]

Ray Hilborn and I had a few email exchanges today. Here is what he had to say.....

John:

I don't think there is any question that if a MPA is effectively enforced the species that are sedentary as adults and exploited will be more abundant. I don't think it is a fisheries management issue, but simply one of how many areas do we want with higher abundance. The weight of the evidence is that the sustainable yields will be lower. So society just needs to decide what it wants, more yield or more parks. That is the obvious trade-off that came out of the models used in the MLPA process.

Certainly for the federally managed species I don't see any sustainabilty
concern, the regulatory structure keeps the exploitation rates very low
and I don't see any way that MPAs will increase yields.

The state has not been very forthcomming on the status of state managed
species, so it is harder to tell. For a species that is now and will
continue
to be seriously overharvested then MPAs will contribute to sustainability.

I don't know how long that list is, but it does not include all the
species that that are listed as overfished species by the feds, the
average exploitation rate on those species is now well below 1%.

Ray


the file he sent me exceeds the capacity SB allows - I am happy to email it to anyone and I'll work on getting it on here. It is interesting and relevant.