Science behind the proposed closures

[flathead_fred]

I don’t claim to be a fisheries biologist, far from it in fact. However I am a 3rd year Science student studying at the Uni of Qld, specialising in Marine Biology/Ecology, and have been a fisherman my whole life. I discovered this website quite a few years ago (see profile), although I have not posted for quite some time, choosing to sit back and absorb the knowledge one can gain from a forum such as this. Finally, an issue very important to me has arisen, as I am both a passionate marine ecologist and fisherman, and I believe my tertiary education can provide somewhat of an insight into the science behind Marine Protected Areas (MPAs) and fisheries biology.

I was lucky enough to travel up to Orpheus Island (Palm Island Group) and work directly with Gary Russ and Richard Evans, who have carried out many surveys of the effects of Marine Park Zoning on the GBR and abroad in the Philippines (two highly influential people in the recent rezoning of the GBRMP as their studies were used as supporting arguments), and have been lectured by the ecologists who have and will be a major part of the MBMP Zoning. It was at Orpheus we looked at the effects of no-fishing zones on Orpheus and Pelorus Islands, and the students which attended got an amazing chance to conduct visual surveys and trapping on the fringing reefs to compare the abundance of Coral Trout (Plectropomus), Stripey (Lutjanid) and other non-targets of the fishery (butterfly fishes (Chaetodon), rabbit fishes (Siganid) etc) in Green and Blue zones. This experience and my ecological background might clear up some issues concerning the closures. I would be happy to email the PDFs and/or abstracts of the references is used in my report for this study which will provide further detail about MPA and their potential use for sustainable fisheries management tools.

To cut to the chase, MPA’s (or no take zones closed to all extractive activities) are quickly gaining popularity worldwide as fisheries management tools, with the North-western Hawaiian Islands National Monument (some of the most undisturbed reefs in the world like that on the GBR) recently overtaking the GBRMP for the largest area of no-take zones. This is largely the result of highly motivated fisheries scientists rasing awareness of the detrimental effects of fishing activities, both past and future, attempting to reach the pinnacle of management strategies, sustainability, by suggesting ways to reach this goal (MPAs). Unfortunately, locking away areas from fishing have not resulted in improvements in the surrounding fisheries, mainly because ecological processes operate and highly unpredictable ways (ask for further detail)(few exceptions exist in the Philippines where there has been a gradient of increased catch rates radiated from no-take zones). To this managers respond with reference to evidence that this zoning has increased the net biomass of the species within the closed areas (shown clearly in the report from my trip up north among many others), which is their primary goal by carrying out the closures and protecting the ecologically significant habitats within. There are hypotheses suggesting a net export of biomass out of these areas through adults and larvae into the surroundings habitats, leading to improved catch rates in the long term (ask for further detail, its pretty interesting stuff). However, these hypotheses have not yet been proven conclusively, but seem plausible, and are the basis for these no-take areas as fisheries management tools. For a logical thinking fisherman, this would obviously rely on the ecology and behaviour of the species (sedentary or mobile), as well as a whole suite of other factors such as larval supply, hydrodynamics, habitat quality etc.

I am not protesting against the zoning, nor am I a mole sent from the AMCS, I am simply providing some background which may be helpful in building a well informed argument. I hope this cleared up any issues as to why they are planning/are going to carry out this re-zoning, and the potential flaws in its implementation. As a final thought, Australia’s fisheries are considered by many to be some of the best managed in the world (W.A. lobster fishery is considered THE BEST by a number of scientists), with many countries following our lead such as America. But are we sacrificing the well being of the people that use these natural resources (especially recreational fisherman who are an very important part of fisheries studies as they provide often unobtainable, detailed information on catch rates, species distributions, diversity and abundance of marine organisms, as you are all well aware…..see previous posts by fellow Ausfishers on how they sneakily used recreational data to close off reefs). I am happy to take any criticism, the science is not perfect, that’s for sure…..and I will go into detail about specifics pertaining to MPA’s and fisheries biology in general if you need any clarification, its difficult to explain even at this length.

Thanks guys,
Mike

P.S. Don’t take my word for it….. Google search Marine Protected Areas

[madmix]

Hi Mike,
I will start by saying that I have very little time for snapshot science,
for instance my work once took me to a remote central Australian
billabong, where quite by chance I got to witness thousands of
pelicans hearding schools of tiny fish into the shallows. This was
a truly once in a lifetime sight, as I rushed back the next day with
camera in hand and not one pelican remained.

Now onto the issue of no take zones, James Cook University has just
released the results of its latest surveys of GBR zones closed in 2004.
They claim that in two years, there has been an increase in the
number of coral trout, in the range of %60. By the way, it is pure
coincidence that they just happen to announce this in the lead up
to closures of the Great Sandy Straights and the Qld election.
This apparent dramatic increase however, is totally against all their
scientificaly based predictions and more importantly is totally out
of line with years of research into no take, conservation and
research zones that were closed a decade earlier.

Cheers Mick

[Jeremy]

Mike,

here is an arguement against the use of no take MPAs as fisheries management tools. The whole article is too long to post here, but can easily be found using a google search or I will email it to anyone who asks.

No Take Marine Protected Areas (nMPAs) as a fishery management
tool, a pragmatic perspective

A Report to the FishAmerica Foundation
By Robert L. Shipp, Ph.D.

Executive Summary

Marine Protected Areas (MPAs) are portions of the marine environment which are protected
from some or all human activity. Often these are proposed as a safeguard against collapse of fish
stocks, although there are numerous other suggested purposes for their establishment. “No take”
MPAs (hereafter referenced as nMPAs) are those from which no harvest is allowed. Other types
include those where certain types of harvest are prohibited, which are reserved for certain user
groups, or which are protected from other human activities such as drilling or dredging.
Establishment of nMPAs may have numerous beneficial purposes. However, as a tool for
fisheries management, where optimal and/or maximum sustainable yield is the objective, nMPAs
are generally not as effective as traditional management measures, and are not appropriate for the
vast majority of marine species. This is because most marine species are far too mobile to remain
within an nMPA and/or are not overfished. For those few species that could receive benefit,
creation of nMPAs would have an adverse effect on optimal management of sympatric forms.
Eight percent of US fish stocks of the Exclusive Economic Zone (EEZ) are reported to be
experiencing overfishing. The finfish stocks included in this number are primarily pelagic or
highly mobile species, movement patterns that don’t lend themselves to benefit from nMPAs.
Thus a very small percentage, something less than 2 %, depending on mobility potentials, is
likely to benefit from creation of these no-take zones. However, many of these species have
come under management within the last decade, employing more traditional fishery management
measures, and are experiencing recovery.
MPAs (both “no take” and other types) can serve a positive function as a management tool in
protecting breeding aggregations, in helping recovery of severely overfished and unmanaged
insular fish populations with little connectivity to adjacent stocks, and in protecting critical
habitat which can be damaged by certain fishing methods.

[Jeremy]

If you are deadset not a mole, then I urge you to go to this link to a thread on this topic in the 'fishing news' section. Particularly pages 10-12, there is a debate about some of these facts. Perhaps you could come back with a counter arguement against some of the arguements put forward by KC and others, if you have a leg to stand on!

http://www.ausfish.com.au/forum/YaBB.cgi?num=1155192328

Jeremy

[DR]

However, these hypotheses have not yet been proven conclusively,

[Glind]

"potential flaws in its implementation" and
"the science is not perfect, that's for sure....."
But if the scientists tell the Government we need a Green zone or a lock out or an MPA, then that is what we will get I'm afraid. To what end?
Oh dear.......
Tim

[rando]

The reports of dramatically improved populations of mature fish in the closed areas seems to be at odds with known growth rates of the surveyed species.

Further if they percentage increase(50% has been quoted) in mature fish proves to be correct, how can the increase be attributed to natural growth when such elements as migration have not been excluded.

You dont have to be a "bush lawyer" to figure out that fish will congregate where they experience the least interference from, boats, divers ,fishing(closed areas)
I am not a scientist , but I can apply reason, and it seems unreasonable to me to accept that such unexpected results should be touted as proof of success of the closed area program.
rando

[Burley_Boy]

Hey Mike,
So to cut to the chase, what would you suggest is a good way to manage our resources and does this include having areas that we can fish in or should we all install our own dams and take up cyberfishing?

Are no take zones a better environmental alternative to an actively used but managed area? Realizing that making one area a no take zone will mean that something will have to come from somewhere else unless we all become vegans.

Just interested in your thoughts and if you do enjoy fishing then what would you like to see happen.

BB

[fish_outta_water]

im not a schooled man(as youll tell from my spelling i expect) but surely mpas can only provide habitat for demersal species? as peligic wont stay still long enough other than to eat all the fish they can get. unless your looking at creating migratory corridors pelegic stocks will be caught as usual
i think these mpa area are equaly driven by the potential tourism factors through dive sites . than for potential "stock" factors

in the uk people have been lobbying to stop pair trawling for sea bass for years (stocks have reached lows), finaly it was outlawed not because stock levels but because the odd porpoise gets caught in the nets. (love em but there not low in stock numbers)
sorry to digress from your topic but wanted to point out the perfectly legit scientific reasoning can go ignored for years , but when the "fluffy bunny" crew get involved ("awwww lookit the poor dolphins") public opinion wins the day... not grumbling as the bass stocks are slowly coming back here would like to see some sense in fishery managment though
tightlines all

[littlejim]

I find it hard to believe that the number of recreational fishermen in Australia can take out enough fish to alter the breeding population. After hearing about amount of fish that the japanese long liners put on the market compared to their quotas I can beleive that professionals can affect the breeding population. The salmon cannery at Eden years ago lend s weight to that, it closed after they wiped out the previously huge schools.
After seeing the areas closed in the Jervis Bay Marine Park you can see that the areas closed aren't necessarily fish nurseries, there are all sorts of other reasons why certain areas are closed that have nothing to do with allowing fish to breed.
Currently the system seems to be somebody with a well-intention 'green' bias says 'I reckon' this area should be closed and subsequently scientific people can try and see if it worked or not. The science doesn't seem to occur first.

If my 'I reckon' was given as much weight as the other 'I reckons' I would spend the dough on creating a heap of artificial reefs rather than stopping the poor old recreational fisherman from going to his favourite spots.
Does anyone know whether there is any research on the tyre reef at Hervey Bay and whether it made much difference to fish number up that way?

[hungry6]

The one thing that will dramatically increase biomass in a marine habitat is Banning of trawlers and netters, not that I'm against commercial fishermans,as they do have a livelihood to lead.
Also, the claim that the science is not proven or perfect. But to my understanding is , it is only SCIENCE, when hypothesis and theories are proven and repeatable results can be achieve within the same conditions.
From what I've read above, all those MPA's are set out by someone or by a small group of individual bases on a gut feeling as far as I'm concern. #
Almost forgot, a scientist should be unbias in his or her views, but from of late and where the fundings comes. I'm sceptical as to how tainted or "doctored" as to the results we are given.
Excuse the pun.

[Great_White]

You can box it up with pretty paper and a lovely ribbon but it's still Sh!T, no matter how you try and dress it up.


Peter.

[flathead_fred]

Thanks guys, I appreciate your comments. I am always amazed at the knowledge this site contains, thanks for you replies. I am by no means supporting this quite inflated figure of 50% no-take zones, I am just trying to give you an insight as to why scientists think MPA’s can be effective. It almost seems as though the science has to catch up with the management strategies which are often far too swift and excessive without any real evidence to support them. I’ve been told many a time by my lecturers that these management strategies are now treated as hypotheses which must be continually tested and must adapt in the presence of new information.

I will quickly summarize the reasoning behind why some believe MPA’s can be effective fisheries tools, which is based on simple population dynamics. By reducing or eliminating fishing pressure, the average size (age distribution shifts to the right as a result of reduced mortality and more individuals reaching the larger size classes) and abundance of the target species will increase (simply a result of reduced mortality). Prey species abundance will obviously decrease within the green zones due to the increase in predation from targets like Coral Trout. The effects on surrounding fisheries are two fold. The spill over of adults results from increased competition within green zones, leading to density-dependant emigration. They are also expected to move out of green zones and exploit the relatively more abundant prey species outside green zones. It has also been proven that larger coral trout produce more eggs, and when coupled with an age distribution shift to larger size classes, no-take zones can act as larval banks to replenish surrounding areas. None of this has been unquestionably proven, it is simply the “expected outcomes” based on hypothesised ecology. This may not apply to pelagic species for obvious reasons. Density-dependant emigration may not apply to highly sedentary species like cod (adult coral trout have been tracked moving many km’s). At the moment, larval supply ecology, including settlement and recruitment patterns, is trying to understand what makes fish, crustaceans, sessile invertebrates etc settle in certain areas, and how highly unpredictable environmental factors can have he consequences for the aforementioned.

Once again I must stress that I do not agree with these closures, I am simply giving you the information which the managers are using justify these seemingly heavy handed strategies. I am not interested in the politics, nor am I in the position to suggest what should be done. There is so much to learn from the marine environment, that why I was determined to go to university and am currently learning about these pressing issues.

Once again thanks for you comments, please continue to rebut as I feel as though I am sometimes at the mercy of my lecturers personal agendas, and don’t often get to see the whole story.

Mike

[hungry6]

Flathead-fred, I'm not questioning your agenda or thoughts, but what I can say. In Australia once a law is legislate or similarly an area is zone as #MPA's. It is then pretty much locked away or set in stone forever, unless it is reverse with the approval by the majority of the house of parliaments.
So the reason why you see so many of us abit archy on this issue, as it is not only a short term thing, but a life long ban.
As a member of the average income scocio group, I can tell you that, fishing is a main form of entertaiment for the average person, as they do not have the money or time to attends theatres/musicals or corporate functions.
So to cut it short, fishing is very important to alot of us, and we want to be able to do it in our own "moreton bay" back yard!!

[flathead_fred]

Very well said hungry6, and I am equally scared to think what will come at the end of this review process. Unfortunately i only get the scientific view most of the time, and need to hear from people like yourslef so that i can understand the issue in its entirety. im just worried this " science" is taken as fact when it is clearly complex and will probably never be fully understood. I am lectured and have been lectured in the past by the very people with which they consult with to implement these zoning plans, and i just think that you all have a right to know how simple and often flawed the science is behind these ill concieved managements strategies. Sustainable develoment (the primary goal of the state coastal management plan) is supposed to consider economic, environmental and social factors, but i find it hard to comprehend how this can be reached with the current planning.

Thanks,
Mike