Sunday, 27 May 2012

Marine Protected Areas ~ Pleasing both conservational and fishing perspectives.

So here I am, yet again, blogging my revision notes in sheer desperation that something will stick in my mind. All I want to do is sit outside and soak up the sun’s rays with a beer (or Pimms) in hand, my friends, my man and some happy summer music. I’ve tried to sit outside and revise, of course I have, but there’s something so very tiring about having the sun on your head all day. Alas, I’ve moved inside… Again.

What have I got in store today then? I’m still on Protected Areas (my exam is tomorrow, oh I need a miracle) and whilst I know I could probably write an okay answer (as in, I’ll be able to muster up some information at least), none of the information that I’m trying to absorb is actually going in.

I’m fairly confident that a question will arise to do with the design of protected areas (or maybe the allocation) and what factors need to be considered in this process. There’s bound to be something although a question didn’t crop up on last year’s exam. I wonder. I made a note on the lecture material that I swore the lecturer had said there is bound to be a question on the design process so, if there isn’t, I’m probably screwed. Anyway…

(Image sourced from:

Marine Protected Areas ~ Pleasing both conservational and fishing perspectives.

One of the biggest worries concerning conservation managers is probably how big a protected area needs to be. Of course, from a purely conservational approach you’d expect “as big as possible” which is essentially to backing perspective for Pew Environmental Group (and other such foundations). Based on the Species-Area relationship, a larger area of land (or sea) will encompass a larger proportion of species and thus would be the best provider of conservation for meeting those conservation targets set. Concurrent to this, a larger area of protection is likely to encompass great habitat heterogeneity which studies have established has a positive effect on species richness. All in all, it seems like the better option doesn’t it? Have a large protected area and you run a greater chance of meeting those targets.

Unfortunately, as I’m sure you are aware from my last blog post, bigger isn’t necessarily better. Yes larger areas can support more species and have greater habitat diversity, but what about those socio-economic factors that are likely to limit the maximum size extent of these areas. Stakeholder support is a huge element of designing and implementing protected areas that cannot be ignored, without their support (either through economic backing or compliance) the viability of protected areas is likely to fall through. Fishermen, for example, solely depend on fish stocks and the harvesting of such for their well-being. Establishing a marine reserve, a protected area that does not permit any fishing activity whatsoever, therefore displaces these fishermen into alternate areas or preventing them from reaping the benefits of decent fish aggregations. Unless you combine both conservation and fisheries management to create a protected area that makes both parties happy, you’re going to get very little support from these fishermen which can simply reduce the area’s effectiveness due to lack of compliance.

The benefits of marine reserves on adjacent fishing grounds has already been well established through various studies; an increase in biomass, abundance, density, size and species richness is expected with reserves. Halpern assessed the extent these in detail using a myriad of studies in 2003; there was an average increase in abundance by 63%, size by 80%, biomass (a greater indicator of species recovery) by 90% and species richness by 59%. This is excellent news for both conservational and fishery objectives. It is generally well-accepted trait that larger fish have a greater fecundity and produce more eggs and engage in more reproductive activities. A 10kg red snapper, for example, produces 20-fold more eggs than, say, 10 individuals weighing 1kg each. This pattern of increased fecundity has been exhibited in Mombasa Marine National Park, Kenya (paper by Rodwell et al. 2002) with a greater biomass of reproductive individuals within the reserve boundaries.

So, what does this mean for the fishermen? It means they can obtain much greater catches just outside of the boundary therefore everyone is happy. This is termed the spillover effect, whereby the benefits observed within the reserve ‘spill-over’ into adjacent waters, either by the movement of juveniles and adults to external waters or the export of pelagic eggs and larvae. In Mombasa fish traps close to the marine reserve boundaries exhibited a 3X greater increase in catch (despite the greater trap density). A similar story also occurred in St Lucia! The downside to this is it does take a while for the benefits to be seen, as with anything. Fishermen, like politicians, want their results there and then and I don’t blame them, at the end of the day their jobs are affected. It largely depends on the extent of damage that areas has endured, but good responses (i.e. doubled or tripled populations) can be expected within 3-5 years.

Going back to what was said earlier about size, the extent of the spillover effect is proportionate to the edge of the protected area. The probability of fish leaving the given reserve is all dependent on the amount of ‘edge’ the reserve has. So, whilst larger reserves are much better from a conservational perspective, from a fishing perspective they offer very little (since the chance of a fish leaving the area is much slimmer) and less likely to be supported. What constitutes as ‘too large’ depends on the mobility of the species within the reserve and also the local oceanographic conditions (i.e. current speed and habitat type will contribute to the extent of a species’ propagule dispersal abilities).

It’s a difficulty faced by those who design protected areas. The initial ‘protect or don’t protect’ is hindered by a multitude of other factors that may cross one of the areas proposed off of the list. Protecting areas that are already heavily impacted by humans, or areas that are consistently affected by natural disasters means that it is likely these effects are going to infiltrate the reserve boundaries. If so, then a much larger reserve is required otherwise species extinctions and extirpations are likely to occur. This then runs the risk of placing all your eggs into one basket – what happens when the whole reserve is affected by an external threat? What then?

Even after the protected area has been implemented, boundaries have been decided and stakeholders are on board, who is going to manage the area? Is it small enough to be managed by the local population – this has proven to be useful in various studies, but when the issues become too severe it requires regional or even global management, but is this to be from centralised governments or from non-governmental organisations? It is nigh impossible to choose a strategy that can fit every scenario because, in simple terms, one size does not fit all.

I think I’ve gone off on one there, but hopefully it is of some use to those who are interested and plus, it serves me well for my exams. I just now hope that a question relating to this comes up!

References for those papers cited:

Rodwell, L. D., Barbier, E. B., Roberts, C. M. and McClanahan, T. R. (2002) A bioeconomic analysis of tropical marine reserves-fishery linkages : Mombasa Marine National Park. Natural Resource Modeling, 15, 183-197.

Halpern, B. (2003) The impact of marine reserves: Do reserves work and does reserve size matter? Ecological Applications, 13, 117-137.


  1. Hi Rachel,
    Good article. I'm sure you'll do well with your exam. I can't help but notice though, your vision seems to be painted with a bit of a narrow brush. I expect this is due to bias/myopic influences of your professor. It's very critical to research data outside of the scope of your courses; explore what findings present from different sources.

    For example, it is a fact that protected areas are a benefit (logic). As you explore in your article here, there are a plethora of variables. It is found (here in California) that reserve size is irrelevant due to the variance in size and diversity of 'micro-systems.' Some ecosystems are measured in square feet while others in acres. When you bring fishermen into the equation (which have been for 100k yrs) we find that fishing pressure an the boarders of these reserves multiplies and negates any 'spillover'. Professor Ray Hilborn U.W. fisheries expert, explains this very comprehensively. What you end up with is an 'island' affect.

    It is also important to note the dynamic nature of the ocean. MPA's can become ineffective and obsolete in the sense that cycles create constant change and mpa's are inherently geared towards a static environment.

    I'm glad to see young people pursuing their passion. But, to be effective in your future, you must explore outside of the box(your professor) you are studying in. I apologize for not having the cite to the Hilborn data I'm referring to, at hand. Best of luck on your test, you'll do great!!

    I'm an urchin diver in California. I have many years of first hand observations of mpa's underwater and years of studying research on this subject.
    Best, Jeff Crumley

    1. Hi Jeff,
      Forgive my brief reply - I've got myself up a little earlier than norm to cram before the exam. Reading over my post I agree with you 100%, I've kind of approached the subject through rose-tinted glasses and not really focused on managing fishing activity per se, just the placement of marine reserves which, as we all know, without effective management and legislative backing is deemed ineffective - a 'paper park'.

      Hilborn is a legend and I really do need to read his paper on this. I actually attended the 6th World Fisheries Congress in Edinburgh (May) as a volunteer and I managed to listen to one of his lectures. It was regarding the importance of using fish as our main protein source and it is the only way we will feed the ever-increasing population (etc, I didn't explain it very well...)

      Regarding the Cali reserves, is fishing activity solely concentrated at the borders and, by negating any spillover effect, are they essentially overfishing the borders still? I can't believe I didn't mention it in the article that the spillover of adult/juvenile recruits does largely depend on the external conditions also. For example, if the habitat outside of the reserve boundary is seriously impoverished or modified by human activity then these reserves act as habitat islands (within a highly modified habitat matrix)... If the borders are being overfishing then the rate of extraction is still going to exceed migration out of the 'island' (Ah, MacArthur & Wilson's theory of island biogeography cropping up here).

      Okay, I've rambled (again). It should be my middle name for sure.

      Thank you very much for your insight, I really appreciate it and I'm sorry that my information came across as pretty narrow-minded. When I have more time I'll treat these posts as mini-projects and try to muster up as much information (from all sources) as I can.


  2. Wow, your the kind of marine biologist we need out there. If you can keep your mind thinking for yourself, you'll be up there next to Ray.

    I checked your profile before I responded the first time. I was actually testing you, or should I say, your professor.

    We have a unique ecosystem here in California; a unique political system, too. For obvious reasons, science, politics and religion must be kept on their own plates. This line is getting blurred in fishery management and brings out guys like me. LOL.

    We've just implemented a new marine reserve system here. It's a mess, 163 existing reserves (state & federal) were converted into a 'chain' of reserves, preparing for the national ocean policy and spacial planning. We also have regulations on marine mammals (otters) involving the endangered species act and MMPA.

    This is where things get sticky. There is an entire war going on and I'm in the middle of it. Some ENGO's are polluting sound science and facilitating junk science. You'll prob see or hear about this, if you haven't already.

    Most of the fishermen in Ca. are well educated on their subject - that we study during foul weather and closed days. I'm very reactionary due to the flawed process and some of our biologists contradicting themselves. Only to find out later, where their grants originated. (I, too can ramble;) )

    Ray Hilborn is very approachable. Our guys work with him all the time. He even did a paper for us. The dude's incredibly grounded and balanced.

    I'll go find some stuff and post it later in the week. My wife is hounding me to get off the machine. (Holiday)

    I'm very impressed with your response and I hope you keep your own mind and direction. Hilborn would be proud of you.

    Best regards, Jeff.

    1. Hi again Jeff,

      Thank you very much for your reply - I'm flattered! I know I'm only young and have a long way to go before I can actually make a difference, but I'm just sick of the system how it is now.

      That's quite an interesting situation that you have in Cali - I'm quite oblivious to what is going on over the pond (not ignorant, just not aware of) so it's nice to hear from another perspective etc. What has happened with the reserves?

      I actually registered Ray at the Fisheries Congress, I was a little embarrassed because I needed to direct him to another desk... He was a lovely man though! Very down to earth, and I really did enjoy his talk.

      Hope you're well! I'm enjoying a well deserved day (or afternoon) off from the rather hectic week of exams.


  3. And all of this assumes that the designed reserves are effectively and actively managed... Without active management and enforcement, there is no way to be sure that the reserve is no-take in reality.

    1. Exactly, we need to up the monitoring, control and surveillance of states that implement NTZ and ensure that people are abiding by the rules. Unfortunately, you'll always get those that do poach within the boundaries. IUU fishing really aggravates me (I did a group seminar with my course-mates on the management of IUU fishing), but then in a lot of cases... Why shouldn't they? The punishment NEVER matches the crime. Take the Scottish fish scam... They were collectively fined £1 million (in the region of, anyway) and I think they had to pay back 'a little' of their profits, but it was still a £63 million scam. How they think that such a small penalty can act as a deterrent I do not know. Off-topic but still relatable right?

      You can't force people to comply, of course you can't, but you can educate them and make them aware of the consequences if they don't comply, or up your prosecutions, give more people/wardens the power to prosecute and hope for the best.

      Every little helps!

  4. Part 1 of 3 (see all three)

    Food for Thought...

    Your starting to see the complex nature of fishery management. Over management, or draconian enforcement doesn't work in any subject. It only creates division and resentment. The key is education. Poverty & greed are the motivators of poaching/overfishing (and, I use the word overfishing reluctantly).

    The line between science and politics must be well defined. It has become blurred.

    Best of luck on your future, Rachel. Stay free thinking and and seek a balance in all the rhetoric you'll swim through.

  5. Aww jeeze!! I messed that up!!

    See all three parts. This is part #1...