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Design Placement and Cost of Marine Reserves

November 16, 2010 in Uncategorized

Throughout the world’s oceans fish catches are declining, vast numbers of marine animal populations have been wiped out, while habitats and communities have been irreversibly damaged or destroyed. It’s becoming more evident that marine reserves and marine protected areas (MPA’s), conserve an area’s population and habitats by limiting or preventing human activities in the area, and via ‘spillover’, can sustain, replenish or even increase biomass of nearby fisheries, nullifying the fisheries initial losses when the MPA or reserve was created. Increased efforts are now being focused on identifying key areas and creating the most successful configurations.

Short term

From the initial proposition of the creation of a marine reserve there is need to please multiple and opposing schools of thought on the subject. The greatest opposition against the creation of a reserve usually come’s from fishermen. Fishermen tend to focus on the short term consequences of creating a reserve, this is the period just after the reserves creation, in which the fishermen but not the fish stocks, have time to respond (1). Their main concern is the reduction of fishing ground and fish stocks accessible to them (3). However the intensity of this opposition varies greatly depending on multiple factors.

The main factor in altering the fishermen’s opposition and their willingness to pay (WTP), is the fish stocks in the area. When the proposed reserve sights have a high fish biomass in comparison to the surrounding area and fishing sites, opposition is high. However highly skilled fishermen tend to oppose the creation of a reserve more so than low skilled fishermen, and this is then reversed when the reserve contains lower fish stocks than the surrounding waters (1). Low and high skill fisherman only have similar views on WTP when fish stocks are equal, though all of these views can be magnified depending on the fish prices at the time (1).

The creation of a reserve always reduces short term income for fisheries, however high wages outside of the fishery reduces the opposition to reserves in both the short and long term (1,3). If wages are high outside the fishery fishermen are more likely to leave, this reduces the pressure on stocks and lessens the fishing effort. This is better for conservation efforts, but also can be good for fishermen due to a reduction in competition. This means that reserves should be easier to set up in areas with high non-fishery job opportunities. Fuel costs also alter opposition in a similar way to job opportunities.

There is also the social sciences side of the fishermen’s opposition. If they value the fishing lifestyle what the site would be worth to them would increase. It’s been found that strong emotional attachment has similar effects to having a low non-fishery wage, family life, the fishing culture and relationships with friends will also have similar effects (1,11).

Long term

The main arguments of scientists and researchers is to look towards the long term factors that can benefit all, though fishermen are usually more reluctant to embrace this view. Scientists want to provide the species the best opportunity to repopulate, however they have to plan for spillover effects, and find a balance between conserving a species by reducing spillover and maximizing spillover to rebuild surrounding populations and replenish the surrounding fisheries (2,5,6,8).

Studies show that creating singular reserves to protect a species, the reserve must be the average larval and adult dispersal distance without input from alternate sources. However this can be upto ten’s or hundreds of kilometers (7,8), few are able to create reserves this large and very few have (5,12). Alternatively, a number of countries have created networks of marine reserves (5). Combining multiple smaller reserves can provide a greater impact (4), these multiple linked reserves maximize larval exports to other reserves increasing the likely hood of being self sustaining. Networks can also be used to protect multiple habitats due to a species movement and different habitats used throughout their life.

When placing a reserve it has to be kept in mind what stage of the species needs to be protected, throughout a species life it may move to differing habitats depending on its stage of life (5,7). Using a network of marine reserves rather than one large one, reserve’s can cover multiple habitats possibly protecting a species throughout its life (5,8), or a network can be used to protect a whole ecosystem from damage and natural disasters by acting as back up reserves to help replenish any damaged by a natural disaster (5).

Protecting spawning grounds will benefit any species (5). However while it may be one of the few ways reserves can protect long range pelagic fish (billfish, tuna and oceanic sharks), low to medium range fish spillover can reduce the number of spawning adults enough so that the reserves larval input isn’t enough for it to sustain itself or help maintain surrounding waters (5). Fish with a lower range benefit more from a network than pelagic fish because of inter-reserve dispersal, this will further protect fish from nearby fisheries and increase larval dispersal between reserves (5,7-9). Maximizing larval dispersal is a key design in reserves, this is because when larvae leave reserves they are too small to be caught and are relatively unaffected by human input (excluding pollution), they can successfully move to another reserve were they can survive to adulthood just as easily as in their natal reserve, however by leaving the reserve as adult fish are they are then at risk of becoming part of nearby fisheries (5,12).

Having a network of reserves also benefit fisheries by maximizing spillover. Spillover is a side effect of a prospering reserve or having a reserve protecting a high traveling species, its where an increase of biomass inside a reserve spills over and increases the biomass of species outside the reserve (2,4-10,12). Though spillover can have damaging effects on the reserve, if too many adults are leaving the reserve and getting caught, this will reduce the number of spawning adults and leave the reserve unsustainable (5). Spillover is not just a damaging effect, a successful reserve can replenish surrounding fisheries and used in a network of reserves can increase diversity and sustainability, via dispersal of larvae (2,4-9,12).

Networks can also be used to benefit fishermen as well, by decreasing the distance between fishing areas, increasing the edges of reserves and the amount of reserve edges, increases a fisheries access to spillover and by reducing the distance between them save’s on fuel from not traveling long distances between fisheries (1,5). When designing boundaries of a reserve, placing them on the edge of a habitat boundary such as a reef edge will protect and help contain the species in the reserve conserve them by reducing spillover, however placing a reserve boundary mid habitat will increase spillover and increase benefits for fisheries (5,9,12). The overall location can benefit fisheries as well, through placing reserves by ports or easy access points, this minimizes the cost of travel to the site. Usually areas near access points are the first to be over exploited and are usually the areas most in need of protection. However when spillover is not expected it’s better to set up reserves further away from ports to reduce fishing around it, maximize conservation and to increase the cost to get there which decreases profitability and interest in fishing the site (5). When designing a marine reserve there is a need to find a balance between conservation and spillover. A rule of thumb for reserves is that they both receive and contribute sufficient larvae to other reserves, without this the fate of a reserve is tied to surrounding fisheries, a way to increase this likely hood is to create networks (5).

If a successful balance has been found in the reserve network between spillover and conservation fisheries WTP will decrease over time and can even reach the point where fisheries are paying for the creation of a reserve, or negative WTP (1). However at a reserves creation it can be predicted, but there is no way to know which one of three scenarios that reserve will take in the amount of spillover created. Scenario One; in the network all the reserves are closed systems, all sites are self sufficient and give no output or input, as if the area was walled off. In this closed system opposition rises steadily with time (1). Scenario Two; the source sink, this is were the reserve is a source or breeding ground for a species (1,4,5). The general trend is for the opposition to initially increase (5 years) but then declines and begins to level out over time (20 years). Over this period the surrounding populations initially decrease due to the shift in fishing effort to other waters, but over time with dispersal from the source sink system the population will recover via spillover (this may also be helped by an abundance of jobs outside of the fishery) (1). Scenario Three; is the relative density dispersal system, this has an outcome in-between the previous scenarios, there are spillovers but not less than in the source sink system. Opposition in this scenario is similar to the source sink system, it increases then steadily decreases, however the decrease is usually longer, and there is less chance of negative WTP (1).

WTP is also affected by the number of boats allowed into the reserve, in certain reserves limited numbers of vessels are allowed for recreational and subsistence fishing and fishing with less destructive gear (6). Within a closed system a greater number of boats reduces the difference between short and long term opposition. A high number of boats in a closed system defeats the object of a reserve because stocks will be heavily fished, some boats will leave to non-reserve sites due to the formation of the reserve furthering the degradation of the surrounding stocks. While allowing too few boats into the reserve, the reserve is underutilized and opposition is reduced (1). In a source sink system varying the number of vessels can create large long term benefits, but with varying costs in the short term. If the number of vessels in the source sink system are too high the reserve becomes overexploited, but the reserves dispersal benefits are greater than the losses in the closed system in the long run (1).

Problems in reserve design

However, despite all of this if marine reserves and MPA’s are to become more widespread there are multiple issues and challenges that need to be addressed. First, with the huge biological diversity in marine ecosystems no reserve can benefit all, although some basic rules are appearing that may maximize benefits for more species. Focus is now being placed upon increasing the range of species that are benefiting and reducing the gap between how much different species benefit (4,5). Although, if species are benefiting more than others how will this affect their interactions?  (5,12)

Furthermore, reserves are being created on todays biological and physical conditions, theses features are often climate linked. Marine reserves are immobile, but as the climate and ecosystem shift so too will the species they are designed to protect (5,12). In addition, larval development time are effected by temperature, are the marine reserves of today focused on profitability going to provide the same in an altered ecosystem? (5). Moreover, network design has been focused on maximizing and reaching profit and yield goals for fisheries. Networks of reserves could also be used to reach other fishery goals such as estimating the effects fishing has on the ecosystem for the ecosystem-based fisheries management, stock assessments and separating the effects of fishing from climate change and other effects (3,5,8,12).

Fourthly, the success of these designs remain largely untested, with existing networks only just reaching long term existence and an increase in the creation of new networks, data on their success is relatively sparse and only now can scientists see whether theoretical models work(2,5). Lastly, more data is needed on the costs of establishing and running a reserve. It’s been predicted that to sufficiently protect the earth’s waters 30% must be either a reserve or an MPA, though 20% has been seen as more of a reachable target, it is unknown if anywhere near this target can be afforded (2).


  1. Martin D. Smith, John Lynham, James N. Sanchirico, and James A. Wilson (2004). Political economy of marine reserves: Understanding the role of opportunity costs. PNAS January 19, 2010, doi: 10.1073/pnas.0907365107. <>
  2. Andrew Balmford, Pippa Gravestock, Neal Hockley, Colin J. McClean, and Callum M. Roberts (2004). The worldwide costs of marine protected areas. PNAS June 17, 2004, doi: 10.1073/pnas.0403239101 <>
  3. Quach Thi Khanh Ngoc (2010).  Creation of Marine Reserves and incentives for Biodiversity Conservation. Bioecon 12th 2010. <> fishermen need benefits
  4. Lars A. Brudvig, Ellen I. Damschen, Joshua J. Tewksbury, Nick M. Haddad and Douglas J. Levey (2009). Landscape connectivity promotes plant biodiversity spillover into non-target habitats. PNAS May 22, 2009, doi: 10.1073/pnas.080965810. <>  spillover high fish catches
  5. Steven D. Gaines, Crow White, Mark H. Carr, and Stephen R. Palumbi (2010).Designing marine reserve networks for both conservation and fisheries management. PNAS March 3, 2010, DOI: 10.1073/pnas.0906473107. <> tab 7 the ultimate
  6. Sarah E. Lester, Benjamin S. Halpern (2009). Biological responses in marine no-take reserves versus partially protected areas. Inter-Research science centre, Sep 11, 2009 <> opposition fishers short,
  7. Amitabh Avasthi (2005). Ecosystem Management: California Tries to Connect Its Scattered Marine Reserves. Science 22 April 2005: Vol. 308. no. 5721, pp. 487 – 488 DOI: 10.1126/science.308.5721.487. <>
  8. Louis W. Botsford, Foirenza Micheli, and Alan Hastings (2003). Principles for the Design of Marine Reserves. The Ecological Society of America, Applications, 13 Supplement, 2003, pp. S25–S31, 2003. < 10.1890/1051-0761%282003%29013%5B0025%3APFTDOM%5D2.0.CO%3B2>     not sure
  9. Callum M. Roberts, James A. Bohnsack, Fiona Gell, Julie P. Hawkins, Renata Goodridge (2001). Effects of Marine Reserves on Adjacent Fisheries. Science, 30 November 2001:Vol. 294. no. 5548, pp. 1920 – 1923 DOI: 10.1126/science.294.5548.1920. <>
  10. Benjamin S. Halpern, Robert R. Warner (2002). Marine reserves have rapid and lasting effects. Wiley online library, Article first published online: 17 May 2002 DOI: 10.1046/j.1461-0248.2002.00326.x. <>
  11. Kenneth Broad, and James N. Sanchirico (2008). Local perspectives on marine reserve creation in the Bahamas. SciVerse, Science Direct, Volume 51, Issue 11, 2008, Pages 763-771, DOI;10.1016/j.ocecoaman.2008.07.006 <>
  12. Alan Hastings, and Louis W. Bedford (2003). Comparing Designs of Marrine Reserves for Fisheries and for Biodiversity. Ecological Society of America, Ecological Applications, 13 Supplement, 2003, pp. S65–S70 2003 <>

Marine Reserves as linked social-ecological systems

November 15, 2010 in Articles 2010-11

Figure 1 Showing the human effects on a food web before and after

Marine reserves are areas of ocean which are protected by law that prohibits any extractive activities such as fishing in order to preserve the marine ecosystems. Reserves are usually located in coastal areas near areas of large extractive activates. The importance of marine reserves only recently became apparent in the last few decades as fishing technology advanced to a point where by no part of the ocean was unfishable. When reserves were formed on previously highly fished areas it became obvious in just a few years how positive of an impact these areas can have. With no fishing allowed organisms were able to grow too much larger sizes, for fish this led to greater populations because the larger the females grow the amount of eggs they can release grows exponentially. Then with this increase in population it causes an ‘over spilling effect’ where by fish become too overcrowded and competition is made to high so they migrate out the marine reserves. This creates a constant supply of fish which fisheries can exploit without reducing the average size of any one species. However this fishing has to be sustainable i.e. not industrial trawling ships Fre 1 shows the impacts that people have on the complex food webs within marine environments which reserves attempt to reduce.

Some marine reserves are more effective than others and this may be due to the ecological variables of the area; as well as the socioeconomic views from the coastal colonies living within the reserves. This relationship has been explored on various occasions (however I will be focusing on the research carried out via Richard Pollnac et al. 2010). This research was carried out on 56 marine reserves in the Philippines, Caribbean and Western Indian Ocean. The ecological performance was compared by looking at the target fish biomass (which is the mass per unit area of fish that are exploited by fisherman living in a reef ecosystem). However this data is made relative to the outside of the reserve in order to give a better comparison and this is done by using the logged response ratio or InRR= in(inside/outside). Where by the inside and outside units is the mean fish biomass of each area. The outside areas that are measured are always close to the reserve on a similar habitat so to try and reduce variability of ecosystems.

Figure 2 Showing human environmental impacts on ecosystems

Socioeconomic variables were also taken into account in order to see whether there were any implications that affected fish biomass inside and outside the reserves. The variables taken account were the human population density of the coastal areas within the reserve and the compliance with the rules of the reserve. It has been usually suspected that reserves with higher or increasing population densities would show a negative ratio of fish biomass inside the reserve, as shown in figure one that shows just some of the implications of increasing human density in the surrounding communities. It was found however that it is area specific because the Caribbean was the only place to show this. This is because it was found that increasing population density had a negative effect in the Caribbean, a positive effect in the Western Indian Ocean and a non detectable effect in the Philippines implying that there were more variables than simply human density involved. One explanation given for the positive effect in the Western Indian Ocean is that people migrated around the reserve area due to the success of the reserve. This gave better fishing grounds around the reserve so drawing more fishermen to fish there. This over time dramatically reduced the fish biomass around the reserve so giving the relative positive result. This is one of the disadvantages with the data collecting method that the results can be shown to be positive but in fact the fish biomass as a whole could have decreased. For the Philippines it was later found that there had been very little change in population density so making it hard to make a clear cut relationship.

The more obedient the local government is with the reserves’ rules usually imply that there is a relatively higher fish biomass due to the strict lack of fishing and other extractive activities.However this was only found to betrue for the Caribbean as there was no effect in the Philippines and Western Indian Ocean. This may be due to the different ways in how each reserve is run. During the collection of data they foundthat the enforcement of the rules wasn’t as simple as first imagined. It was found that in fact the enforcement worked through a string of complex social interactions. This was more deeply looked into in a study concerning 127 marine reserves whilst looking at the contextual conditions of each reserve to determine if there was any correlation between social, cultural, political, economic conditions and the way the resources in the reserve are managed.   As seen in figure 3 enforcement is indirectly related to compliance where as the monitoring by the community and advisors is more directly related so in order for a reserve to be successful governments need to be investing in these indirect processes to ensure that the compliance increases.

Figure 3 Showing a Heuristic model between socieconomic consitions and compliance

Monitoring reserves from all around the world can be difficult because of the idiosyncratic methods that each area employs to track the progress of the reserve. Each therefore may give rise to different variables that another reserve may not have such as an unknown environmental factor which can affect the reserve’s performance. That’s why this research was carried out over across the entire social-economic gradient in order to give representation from all forms of economic regions and see how that effected a reserves resources.

Even though the focus of the research was on socioeconomic conditions and compliance other variables were taken into account. The boundary markers need to be placed strategically. This is because they are more than merely boundaries to the reserves; they have to be placed in an area where by a buffer zone can be set up around it. A buffer zone is the area around the reserve that has a socio-economic climate that is compatible to ensure the long term survival of the reserve. Marine reserves are much less common than land ones which is leading to Greenpeace campaigning for 40% of the oceans to be protected. The protection of migration paths and reproductive areas would lead to much better reproductive periods so increasing the marine animal’s populations, which would in turn improve the fishing industries productivity.

The reserve size and age are also good indicators to how successful a reserve is. This is because there it takes time for the effects of protection to be seen, this time is usually just a few years. A good example of this is a marine reserve in a New Zealand that over time went from bare rock environments covered with sea urchins to kelp forests in just 4 years. The size of the reserve can be a good indication because the larger the protected area, the more varying habitats are protected so giving protection to a wider range of species. The larger reserves also give rise to larger ‘over-spilling’ effects n the surrounding seas.

As seen in figure 4 the environmental impacts of human activities have impacted almost all parts of the ocean in some form. The most polluted areas are those in highly populated coastal areas such as the Caribbean, Japan and the UK. This is most likely one of the contributing factors leading to the fish biomass being negative in some of the Caribbean. If the oceans aren’t given the time to recover they may never return to the once bountiful and wide biodiversity that is already being lost in many parts of the oceans. Governments around the world need to employ more permanent means in protecting the oceans but like the areas researched the local participation is vital. This is because the compliance was measured through responses of resource users to see whether supplies were affected at all. This however was found to be bias in some areas in order to protect the resource areas they were exploiting so to take advantage of what resources were left.

Figure 4 Showing Global environmental impacts on the oceans

There will always be instances where by reserves can be totally destroyed due to freak accidents such as natural disasters or oil spills. However the rise in CO2 in the atmosphere will cause large scale bleaching of the oceans coral reefs which would lead to the biodiversity being greatly lowered. Bleaching occurs when the photosynthesising zooxanthellae leave the calcareous coral backbone due to the change in acidity in the oceans (due to he dissolved CO2 from the atmosphere making the waters more alkali). However this is just a defence mechanism corals employ during times of change in order to select zooxanthellae with more alkali environmental limits. However this can take a lot of time for the right type of zooxanthellae to come along so potentially leaving a habitat dead for many years.

There have been many examples where by the rules of reserves have been ignored such as in 2004 during the fisherman protests in the Galapagos islands. These protests were ended peacefully but not until many half promises were made allowing the regulations of fishing to be weakened that were carefully balanced in 1998. This allowed for Fishermans quarters to be increased meaning more fish could be caught in the reserve. This was stopped later in the year however due to many complaints about the changes in the regulations.  Whaling is another good example where by an industry, which in this case is a huge multibillion dollar industry, is unsustainably ridding the oceans of a vital part of food chains which has huge knock on effects down the niche. One of the most worrying facts is that it is estimated that 90% of all shark populations have been wiped out and at rates like this it has never been more evident that a sustainable option has to be made before the resource is gone forever.

“How is the ecological performance of marine reserves related to socio-economic conditions in neighbouring coastal communities” and “What social economic and contextual factors are related to high levels of compliance with reserve rules” were the main research questions explored. All three areas showed negative and positive results but the overall trend was that there was a higher fish biomass relative to outside the reserve with a 95% confidence. When it came to predicting the relationships between regions it was found that population density and stated compliance are the best forms of comparison. The success of marine reserves is undeniable and the push for more marine reserves to be set up is underway; however these are not just to be set up around coastal areas but in large areas of Open Ocean were the majority of the damage is occurring.


Figure References