Reserve Size and Design--What's the Best Option?

Last week, President Obama announced his plans to create a gigantic new Marine Protected Area (MPA) in the Pacific Ocean. This is generally some welcome news, as more Marine Protected Areas will be helpful in preserving marine biodiversity. However, this announcement provides me with the opportunity to talk about some of the problems with what may seem to be relatively straightforward conservation measures. Ecosystems are incredibly complex, and solutions that may seem to be relatively straightforward are not always so.

For starters, let's examine things in the context of terrestrial reserves, because some of the interesting issues of marine reserves that I will get into later in this post do not necessarily apply in a terrestrial context. Let's say you have the budget to protect 100,000 km² of land. Is it better to have a single 100,000 km² preserve? What about 10 10,000 km² reserves? 100 1,000 km² reserves? Some other optimal size?

The first step in determining this is having a clear goal of what you want your reserve to be able to do. Are you looking to protect a particular species? Is there some landscape feature you want to make sure will remain for future generations to enjoy? Are you trying to retain Ecosystem Services (this is a term that refers to what ecosystems can do for people--think of things along the lines of marshes in the Gulf of Mexico buffering against storm surges)? All of these will require different reserve designs.

In a marine environment, things change even more. One of the key differences is that, if you put something in a terrestrial environment, you can expect it to stay where you put it. In a marine environment, this is far from the case. While there certainly are marine environments worthy of protection that are static--reefs, seamounts, kelp forests, et cetera, in the open ocean things are far more dynamic. Resources can move around on currents, and predators can follow prey species great distances looking for dense patches that may last only brief times.

What this means is that, in a marine context, you need to do one of two things: either have truly gigantic reserves so that, by the law of averages, the stuff you're trying to protect will be within the reserve most of the time. The other option, and the road often taken is to, rather than trying to protect a particular area, restrict activities that might otherwise have detrimental effects on conservation targets. This may range from fisheries regulations--seasons, catch limits by biomass, and equipment restrictions, to dumping restrictions and everything in between.

That being said, I am in no way, shape, or form trying to criticize the President's actions. Marine reserves do work. Repeated studies have shown dramatically increased biomass within reserves, and even outside reserves but near their borders. They are so successful that fishing vessels often loiter near the borders of reserves due to increased fish biomass. The point here is that, when it comes to conservation, there are more complex concerns than "protect everything everywhere and that'll be fine".









Papers for consideration:
Halpern, Benjamin S. 2003. The Impact of Marine Reserves: Do Reserves Work and Does Reserve Size Matter? Ecological Applications

W. F. Humphreys and D. J. Kitchener. 1982.The Effect of Habitat Utilization on Species-Area Curves: Implications for Optimal Reserve Area

Journal of Biogeography

About this Blog

Well, to get things started here, who the heck is this blogger guy who's writing this blog? My name is David Savage, and I am (as of time of writing) a very recent graduate of the University of California, Santa Cruz, with a degree in Ecology and Evolutionary Biology. I think science is really cool, and that a lot of ecological concepts can be explained in ways that will make sense to people without a necessarily extensive ecological education, especially through the use of clever metaphors and analogies, which have proven to be an effective tool in science education.

The plan for this blog, at least as of now, is to, each week, take a single ecology-related article, whether it is in a peer-reviewed scientific journal or in the popular press, and break it down and analyze it for general audiences. I'll do my best to choose articles that are not behind a paywall so that, should I end up with any readers, you all will be able to look at my source material. I'll also cite other articles on each post that might be useful, and while my professors would likely be annoyed that I'm not using some formal citation format, I hope to have enough information to satisfy both readers' curiosity and my own sense of ethics.

I will be up-front about this: a large part of my reason for writing this blog is so that I can show it to potential future employers and/or graduate programs. I don't want to be dishonest about that fact, but I hope that this will not turn anybody off of this blog if you might otherwise read it.