Size Matters
When establishing a protected area, one of the
main concerns is size. Which is more beneficial? Having one large protected
area, or a few smaller ones relatively close to each other? Diversity,
population size, disease, and available resources are just a few of the factors
to be taken into account. This recent study conducted by affiliates of Georgia
Institute of Technology on marine protected areas in the Fiji Islands shows
just how difficult it is to determine the “ideal” size for protected areas.
Acanthaster sea stars are a natural part of
the tropical Pacific environment. The sea stars feed on coral and large
populations can quickly degrade coral reefs in a matter of weeks. They have
become a problem for coral conservation efforts in the Pacific. Earlier studies
showed the large-scale protected areas diminished sea star threats. However, the
researchers from Georgia Institute of Technology found that small,
community-based protected areas may be especially vulnerable to attack.
Mark Hay, a professor at Georgia Institute of
Technology theorizes that the degraded areas surrounding the protected areas
allows hiding places for juvenile sea stars. Once the sea stars reach a certain
size and their poisonous protective spines grow in, they may move into areas
with higher coral density. He worries that, “…once these marine protected areas
are successful, they attract the sea stars which can make the small marine
protected areas victims of their own success."
The Fijian protected areas a relatively small—averaging
less than a square kilometer. But while they may be ineffective at protecting
against the sea stars, their smaller size could be a advantage in controlling
the pest. Hay suggests teams of local residents capturing the predators in
periodic harvests to keep populations at lower densities. For these efforts,
the smaller size of the protected areas could allow for more accessibility.
Source: https://www.sciencedaily.com/releases/2017/02/170206155942.htm
Image: Cody Clements, https://www.sciencedaily.com/releases/2017/02/170206155942.htm
Post by: Haley Huang (1)
In theory, deciding which areas to protect seems pretty simple. However, it is easy to forget about all the other threats that could come from places outside the protected area and cause issues. I never realized that it might be a really difficult decision and scientists need to make sure they take all aspects into consideration when debating the size of a protected area. It is interesting that the large-scale protected sites seems to work, but the smaller areas are being attacked by sea stars. There are definitely pros and cons to larger and smaller areas of protection, and in some cases it might be very difficult to pick which would work better. I wonder if scientists will expand the size of the protected area in the Fijian islands, or decide to keep it small because of the other advantages it has.
ReplyDeletePosted by Jordan Milone
You’re right! Lots of times when I hear people criticizing conservationists or policy makers for some decision about a protected area or course of action, I feel that they don’t realize all the aspects that go into consideration, and that while there may be some negative results to the actions taken, that it’s usually done with the greater good in mind. For example, in the case of these marine reserves, the protected areas have a fishing ban, which means the locals can’t source fish from these areas. While it might be better for the coral and fish populations to make the reserves bigger, it just may not be economically sustainable. Having relatively smaller areas would allow for places where local fishermen can keep up their trade, but also allows some areas to remain undisturbed so that coral can recover, which in turn benefits the areas still being utilized as well in terms of fish populations. And as the researcher mentioned in the article, the smaller size could make it easier for locals to remove the pests without too much disturbance to the protected area.
DeletePosted by Haley Huang
I agree with Jordan that in theory creating a protected area should seem easy. Unfortunately there are many factors to consider when it comes to doing so. It sounds like keeping the size of the protected areas small could be beneficial if they have local teams capturing the sea stars. Since this would keep the populations low, that could allow the coral a chance to survive. If they switched to larger protection areas that would probably make it more difficult to capture the sea stars. It is interesting to read about the different efforts that going into trying to protect one species from another.
ReplyDeletePosted by Hannah Jordan
The article mentions that the sea star “outbreaks” are normal and happen regularly in nature, but it’s because of the relatively small size of the reserves that they coral is in danger. However, a larger reserve might not just be economically sustainable, since local fishermen need to fish from the area as well. I’m sure that researchers have made sure that the reserve sizes can sustain an decent population size or allow for a good amount of coral recovery, but I wonder what the ideal size for a reserve like this would be if locals did not need some of the areas for resources. I want to guess that they would make the reserves bigger, though like you said, keeping the size small could be beneficial if they have local teams out there removing the sea stars.
DeletePosted by Haley Huang
I never would have considered that having a protected area that is too large would leave possible harsh effects. It makes sense that having a smaller area may be more beneficial when considering a pest. Like Hannah said, larger areas could also make it harder to capture the species. So, really size does matter when talking about protected areas. I would have thought a larger area would have been better, but I suppose it does depend on the species.
ReplyDeletePost by: Anna Potorski
I think that ideally, the reserves would be larger, but since local fishermen depends on the area for resources as well, the current reserve sizes may just be due to a compromise between resources and conservation. That being said, I’m not sure if a larger protected site would be better for managing sea star populations either. It seems to me that more coral would mean more food for the sea star, and population size of the sea stars would just go up in relation to the reserve size/amount of coral available.
DeletePosted by Haley Huang