Marine Protected Areas: are they the hoped for success?

Marine Protected Areas (MPAs) and No Take Reserves (NTRs) have been instituted worldwide, from the South China Sea to the North Atlantic to the Mediterranean, as a method to not only preserve marine environments but also provide a means to ensure a reasonable population outside of the zone for commercial fishing. While common sense might dictate that these zones would logically improve the health of a marine environment, there are many challenges in empirically proving it.

While an MPA or an NTR may have a defined boundary, those limits have not been, shall we say, "communicated" to the marine life below the surface and so spatial density, or spillover as it is sometimes called, becomes a critical component. A healthy zone that generates populations of species that extend beyond its borders and provides a reasonable commercial yield, does not do so in a vacuum. There must be a proper flow of incoming influences including plankton, coral, and fish larval stages and other biosystem factors - all of which pay no attention to a zone's arbitrary boundaries.

While preliminary results appear positive, there is a considerable amount of challenging research taking place:

• Studying the impact of political/public use influences on the size (reduction) of a zone versus initial environmental recommendations (preliminary research indicates the negative effect is disproportionately larger than the amount of size reduction).
• Researchers are often challenged by a lack of extensive baseline studies of ecosystems prior to the zone for use in evaluating against post-zone studies.
• Much research needs to be done to document the relationship/effect of multiple MPAs or NTRs and how they interact with each other.

To date there have not been any major negative ecological effects attributed to MPAs and NTRs, but let's hope with more research over time, we will have the body of data to undeniably prove their effectiveness and how we can maximize or improve on that success for both environmental and commercial interests.