The topic of MPAs (marine protected areas) came up during lecture today, which got me wondering just how effective these protected areas are. Although there are varying degrees of protection of both marine and surface regions, for example, limits on fishing/hunting season and catch, as opposed to a flat out ban on fishing/hunting, it seems as though a protection of just one area wouldn’t be very effective for marine conservation on the whole.
That sounded really unclear, didn’t it?
Alright. On one hand, it is definitely beneficial for the region’s repopulation of fish and for coral growth. Fish larvae for example, can flow with the current to another area (maybe one that isn’t protected), and increase the fish stocks there. So this would work like a spillover effect of sorts. And so on the whole, the entire ocean benefits.
But if we take in account how one of the most pressing problems that the oceans face today is rising temperatures, then it wouldn’t matter which areas are protected or not. Take the example of the Nomura’s jellyfish. The jellyfish thrives in warm waters, and originates from the Yangtze River in China. However, every year, it makes its way to Japan to breed, devastating the fishstocks there. If we were to make the Nomura’s jellyfish representative of increasing sea temperature, then even if we were to designate certain regions as MPAs, it would be near impossible to fully protect these areas from heating up. (Article: Rising Ocean Temperatures Harm Protected Coral Reefs) I guess what I’m trying to say is that the ocean does not exist in parts, it exists as a whole.
This paper by Selig and Bruno (2010) showed that over a span of 38 years, although there was no depletion of corals in MPAs, there was also no significant increase in coral cover. One reason for such a finding could be that corals take thousands of years to form, which means that the protection of these MPAs have to be consistently rigorous and extremely enduring. This report from WWF (2005) points out that MPAs are not beneficial for some species such as the Bottlenose Dolphin and Sunset Star Coral. Although it is suggested that the dolphins may have merely expanded their range, such issues should definitely be considered if we were to set up/assess the effectiveness of MPAs.
It would be naive to think that MPAs are the sole solution to save the oceans. Though most MPAs have shown to be beneficial and effective, rising sea temperatures seem to be one of the factors undermining the success of protection zones. Therefore, humans would have to combat the one thing that MPAs can’t protect the oceans from – global warming, and that’s by reducing our impact on the planet.