A new scientific study on Marine Protected Areas in the Mediterranean has been published in Plos One.
In the article "Large-Scale Assessment of Mediterranean Marine Protected Areas Effects on Fish Assemblages" the researchers found that the level of protection greatly affected the fish communities. No-take MPAs showed the greatest recovery of fish communities, with recovery in intermediate-protection MPAs closer to that of unprotected areas. Furthermore, the numbers and total mass of apex predators, carnivores and detritivores were greater in no-take MPAs, compared with the other areas.
The estimated total weight of the fish per square metre of seabed and the numbers of different species were also significantly greater in the no-take MPAs compared with the other areas. In no-take zones, the average weight was approximately 84 g/m2 , compared with around 30 g/m2 in areas with intermediate protection and 10 g/m2 in non-enforced MPAs and unprotected areas.
Importantly, highly protected MPAs contained much greater densities of commercially valuable fish.The results showed that the numbers of invasive species or southern Mediterranean fish that thrive in warmer waters were similar in both MPAs and unprotected areas. Although this means that it is likely that MPAs do not protect against these threats, it also shows that the extra biodiversity found in MPAs was not driven by invasive or warm-water fish.
These results reinforce other studies of single MPAs, which have shown that highly protected areas offer the best chance for fish stocks and entire ecosystems to recover in the Mediterranean Sea.