Tuesday, October 2, 2018

CONSERVATION: The truth about Marine Protected Areas

MPA NewsUnique study of partially protected MPAs offers new insights on when they protect biodiversity and when they do not


Most of the world’s MPAs are partially protected: they restrict some extractive activities but allow others. For planners and decision-makers – especially in regions where extractive resource use is high – partially protected MPAs can be easier to designate than no-take areas. The partial protection indicates to resource users that socioeconomic and conservation objectives have been balanced.
How even that balance is, though, can depend on how partial the protection is. For example, an MPA that bans nearly all extraction might be expected to be better at conservation than one that allows nearly all extractive activities. But beyond such a broad generalization, how can we identify which forms of partial protection are in fact most effective in protecting biodiversity? And are weakly protective areas useful for conservation at all?
A new, unique study provides insights on these questions. As nations designate more MPAs, spurred by the approaching 2020 deadline for United Nations global marine protection targets, the study could prove valuable.
Highly regulated MPAs are effective; weakly regulated MPAs are not effective

Earlier studies of the effectiveness of partially protected areas (e.g., in 2013 and 2014) provided some insights but were limited. To classify levels of partial protection, these studies relied on relatively simple systems that were susceptible to inaccuracy. The 2014 study, for example, used the IUCN protected area management categories, which have been applied in different ways by different governments.
The new study, led by Mirta Zupan of MARE Marine and Environmental Sciences Centre in Portugal, applies a relatively novel classification system that was first described in 2016. The system categorizes MPAs – as well as each zone within them – according to allowed commercial and recreational uses. The more uses there are, the greater the cumulative impact, and that impact is reflected in an MPA’s overall score. The resulting classifications range from “fully protected” to “unprotected”, with various protection level categories in between. (MPA News reported on this system two years ago.)
The research team applied the classification system to 49 MPAs worldwide. These sites had already been studied for the effectiveness of their biodiversity conservation – namely, whether abundance and biomass of targeted fish species were higher in the MPAs than at control sites. Then the researchers compared how their conservation effectiveness correlated with three different levels of partial protection – “highly regulated”, “moderately regulated”, and “weakly regulated”. Highly regulated areas were defined as allowing five or fewer types of low-impact fishing gear (e.g., lines, octopus trap); moderately regulated areas allowed up to 10 low- to medium-impact fishing gear types (e.g., gillnets); and weakly regulated areas permitted higher-impact gear types, like beach seines or bottom trawling. (Although this study focused on fishing activity, the classification system does take non-fishing activities into consideration as well, like petroleum extraction or aquaculture.)
The findings were:
  • Highly regulated MPAs are effective for biodiversity protection;
  • Weakly regulated MPAs are never effective for biodiversity protection; and
  • Moderately regulated MPAs can be effective when adjacent to a fully protected area.


More at ... Unique study of partially protected MPAs offers new insights on when they protect biodiversity and when they do not | MPA News