- Marine Protected Areas (MPAs): “include biosphere reserves and national parks (IUCN categories Ia, Ib, and II) and targets strict protection.” (128)
- Species Management Protected Areas (SPAs): “managed for specific species and habitats (IUCN category IV), and allow some types of resource extraction.” (128)
- Differences of protected areas (PAs) versus control villages
- “compared to control villages, PA villages are poorer, less suitable for agriculture, on steeper slopes, with fewer navigable rivers, have higher population density, and have more mangroves in 2000.” (132)
- “PAs have a moderately statistically significant effect on reducing mangrove loss rates — on average, 10% reduction in mangrove loss from 2000 to 2006.” (132)
- MPAs are effective at preventing losses of mangroves, reducing mangrove loss by approximately 14,000 hectares. SPAs, on the other hand, are not effective. It is likely that this difference is due to the strict requirements of MPAs and the fact that SPAs only apply to specific species. SPAs also cannot generate revenue through tourism to the same extent that MPAs can.
- “[marine PAs] reduced mangrove loss by 13% from 2000 to 2006. In contrast, [species management PAs] did not have a statistically significant effect on mangrove outcomes.” (132)
- There is no evidence that marine protected areas lead to increased extraction at other unprotected areas. Furthermore, marine protected areas for mangroves in Indonesia helped to avoid emissions of approximately 13 million metric tons of carbon.
- “Monetizing [13 million metric tons of blue carbon] via the social cost of carbon (roughly $41/ton of CO2e base on Pendleton et al, 2012) would yield social welfare benefits of $540 million.” (134)
- Other impacts of PAs
- “PA establishment may displace extraction to nearby unprotected areas or to the buffer zones, a phenomenon sometimes known as spillovers, slippage or leakage (Murray, 2009). However, we did not find evidence that PAs resulted in spillovers.” (134)
- “Vincent (2015) has posited that PA managers could be protecting key species and habitats (e.g., old growth mangroves), even though the average impacts seem small.” (134)