Risk it or play it safe?
There is a bias towards placing MPAs in areas that are least threatened
We found that conservation targets in our study area could not be met solely by avoiding high threat areas
A threat selection strategy should be part of the management toolbox
Cost-effectiveness in spatial conservation prioritization has biased some marine protected areas placement towards least threatened sites (see the box ‘what is lost when minimising cost?’). Sometimes, however, it can be beneficial to protect highly impacted sites to directly address threats, enhance recovery, or establish local stewardship towards management.
We tested how conservation priorities differ between two management strategies:
- Avoid protecting high threat areas, or
- Protect areas at risk.
In the Sulu-Sulawesi region in the heart of the Coral Triangle, we found that conservation targets cannot be met solely with win-win areas that are priority areas for both strategies. Selecting for high threat areas required less habitat area to be protected to achieve the same conservation target and resulted in a more equitable distribution of priority sites per country and sub-region.
This demonstrates the importance of deciding on conservation objectives up-front: do we apply a ‘fire-fighting’ strategy of protecting threatened habitats that are often already degraded to increase their recovery or persistence probabilities (eg, reefs near human settlements where fishing pressure is higher) or a ‘pre-emptive’ strategy of protecting currently less threatened habitats that may face increasing stresses in the future (eg, remote reefs far away from where fishers currently go)?
Contrary to the common practice of avoiding threats in spatial planning, our results suggest that a threat selection strategy should be part of the management toolbox, particularly in transboundary planning for regions with widespread impact of marine threats, where it may be important to achieve shared conservation targets equitably.
What is lost when minimising cost?
Spatial conservation prioritisation aims to maximise conservation returns at the least possible cost. Fishing pressure is often incorporated as a surrogate for opportunity cost and minimising such opportunity costs reduces the impacts of a marine reserve on resource users.
However, it also leads to the establishment of marine protected areas in remote areas or places that are unpromising for extractive activities (like fishing). As a result, the areas most exposed to threatening processes are often given the least protection.
Nine of the 10 largest marine protected areas in the world, which account for more than 53% of global marine protected areas area, are largely established in remote and uninhabited places, making almost no difference to ‘business-as-usual’ fishing activities. Spatial planning’s political pragmatism in minimising costs to users thus risks shifting the primary objective away from biodiversity conservation.
Boon PY & M Beger (2016). The effect of contrasting threat mitigation objectives on spatial conservation priorities. Marine Policy 68: 23-29. http://dx.doi.org/10.1016/j.marpol.2016.02.010