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  • 07 Apr 2014

Noting a largely unmet need for integrated guidelines for practitioners who wish to design marine reserves that simultaneously address objectives on fisheries, biodiversity, and climate change, a paper published in a recent issue of the journal Coastal Management (external link) presents a set of ecological considerations and guidelines for multi-objective marine reserve network design.

“Previous studies provided advice regarding ecological guidelines for designing marine reserves to achieve one or two of these objectives. While there are many similarities in these guidelines, there are key differences that provide conflicting advice. Thus, there is a need to provide integrated guidelines for practitioners who wish to design marine reserves to achieve all three objectives simultaneously,” the authors note, highlighting new scientific findings on fish stocks, habitat connectivity, recovery rates, and vulnerability to climate-ocean change that allow for refinement of existing marine reserve design advice.

The paper offers guidelines to simultaneously achieve fisheries, biodiversity, and climate change objectives, based on six ecological considerations, summarized below:

  1. Habitat representation – To maximize benefits to fisheries management and biodiversity conservation under climate change, marine reserves should encompass 20–40% of each major habitat, depending on fishing pressure and the effectiveness of fisheries management outside reserves. If fishing pressure is high and protection is only provided by marine reserves, the proportion should be greater than 30%. If effective fisheries management is in place outside reserves or fishing pressure is low, 20% protection may suffice.
  2. Risk spreading – Protect at least three examples of each major habitat in marine reserves, spaced to reduce the chance that all examples will be impacted by the same disturbance.
  3. Protecting critical, special, and unique areas – Protect habitats that species use throughout their life cycles, especially during critical phases, and ensure reserves are spaced to allow movement among habitats. If these areas’ locations are known, they should be protected in permanent or seasonal reserves. If unknown, or if species move over large scales, protection should be achieved through a network of reserves combined with other management approaches.
  4. Allowing time for recovery – Short-term benefits (less than 5 years) are possible, particularly in low-fishing-pressure areas, but long-term protection (20–40 years, preferably permanent) allows species to mature, increase biomass, and produce robust eggs and larvae. Short-term or periodic reserves should complement, not replace, long-term reserves.
  5. Adapting to changes in climate and ocean chemistry – Protect potential climate change refugia—areas where species and habitats have historically withstood environmental extremes, where sea surface temperatures and ocean chemistry are variable, or where low-lying adjacent areas allow habitat expansion under sea-level rise—as these areas help sustain fisheries and biodiversity under climate change.
  6. Minimizing and avoiding local threats – Prioritize protection of areas likely to contribute to ecosystem health, fisheries productivity, and climate resilience. Manage threats originating inside reserves (e.g., overfishing, destructive activities) within reserves, and address external threats (e.g., sediment and nutrient runoff) through broader management frameworks.

The authors further recommend that when compromises are necessary, practitioners should prioritize applying ecological guidelines regarding habitat representation, replication of major habitats, and minimizing local threats, as this increases the likelihood of protecting species, habitats, processes of importance, and resilience to unpredictable disturbances.

The publisher is offering free access to the full report until April 30, 2014. To access it, click here (external link).