Marine reserves are one of the most effective management tools for protecting ocean biodiversity. They provide a connected network that can support both conservation goals and sustainable fisheries management goals. However, many marine reserves in existence today were designed without accounting for climate change, and it’s unclear whether the current spatial arrangement of marine reserve networks will be still be effective in the future.
A recent study looks at the value of redesigning marine reserves to account for climate change with seven managed species found in a cluster of marine reserves in the nearshore waters of California. Using models and data from the Southern California phase of the Marine Life Protection Act (MLPA) process, the study looked at future larval dispersal under climate change and how connectivity might be affected by marine reserve spatial design. The main question was: how well will current marine reserves work under future conditions?
The good news is that, although there is a difference between marine reserves designed for today’s climate conditions compared to those designed for future climates, there is relatively little improvement in redesigned networks over the initial design. Re-optimizing marine reserves in response to climate change would require substantial alteration, and there is little indication this alteration would have significantly large impacts. Further supporting the effectiveness of existing reserve networks is the outcome that strategically designed reserves far outperform reserve networks that are randomly designed.
It is important to note that for all seven species studies, results show that climate change will almost certainly alter patterns of larval dispersal, and these changes will be highly variable and species specific.
The key take-away is that marine reserve networks work, even when not designed explicitly for climate change. New marine reserves in the future might be more effective if they incorporate projected climate conditions, and novel design ideas such as mobile borders might help support connectivity across these networks even further. However, as studies like this show, managing for climate change doesn’t always require huge changes in existing systems.
Rassweiler, A., Ojea, E. and Costello, C. 2020. Strategically designed marine reserve networks are robust to climate change driven shifts in population connectivity. Environmental Research Letters.