Will current marine reserve networks still be effective under climate change?

fish school

Marine reserve networks help populations stay connected across large seascapes, but that connectivity is likely to be altered under future climate change.

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?

Red sea urchin

Species in the study included Red Sea Urchin (pictured), Kelp Rockfish, Opaleye, California Halibut, , Kelp Bass, Ocean Whitefish, and Sheephead. Credit: Christian Ferrer.

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.

Resources

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.

Creating marine protected areas with mobile boundaries (January 2020)

2020-03-06T10:57:10-05:00 March 30th, 2020|

About the Author:

Heather Cayton
Heather Cayton is the Managing Director of ConservationCorridor.org and a Research Assistant at Michigan State University. She received her B.S. from the University of Virginia and her M.S. from Virginia Tech, and has spent over 10 years studying corridors and rare butterflies in North Carolina.