Setting Priorities to Conserve Marine Biodiversity

Elizabeth Selig is Director of Marine Science at Conservation International.

Understanding broad-scale patterns of biodiversity and human impacts is essential to developing effective conservation strategies and prioritizing investment. Previously, these types of prioritization efforts have focused on terrestrial regions. So how do we set priorities in a vast ecosystem like the ocean? Working with scientists from the University of California – Santa Barbara, Albert –Ludwigs University of Freiburg , the International Union for the Conservation of Nature and Birdlife International, we recently published a paper in the journal PLOS ONE that describes how to prioritize places for biodiversity conservation in the oceans.
 
 
We began by compiling the most extensive database of species range maps for more than 12,500 species including corals, fish, invertebrates, sharks, rays, mammals, and seabirds. With these data, we were able to identify globally which places in the oceans have the highest numbers of species, the highest numbers of relatively rare species, or the highest percentage of rare species. We then coupled these biodiversity maps with a map of cumulative human impacts from fishing, ocean-based pollution, land-based pollution, and climate change. By combining these data, we were able to identify priorities as places with high biodiversity and either high or low levels of impact from a range of human activities.
 

Global Conservation Priorities- Orange denotes places that are highly impacted by human activities and blue denotes places with low levels of human impacts

High diversity – high impact places are priorities for conservation because they are most in jeopardy of being lost.  High diversity – low impact places represent opportunities for conservation before they are degraded.
 
Our analyses highlighted places that are well-known centers of biodiversity like those in the Coral Triangle, which stretches across the waters of Indonesia, the Philippines, Malaysia, Papua New Guinea, the Solomon Islands, and Timor-Leste.  However, we also identified conservation priorities in less well-known locations in the southwest Indian Ocean, western Pacific Ocean, Arctic and Antarctic Oceans, and within semi-enclosed seas like the Mediterranean and Baltic Seas.  In priority areas, the biggest impacts were from climate change and fishing, which suggests that we need to prioritize improved fisheries governance as well as work to implement policies aimed at mitigating climate change. 
 
We believe that this approach can be useful to the Global Partnership for Oceans in determining priorities for investment at the global or regional level. Our approach is designed to be a flexible, first step towards designing conservation portfolios by highlighting areas based on general principles.  For example, our analysis specifically focused on severely impacted or relatively unimpacted places, but thresholds could be shifted to facilitate a broader identification of priority areas.  Depending on goals, conservation investments may want to protect high or low human impact areas or they may be more interested in places with more moderate levels of impact.  
 
Although our original analysis focused only on biodiversity and human impact, other kinds of information could be incorporated as well.  Future analyses will focus on incorporating data on ecosystem services and human well-being to identify where human populations are most vulnerable to changes in marine ecosystem health.  Our approach could also be tailored to use regional thresholds for biodiversity or impact.  For example, the Caribbean is a naturally less species rich region so not many places are identified at a global scale.  Using regional thresholds would allow identification of high diversity areas specific to that region.   Although new priorities may be identified when new species data become available, these results can provide a critical first step towards identifying places for biodiversity conservation in our oceans.