Mapping status and conservation of global at‐risk marine biodiversity

Casey C O'Hara,Juan Carlos Villaseñor‐Derbez,Benjamin S Halpern,Gina M Ralph

doi:10.1111/conl.12651

Abstract

AbstractTo conserve marine biodiversity, we must first understand the spatial distribution and status of at‐risk biodiversity. We combined range maps and conservation status for 5,291 marine species to map the global distribution of extinction risk of marine biodiversity. We find that for 83% of the ocean, >25% of assessed species are considered threatened, and 15% of the ocean shows >50% of assessed species threatened when weighting for range‐limited species. By comparing mean extinction risk of marine biodiversity to no‐take marine reserve placement, we identify regions where reserves preferentially afford proactive protection (i.e., preserving low‐risk areas) or reactive protection (i.e., mitigating high‐risk areas), indicating opportunities and needs for effective future protection at national and regional scales. In addition, elevated risk to high seas biodiversity highlights the need for credible protection and minimization of threatening activities in international waters.

Highlights

Global oceans face increasing pressures from the direct and indirect consequences of human activities, including climate change (Poloczanska et al, 2016), fishing, pollution, and habitat destruction (Halpern et al, 2008, 2015). These stressors threaten the sustainability and existence of marine biodiversity (Dulvy, Sadovy, & Reynolds, 2003; Sala & Knowlton, 2006) and the suite of benefits these ecosystems provide (McCauley et al, 2015; Worm et al, 2006). Recognizing these threats, the Aichi Biodiversity Targets adopted by the United Nations Convention on Biodiversity (CBD) in 2010 incorporate strategic goals to counteract the decline in global biodiversity
We find that the global mean of biodiversity risk significantly centers just below Near Threatened (0.184 ± 0.043; mean ± SD; Figure 1a)
Coastal and continental shelf regions generally display lower risk than open ocean basins, despite expectations of higher cumulative human impact (Halpern et al, 2008), notably in the South China Sea and the Coral Triangle; the presence of species at high threat levels is masked by a greater presence of coastal species assessed as Least Concern

Summary

Introduction

Global oceans face increasing pressures from the direct and indirect consequences of human activities, including climate change (Poloczanska et al, 2016), fishing, pollution, and habitat destruction (Halpern et al, 2008, 2015). These stressors threaten the sustainability and existence of marine biodiversity (Dulvy, Sadovy, & Reynolds, 2003; Sala & Knowlton, 2006) and the suite of benefits these ecosystems provide (McCauley et al, 2015; Worm et al, 2006). A baseline assessment of global marine biodiversity conservation status relative to existing marine protection will be critical to inform renegotiations of protection targets toward a post-2020 biodiversity framework

Methods

Results

Conclusion