Using Cumulative Impact Mapping to Prioritize Marine Conservation Efforts in Equatorial Guinea

Brittany T Trew,Tim Collins,Kristian Metcalfe,Angela Formia,Christian Barrientos,Richard J Parnell,Brendan J Godley,Philip D Doherty,Sara M Maxwell,Hedley S Grantham,Matthew J Witt,Dominic Tilley,Stephen K Pikesley

doi:10.3389/fmars.2019.00717

Abstract

Marine biodiversity is under extreme pressure from anthropogenic activity globally, leading to calls to protect at least 10% of the world’s oceans within marine protected areas (MPAs) and other effective area-based conservation measures by 2020. Fulfilling such commitments, however, requires a detailed understanding of the distribution of potentially detrimental human activities, and their predicted impacts. One such approach that is being increasingly used to strengthen our understanding of human impacts is cumulative impact mapping; as it can help identify economic sectors with the greatest potential impact on species and ecosystems in order to prioritise conservation management strategies, providing clear direction for intervention. In this paper, we present the first local cumulative utilisation impact mapping exercise for the Bioko-Corisco-Continental area of Equatorial Guinea’s Exclusive Economic Zone – situated in the Gulf of Guinea one of the most important and least studied marine regions in the Eastern Central Atlantic. This study examines the potential impact of ten direct anthropogenic activities on a suite of key marine megafauna species and reveals that the most suitable habitats for these species, located on the continental shelf, are subject to the highest threat scores. However, in some coastal areas, the persistence of highly suitable habitat subject to lower threat scores suggests that there are still several strategic areas that are less impacted by human activity that may be suitable sites for protected area expansion. Highlighting both the areas with potentially the highest impact, and those with lower impact levels, as well as particularly damaging activities can inform the direction of future conservation initiatives in the region.

Highlights

Marine ecosystems play a critical role in supporting human well-being, providing numerous services such as food, livelihood and recreational opportunities (Halpern et al, 2012; Spalding et al, 2014; Barbier, 2017)
The Ensemble Ecological Niche Modeling (EENM) revealed that suitable habitat for all species (Atlantic humpback dolphin, bottlenose dolphin, humpback whale, leatherback and olive ridley sea turtle) were concentrated in the waters surrounding the Rio Muni mainland, Corisco Bay, and Bioko Island (Figure 2)
Despite the Gulf of Guinea being identified as a marine biodiversity hotspot, many countries in the region are failing to adequately protect and manage marine biodiversity from anthropogenic threats such as overfishing, and coastal and offshore developments (Aryeetey, 2002; Marinesque et al, 2012; Watson et al, 2014; Pérez-Jorge et al, 2015)

Summary

Introduction

Marine ecosystems play a critical role in supporting human well-being, providing numerous services such as food, livelihood and recreational opportunities (Halpern et al, 2012; Spalding et al, 2014; Barbier, 2017). These ecosystems face a multitude of pressures from human activities (Halpern et al, 2008), which have altered marine communities, impacted ecosystem health and eroded their capacity to provide benefits for local communities (Halpern et al, 2012). These maps are regularly used as part of decisionmaking processes, as well as to inform decisions regarding where to prioritize and target conservation efforts and funding (Myers et al, 2000; Salafsky and Margoluis, 2003)

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Conclusion