Alternative Routes for a Proposed Nigerian Superhighway to Limit Damage to Rare Ecosystems and Wildlife

Abstract

The Cross River State Government in Nigeria is proposing to construct a ''Cross River Superhighway'' that would bisect critical remaining areas of tropical rainforest in south eastern Nigeria. We offer and evaluate two alternative routes to the superhighway that would be less damaging to forests, protected areas, and biological diversity. The first alternative we identified avoids intact forests entirely while seeking to benefit agriculture and existing settlements. The second alternative also avoids intact forests while incorporating existing paved and unpaved roads to limit construction costs. As currently proposed, the superhighway would be 260 km long, would intersect 115 km of intact forests or protected areas, and would cost an estimated US$2.5 billion to construct. Alternative Routes 1 and 2 are only slightly longer (290 and 353 km, respectively) and have markedly lower estimated construction costs (US$0.92 billion). Furthermore, the alternative routes would have negligible impacts on forests and protected areas and would be better aligned to benefit local communities and agriculture. We argue that alternative routings such as those we examined here could markedly reduce the economic and environmental costs, and potentially increase the socioeconomic benefits, for the proposed Cross River Superhighway.

Status of Road Ecology Research in Africa: Do We Understand the Impacts of Roads, and How to Successfully Mitigate Them?

“…There are over 30 development corridors planned across Africa, spanning over 53,000 km in length, and potentially affecting protected areas with high conservation value (Laurance et al, 2015b;Sloan et al, 2017). For instance, the proposed Cross River Calabar-Ikom-Kastina Ala Superhighway in Nigeria will effectively bisect some of Nigeria's last remaining intact forests (Mahmoud et al, 2017), and a proposed road to the gold fields near Lake Victoria in Tanzania could bisect the Serengeti National Park and disrupt one of the world's greatest remaining migrations of terrestrial wildlife (Haas, 2011). That these developments are being considered within areas of such high conservation and cultural value reflects a broader, concerning trend across Africa as a whole, whereby natural-resource extraction and related transportationinfrastructure development are often seen as the priority land-use, regardless of other factors (Mahmoud et al, 2017).…”

“…For instance, the proposed Cross River Calabar-Ikom-Kastina Ala Superhighway in Nigeria will effectively bisect some of Nigeria's last remaining intact forests (Mahmoud et al, 2017), and a proposed road to the gold fields near Lake Victoria in Tanzania could bisect the Serengeti National Park and disrupt one of the world's greatest remaining migrations of terrestrial wildlife (Haas, 2011). That these developments are being considered within areas of such high conservation and cultural value reflects a broader, concerning trend across Africa as a whole, whereby natural-resource extraction and related transportationinfrastructure development are often seen as the priority land-use, regardless of other factors (Mahmoud et al, 2017). Successful movement of individual organisms is critical to a species' survival and facilitating these movements by promoting ecological connectivity has become a central theme in ecology and conservation (LaPoint et al, 2015).…”

Roads & SDGs, tradeoffs and synergies: learning from Brazil’s Amazon in distinguishing frontiers

“…If roads have more impact on economic growth when prior development is significant, such as near cities (Anderson et al 2002 find this for the Brazilian Amazon), then perhaps both urban economic growth and standing forests could benefit from patterns of investment in transport that are oriented around big cities. If roads cause greater damage to ecosystems on isolated, currently intact frontiers, that too could guide road siting away from rural spaces (see, e.g., Mahmoud et al 2017 about a proposed highway in Nigeria).…”

What future for primates? Conservation struggles in the forests of Cross River State, Nigeria

“…The ongoing expansion of urban areas and agricultural land, together with new infrastructure and road building projects further reduces the area and quality of forest habitats (Mahmoud et al 2017). Albeit road construction may facilitate access to markets to purchase animal protein, easier access into remote areas puts additional pressures on forests facilitating timber extraction and hunting (Laurance et al 2017).…”