Identifying and accounting for the wide-ranging ecological impacts associated with resource development is essential for mitigating ecosystem degradation and conserving biodiversity, ecological processes, and ecosystem services. Yet many ecological impacts are notoriously difficult to identify and measure, let alone mitigate. Such impacts tend to ‘slip under the radar’ of conventional impact assessments.
Ecological impacts overlooked in impact assessments include multiple small impacts that are significant in sum (cumulative impacts); impacts outside of the development footprint or the area assessed (offsite impacts); impacts not detectable with the methods or spatiotemporal scales used (cryptic impacts); impacts facilitated, but not directly caused, by the development (secondary impacts). Lastly, multiple impacts can have synergistic effects or one impact might facilitate another (e.g., logging can faciliate human-ignited forest fires in the Brazilian Amazon).
Linear infrastructure is a particularly pervasive form of development with many associated impacts that are commonly overlooked in impact assessments. Explosive expansion of linear infrastructure such as roads, tracks, railways, pipelines and exploration gridlines is a major factor driving habitat loss and fragmentation (i.e., cumulative impacts). Linear infrastructure is also associated with dust, noise, and light pollution, and changes to microclimates, water flows and predator activity (i.e., offsite impacts); barrier effects and internal fragmentation, and pathways for disease and pest species invasions (i.e., cryptic impacts); and logging, fauna mortality and overhunting (i.e., secondary impacts). What’s more, the size and extent of linear infrastructure networks are often not well known, poorly mapped and inadequately managed.
Potential solutions to address the sum total ecological impacts of development include strategic assessments and planning (e.g., no-development zones), improving professional practice (e.g., cumulative assessments, addressing historical impacts) and environmental insurance schemes.