Fragmented yet high economic costs of biological invasions in India

Abstract Biological invasions are one of the top drivers of the ongoing biodiversity crisis. An underestimated consequence of invasions is the enormity of their economic impacts. Knowledge gaps regarding economic costs produced by invasive alien species (IAS) are pervasive, particularly for emerging economies such as India — the fastest growing economy worldwide. To bridge this gap, we synthesised data on economic costs of IAS in India. Specifically, we examine how IAS costs are distributed spatially, environmentally, sectorally, taxonomically, temporally and across introduction pathways; and discuss globally how IAS costs vary with socioeconomic indicators. We found that IAS have cost the Indian economy between at least US$ 127.3 billion to 182.6 billion (Indian Rupees ₹ 8.3 trillion to 11.9 trillion) over 1960–2020, and these costs have increased with time. Most recorded costs were not assigned to specific regions, environments, sectors, cost types and causal IAS. When costs were specifically assigned, maximum costs were incurred in west, south and north India, by invasive alien insects in semi-aquatic ecosystems, incurred mainly by the public and social welfare sector, and were associated with damages and losses rather than management expenses. Our findings indicate that the reported economic costs grossly underestimate the actual costs, especially when considering the expected costs given India's population size and gross domestic product (GDP). This cost analysis improves our knowledge of the negative economic impacts associated with biological invasions in India and the burden they can represent for its development. We hope that this study motivates policymakers to address socio-ecological issues, especially since economic growth will be accompanied by greater impacts of global change.