Economic costs of invasive bivalves in freshwater ecosystems

Aim To assess spatio-temporal and taxonomic patterns of available information on the costs of invasive freshwater bivalves, as well as to identify knowledge gaps. Location Global. Time period 1980-2020. Taxon studied Bivalvia. Methods We synthesize published global economic costs of impacts from freshwater bivalves using the InvaCost database and associated R package, explicitly considering the reliability of estimation methodologies, cost types, economic sectors and impacted regions. Results Cumulative total global costs of invasive macrofouling bivalves were $ 63.7 billion (2017 US$) across all regions and socio-economic sectors between 1980 and 2020. Costs were heavily biased taxonomically and spatially, dominated by two families, Dreissenidae and Cyrenidae (Corbiculidae), and largely reported in North America. The greatest share of reported costs ($ 31.5 billion) did not make the distinction between damage and management. However, of those that did, damages and resource losses were one order of magnitude higher ($ 30.5 billion) than control or preventative measures ($ 1.7 billion). Moreover, although many impacted socio-economic sectors lacked specification, the largest shares of costs were incurred by authorities and stakeholders ($ 27.7 billion, e.g., public and private sector interventions) and through impacts on public and social welfare ($ 10.1 billion, e.g., via power/drinking water plant and irrigation system damage) in North America. Average cost estimates over the entire period amounted to approximately $ 1.6 billion per year, most of which was incurred in North America. Main conclusions Our results highlight the burgeoning economic threat caused by invasive freshwater bivalves, offering a strong economic incentive to invest in preventative management such as biosecurity and rapid response eradications. Even if the damages and resource losses are severely understated because economic impacts are lacking for most invaded countries and invasive bivalve species, these impacts are substantial and likely growing.

Automated summary

This study assesses the spatio-temporal and taxonomic patterns of costs associated with invasive freshwater bivalves and identifies knowledge gaps. The results reveal that the cumulative global costs of invasive macrofouling bivalves amounted to $63.7 billion between 1980 and 2020, with significant taxonomic and spatial biases, primarily concentrated in North America.