EPPO Global Database

EPPO Reporting Service no. 06 - 2024 Num. article: 2024/143

The economic costs of aquatic and semi-aquatic invasive plants


Aquatic invasive alien plants can incur an array of negative impacts on the habitats they invade ranging from negative impacts on biodiversity, ecosystem services – including cultural impacts by degrading waterbodies aesthetic value or restricting recreational activities; to blocking sunlight which can affect nutrient cycling; to blocking irrigation systems and drainage ditches. Control measures can be both laborious and costly. Data on economic impacts of invasive aquatic and semi-aquatic plants, was obtained from the on-line open access database InvaCost to assess the global economic impact. Over 1670 records were used in the study. Statistical models were used to examine the recorded costs over time. Between 1975 and 2020, the total cost of aquatic and semi-aquatic invasive plants to the global economy exceeded 32 billion USD, of which the majority of recorded costs (57 %) was attributable to multiple or unspecified taxa. Submerged plants had costs of 8.4 billion USD (25.5 %) followed by floating plants 4.7 billion USD (14.5 %), emergent 684 million USD (2.1 %) and semi-aquatic 306 million USD (0.9 %). In terms of impacted sectors, costs from published material included: government expenditure  (8.9 billion USD), fishery (7.6 billion USD), authorities-stakeholders (2.0 billion USD), environment (977 million USD), agriculture (24 million USD), and the health sector (25.5 USD) had the lowest monetary impacts. Reported costs constituted economic damage, management and a mixture of costs or unspecified. Most of the costs were attributed to species level taxa, e.g. Elodea spp., or Ludwigia spp. However, where data was available for single species, ten species had significant economic impacts (Table 1).


Table 1. The ten costliest species from the study.

Species

Family

Plant type

EPPO Status

Alternanthera philoxeroides 

Amaranthaceae

Emergent - Freshwater

A2

Azolla filiculoides

Salviniaceae

Floating - Freshwater

Obs. List

Caulerpa taxifolia 

Caulerpaceae

Submerged - Marine


Elodea canadensis 

Hydrocharitaceae

Submerged - Freshwater


Hydrilla verticillata 

Hydrocharitaceae

Submerged - Freshwater

List IAP

Hydrocotyle ranunculoides 

Araliaceae

Floating - Freshwater

A2

Lythrum salicaria 

Lythraceae

Semi-aquatic - Freshwater


Pontederia crassipes 

Pontederiaceae

Floating - Freshwater

A2

Spartina alterniflora

Poaceae

Emergent - Brackish


Spartina cynosuroides 

Poaceae

Emergent - Brackish


 For EPPO Status List IAP = EPPO List of Invasive Alien Plants; Obs. List = EPPO Observation List.


Sources

Macĕdo RL, Haubrock PJ, Klippe G, Fernandez RD, Leroy B, Angulo E, Carneiro L, Musseau CL, Rocha O, Cuthbert RN (2024) The economic cost of invasive cost of invasive aquatic plants: A global perspective on ecology and management gaps. Science of the Total Environment, https://doi.org/10.1016/j.scitotenv.2023.168217

Diagne C, Leroy B, Gozlan R, Vaissière AC, Assailly C, Nuninger L (2020) InvaCost: Economic cost estimates associated with biological invasions worldwide. Figshare. Dataset. https://doi.org/10.6084/m9.figshare.12668570.v5