Integrating climate, water chemistry and propagule pressure indicators into aquatic species distribution models

• Published in: Ecological indicators 2020-05, Vol.112, p.106060, Article 106060
• Main Authors: Gallardo, Belinda, Castro-Díez, Pilar, Saldaña-López, Asunción, Alonso, Álvaro
• Format: Article
• Language: English
• Subjects: Accessibility; Maxent; New Zealand mud snail; Potamopyrgus antipodarum; Propagule pressure; Samples With Data
• ISSN: 1470-160X; 1872-7034
• DOI: 10.1016/j.ecolind.2019.106060

•We explored the potential distribution of the New Zealand Mud Snail (NZMS).•Propagule pressure expanded the area susceptible to invasion by 16–36%.•Accessibility is the single most important indicator of invasiveness.•Nitrate concentration explained 18% of the NZMS distribution at catchment scale.•Integrated models can support prioritization of monitoring and management resources. Species distribution models are frequently used to anticipate the expansion of invasive species under the assumption that climate affects habitat conditions. Here, we investigated the influence of two additional factors that determine the spread, establishment, and impact of aquatic organisms: propagule pressure and water chemistry. Our case study species is the New Zealand Mud Snail (Potamopyrgus antipodarum, Tateidae, Mollusca), one of the 100 worst invasive species in Europe. We calibrated species distribution models combining three types of indicators (climate, water chemistry, and propagule pressure), and two scales (Iberian Peninsula vs. Ebro River catchment) using the Maxent algorithm. Propagule pressure improved the accuracy of models and enlarged the area susceptible to invasion by 16% at the Iberian Peninsula scale, and by 36% at the catchment scale. Among propagule pressure indicators, accessibility was the single most important indicator of the species distribution (33–35% contribution), illustrating the role of human-mediated dispersal for aquatic invaders. The catchment model integrating climate, propagule pressure and water chemistry indicators was the best option to prioritize river segments most vulnerable to colonization, characterized by high temperature, human influence and water pollution (nitrate concentration). High risk areas according to our models include the Mediterranean and North Atlantic coasts, central Spain, and the lowlands of the Ebro River catchment. Based on this study, we recommend including indicators of propagule pressure such as accessibility to reflect the opportunity to invade, and using water chemistry to further prioritize the river stretches most suitable to invasion. We conclude that distribution models integrating indicators at multiple scales are feasible, consistent in their predictions across scales, and show great potential to optimize management resources towards the prevention and early eradication of aquatic invasive species.