# Environmental Factors Influencing the Establishment of the Invasive Australian Redclaw Crayfish (Cherax quadricarinatus) in a Biosphere Reserve on the Central Mexican Plateau

## TL;DR

This study examines how environmental degradation helps invasive redclaw crayfish establish in a Mexican biosphere reserve.

## Contribution

The study identifies specific environmental factors linked to the spread of invasive crayfish in a Central Mexican Plateau reserve.

## Key findings

- Crayfish abundance correlates with degraded water quality and habitat conditions.
- Higher total dissolved solids and substrate embedment support crayfish establishment.
- Native macroinvertebrate diversity inversely relates to crayfish abundance.

## Abstract

Crustaceans are among the most successful taxonomic groups in invasions worldwide. Humans can facilitate these invasions through introductions and disturbances in habitats. The Australian redclaw crayfish (Cherax quadricarinatus) is an invasive species with significant global ecosystem impacts. This species inhabits the Sierra Gorda Biosphere Reserve, in the Central Mexican Plateau. We hypothesize that environmental degradation facilitates the establishment and expansion of invasive crayfish. Seven sites along the Santa María River, within the reserve buffer zone, were assessed for seven months in 2023. We analyzed the abundance and density of the Australian redclaw crayfish in correlation with the environmental quality of the habitat. The results confirm that the establishment and spread of crayfish populations are related to water quality degradation and habitat alteration. The associated variables include increased total dissolved solids, greater substrate embedment, and degraded conditions on stream banks. Furthermore, the inverse relationship between the abundance of Australian redclaw crayfish and macroinvertebrate richness reinforces the hypothesis that more diverse native communities reduce the success of invaders. This study highlights the urgent need to implement management strategies focused on habitat restoration and the control of reproductive populations through the extirpation of mature individuals as critical measures for controlling the establishment and expansion of the invasive Australian redclaw crayfish.