Development of a Trait-Based Risk Assessment to Minimise the Impacts of Trout on New Zealand Native Fishes

Coughlan, Ami, Canning, Adam D., and Death, Russell G. (2025) Development of a Trait-Based Risk Assessment to Minimise the Impacts of Trout on New Zealand Native Fishes. Ecology and Evolution, 15. e72480.

[img]
Preview
PDF
Download (997kB) | Preview
DOI: 10.1002.ec3.72480
View at Publisher Website: https://doi.org/10.1002/ece3.72480
 
1


Abstract

The management of introduced species to protect native fauna in the face of their rapid decline often presents a costly, technically complex, and sometimes socially controversial challenge. Prioritising when and where conservation efforts are best applied for the greatest efficacy is difficult. Using a systematic risk assessment framework effectively prioritises options among the range of management alternatives. Tensions exist between managing trout in New Zealand as a highly valued sport fishery and conserving native freshwater fish populations. We developed a trait-based risk assessment matrix to identify the native fish most vulnerable to trout pressures and prioritise river reaches where those species are abundant for conservation focus. The trait-based assessment indicated that all species identified as highly vulnerable to trout pressures were either non-migratory galaxiids or mudfish. Trout overlapped in occurrence with approximately 10% of the entire extent of species deemed high risk to trout pressures, equating to 1626 km of river length, largely in central Otago and Hawkes Bay. While 1626 km of river is small compared to the entire riverine network (0.4%), it is still a substantial area for resource conservation interventions. Improving habitat quality to bolster native fish resilience to trout pressures, removing or reducing trout abundance are, however, potentially effective options. The approach adopted here will allow conservation managers to direct these actions to areas where they result in the greatest likelihood of positive outcomes.

Item ID: 91094
Item Type: Article (Research - C1)
ISSN: 2045-7758
Keywords: fish conservation, introduced species management, New Zealand, Oncorhynchus mykiss, risk assessment, Salmo tru
Copyright Information: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2025 The Author(s). Ecology and Evolution published by British Ecological Society and John Wiley & Sons Ltd.
Date Deposited: 02 Apr 2026 01:52
FoR Codes: 31 BIOLOGICAL SCIENCES > 3103 Ecology > 310304 Freshwater ecology @ 30%
41 ENVIRONMENTAL SCIENCES > 4101 Climate change impacts and adaptation > 410102 Ecological impacts of climate change and ecological adaptation @ 70%
SEO Codes: 19 ENVIRONMENTAL POLICY, CLIMATE CHANGE AND NATURAL HAZARDS > 1901 Adaptation to climate change > 190102 Ecosystem adaptation to climate change @ 50%
18 ENVIRONMENTAL MANAGEMENT > 1803 Fresh, ground and surface water systems and management > 180303 Fresh, ground and surface water biodiversity @ 50%
Downloads: Total: 1
Last 12 Months: 1
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page