Oral Presentation Freshwater Sciences 2023

Quantifying spatial and temporal variation in fish health indicators in response to hydro-ecological disturbances. (#488)

Max C Mallett 1 , Gavin L Butler 2 , Jason D Thiem 3 , Luke Carpenter-Bundhoo 1 , Mark J Kennard 1
  1. Australian Rivers Institute, Griffith University, Brisbane, Queensland, Australia
  2. Department of Primary Industries, Fisheries, Grafton Fisheries Centre, New South Whales, Australia
  3. Department of Primary Industries, Fisheries, Narrandera Fisheries Centre, New South Whales, Australia

An emerging ecological discipline, ‘conservation physiology’, seeks to understand mechanistic links between individual fish health and anthropogenic disturbances. Assessments of fish health commonly include indicators describing energetic status (condition), key physiological functions, external abnormalities and parasite loads. The use of these indicators for quantifying aspects of fish health and responses to hydro-ecological disturbances such as anthropogenic flow alteration and land-use changes remains uncertain. This talk presents the results of a desktop analysis of an extensive dataset of sampling records within the Murray-Darling Basin. The desktop analysis aims to determine if commonly collected fish health indicators such as length-weight condition metrics and external parasite loads can be used to quantify temporal and spatial trends in fish health in response to anthropogenic hydro-ecological disturbances. Specifically, this analysis aims to address the following questions: (1) Are spatial and temporal differences in body condition related to gradients of catchment and flow regime disturbance?; (2) How does parasite load or other visual health abnormalities co-vary with fish condition and anthropogenic disturbance intensity? Understanding the spatial and temporal relationships between anthropogenic hydro-ecological disturbances and fish health will inform the way in which management interventions targeted at improving fish health could benefit population-level demographics and overall species persistence.