Freshwater organisms face a dual challenge in warming waters due to increased metabolic demands and declining oxygen levels. However, the relationship between temperature, oxygen, and heat-induced mortality in natural systems remains poorly understood. Here, we combine heat tolerance measurements in the laboratory with high-resolution water temperature and oxygen records in the field to predict mortality of different species under natural conditions. We demonstrate this approach in three species, one crab and two fish, of the Mapocho River in central Chile, and validated predictions with a capture-recapture experiment under natural settings. Our work unequivocally shows that current water temperatures can trigger mortality in some areas of the river and provides a robust approach to predict when heat-induced mortality is likely to occur. This approach offers a valuable tool for evaluating water quality and when river conditions may be stressful or restrictive for monitoring purposes, and to design possible mitigation strategies.

Description of the data and file structure

Our study combines heat-tolerance measurements in the laboratory with high-resolution field records of water temperature and dissolved oxygen to predict mortality of different species under natural conditions. This approach was applied to three species, one crab and two fish, of the Mapocho River in central Chile, and validated predictions with a capture-recapture experiment under natural settings. Our work shows that current water temperatures and dissolved oxygen levels trigger mortality in some areas of the river and its watershed.

Data description:

The three TDT datasets belong to the studied species used to build mortality predictions described in our manuscript. Each spreadsheet presents its respective metadata.

Crustacean: TDT_Aegla.xlsx
Fish: TDT_Gambusia.xlsx
Fish: TDT_Trichomycterus.xlsx

The main dataset is linked with experimental measurements focused on the species Aegla leavis, which contains metadata information:

Aegla_data.xlsx/dataset: The spreadsheet contains morphological, physiological, and mortality records for A. leavis collected during the experimental trial.
Aegla_data.xlsx/field PO2: The spreadsheet contains the in situ dissolved oxygen record linked to each field logger deployed during the mortality field measurements.

Water temperature records from exposed and covered areas, loggers deployed during the mortality field measurements:

Exposed logger: e1_13_02.csv
Exposed logger: e2_13_02.csv
Exposed logger: e3_13_02.csv
Non-exposed logger: ne1_13_02.csv
Non-exposed logger: ne2_13_02.csv

Annual water temperature records were obtained from a logger in the reference place:

ta_locurro_2021-2022.csv

Time series data (1966 - 2023) from DGA (Direccion General de Aguas, Chile) physicochemical records from the Maipo river basin, which contains metadata information:

Data_Env_MaipoBasin.xlsx/golden_data

Code/Software

Code to main manuscript analyses: ECOG_Analysis.R

Data from: Predicting heat mortality in freshwater communities: temperature and oxygen effects

Data files

Abstract

Description of the data and file structure

Code/Software

Data from: Predicting heat mortality in freshwater communities: temperature and oxygen effects

Data files

Abstract

README: Data from: Predicting heat mortality in freshwater communities: temperature and oxygen effects

Description of the data and file structure

Code/Software

Works referencing this dataset