READ ME File For 'DATASET’ The impact of reintroduced Eurasian beaver (Castor fiber) dams on the upstream movement of brown trout (Salmo trutta) in upland areas of Great Britain
Dataset DOI: https://doi.org/10.5258/SOTON/D3293
ReadMe Authors: Robert J. Needham, Richard W. Zabel, Dylan Roberts, Paul S. Kemp.
This dataset supports the publication: Robert J. Needham, Richard W. Zabel, Dylan Roberts, Paul S. Kemp. (2024). The impact of reintroduced Eurasian beaver (Castor fiber) dams on the upstream movement of brown trout (Salmo trutta) in upland areas of Great Britain. Plos One.
Corresponding Author: Robert Needham, Beaver Trust, 61 Bridge Street, Knighton, Hereford,  (Email: rob@beavertrust.org)
Description: The excel files contains all data used for generating Fig.2 to Fig.10.  The figures are as follows:
Fig. 2. Coarse resolution rainfall and discharge data from a nearby river. Coarse resolution environmental data of mean [± SE] daily rainfall obtained from the Lentran Meteorological station and mean [± SE] daily river discharge for the river Enrick at Mill of Tore (NH4504429976, ~ 14km southwest of study site) for the Monitoring Period (October - December inclusive) from 2006 – 2020. Rainfall data is missing for October and November 2007 and December 2010 and 2017. (Gauging Station Data.xlsx)
Fig. 3. Environmental data for the Monitoring periods in 2015 and 2016. Environmental data for the Allt Coire an t- Seilich (beaver modified) and Allt a’ Choilich (control) streams in Inverness-shire collected during the Monitoring Period (October – December inclusive), 2015 and 2016. The study investigated the influence of beaver dams on the spawning migration of brown trout. Solid, dot-dashed, dashed and dotted lines denote the daily means for rainfall, ambient air temperature, modified stream water temperature (based on an average of all four data loggers), and control stream water temperature, respectively. (Rain Temp Data 2015_2016.xlsx)
Fig. 4. Movements of an individual PIT tagged trout. Movement patterns of an individual trout over an ~ca 10-hour period (between 18:22 on 25 October and 04:32 on 26 October 2016) exhibiting ‘abnormal’ movement patterns. Columns bordered by the dashed lines A, B and F represent ‘feasible’ movements in which the fish likely used the by-pass channels resulting in detection (circles on the solid black line) at antennas 1 and 3 (but missing antenna 2), and 5 and 7 (missing antenna 6 at Dam 3). Grey columns illustrate ‘abnormal’ behaviour when multiple dams appear to have been passed with the absence of detection at multiple antennas indicative of overland movements. The PIT tag of this individual was subsequently found on the bank of the modified stream using a handheld PIT antenna suggesting otter predation. Detection Event denotes each time the PIT tag was detected during the ~ca 10 hr period. (Movement Patterns PIT ID 223.xlsx)
Fig. 5. Movement patterns of six individual brown trout. Movement patterns of six individual brown trout during the 2015 Monitoring Period demonstrating the different behaviours observed for individuals in the modified stream and how they were grouped into one of six categories: (1) Directional, (2) Exploratory Directional, (3) Drifter, (4) Resident Drifter, (5) Static and (6) Resident Static. Location of beaver dams are illustrated in relation to antenna locations with zero representing the Loch. (Movement Categories Examples.xlsx)
Fig. 6. Kaplan Meier plots for all four beaver dams. Kaplan Meier plots for all four dams with data from 2015 and 2016 combined due to small dataset from 2016. The solid lines represent estimated proportion remaining in front of the dam, and the dashed lines represent 95% confidence intervals. In the legend, total refers to total number of fish tagged, repeats are the number of repeat passers, and censored is the number of fish that were never detected passing the dam. (Survival Analysis 2015.xlsx and Survival Analysis 2016.xlsx)
Fig. 7. Covariate parameter estimates. Covariate parameter estimates (b coefficients) for water temperature, rainfall, rainfall with 24 hr lag applied, fish mass, fish length and repeat passers. Open points represent parameter estimates and vertical lines represent ± 2*(SE). If the vertical line does not intersect with zero, that provides evidence that the effect of the covariate is significant.(Survival Analysis 2015.xlsx and Survival Analysis 2016.xlsx)
Fig. 8. Passage prediction plots. Passage prediction plots for: (1) fish that passed a dam for their first time and for fish that had already passed a dam, and (2) fish with fork length of 100 mm vs fish with fork lengths of 300 mm.  The solid and dashed lines represent estimated proportion remaining, and the grey areas represent 95% prediction intervals. (Survival Analysis 2015.xlsx and Survival Analysis 2016.xlsx)
Fig. 9. Mean swimming speed (m min-1) between beaver dams. Mean swimming speed (m min-1) between Dams 1 - 2, 2 - 3 and 3 - 4 for each movement category including ‘Directional’ [black bars], ‘Exploratory Directional’ [light grey bars], ‘Drifter’ [white bars] and ‘Resident Drifter’ [dark grey bars]. Error bars denote standard deviation. (Swimming Speeds between Dams.xlsx)
Fig. 10. Mean [± SD] fork length of trout for each movement category. Mean [± SD] fork length of trout captured from the Loch, Modified stream and the control stream, for each movement category. Error bars denote standard deviation. (Motivation vs Size 2015.xlsx)
Geographic location of data collection: Beauly, Inverness, Scotland, U.K.
Date of data collection 2014-09-01 to 2016-12-30
Associated Grants: The PhD was funded by the NERC Doctoral Training Partnership (SPITFIRE) based at the University of Southampton. Additional funding was provided by the Game and Wildlife Conservation Trust, Trout and Salmon Association and NatureScot.
Dataset available under a CC BY 4.0 licence
Publisher: University of Southampton, U.K.
Date: December 2024