DOI: 10.5061/dryad.s7h44j1hp
title: Brown trout 29-year dataset - Glenariffe Stream, New Zealand

description: Globally, many large rivers are modified to meet human needs, often with
 adverse impacts on fish populations. In New Zealand, such rivers support
 important recreational brown trout (Salmo trutta) fisheries, but
 understanding of river alterations on trout is limited. This study
 utilized New Zealand’s most extensive brown trout dataset from Glenariffe
 Stream (1965–1993). Annual brown trout spawning numbers varied eight-fold;
 larger runs had more small, first-time spawners, while smaller runs were
 sustained by return spawners. Spawning timing differed by sex, with larger
 fish arriving two months later than initial smaller spawners. Juvenile
 outmigration was driven by water level, time of year, and lunar phase.
 Tagged fish data highlighted the significance of longitudinal connectivity
 for post-spawning adults, particularly females, which travelled over 100
 km downstream to estuarine habitats to rapidly regain condition.
 Collectively, our findings quantify the inherent annual variability in
 brown trout spawning runs and the catchment-wide scale that brown trout
 population dynamics occur over. Managers need to understand these
 upstream-downstream linkages when making river-modification decisions.
description: # Brown trout 29-year dataset - Glenariffe Stream, New Zealand
 [https://doi.org/10.5061/dryad.s7h44j1hp](https://doi.org/10.5061/dryad.s7h44j1hp) ## Description of the data and file structure The importance of river connectivity in maintaining headwater brown trout *(Salmo trutta)* stocks in a New Zealand river – results from a 29-year study. Study authors: Phillip G. Jellyman and Donald J. Jellyman Corresponding Author: Phillip G. Jellyman, National Institute of Water and Atmospheric Research Ltd., P.O. Box 8602, Christchurch, New Zealand. Email: [phillip.jellyman@niwa.co.nz, ](mailto:phillip.jellyman@niwa.co.nz)Phone: +64 3 343 8052 Data of data collection: 1965–1993 Location of primary data collection: a counting fence across Glenariffe Stream approximately 200 m above the confluence with the Rakaia River, Canterbury, New Zealand. There are multiple datasets in this Microsoft Access Database file. These are primarily: adult salmonid trap, salmonid fry trap, tag return location and environmental data parameters. For additional queries about dataset specifics please consult the authors. ### Files and variables #### File: Glenariffe_brown_trout_database.accdb **Description:**  There are multiple datasets in this Microsoft Access Database file. These are primarily: adult salmonid trap, salmonid fry trap, tag return location and environmental data parameters. The variables from the following tables have the following units: BT_adults: FL [fork length] (mm), W [weight] (grams), Fin [fin clip]: ar = single repeat spawner, aar = multiple repeat spawner BT_fry_FL: FL [fork length] (mm) BT_frytrap: cells indicate fry count per bay Environment: Rain (daily rainfall, mm), AirMin (minimum air temperature, °C), AirMax (maximum air temperature,°C), WAbove (relative water level, cm), WMin (daily minimum water temperature, °C), WMax (daily maximum water temperature, °C), Cloud  (cloud cover was recorded in eighths), Pressure (air pressure, hPa) For additional queries about dataset specifics please consult the authors. ## Code/software N/A ## Access information Other publicly accessible locations of the data: * N/A Data was derived from the following sources: * Data are original and unpublished elsewhere