DOI: 10.5061/dryad.1c59zw43g
title: Local reflects global: Life-stage dependent changes in the phenology of coastal habitat use by North Sea herring

description: Climate warming is affecting the suitability and utilisation of coastal
 habitats by marine fishes around the world. Phenological changes are an
 important indicator of population responses to climate-induced changes but
 remain difficult to detect in marine fish populations. The design of
 large-scale monitoring surveys does not allow fine-grained temporal
 inference of population responses, while the responses of ecologically and
 economically important species groups such as small pelagic fish are
 particularly sensitive to temporal resolution. Here, we use the longest,
 highest-resolution time series of species composition and abundance of
 marine fishes in northern Europe to detect possible phenological shifts in
 the small pelagic North Sea herring. We detect a clear forward temporal
 shift in the phenology of nearshore habitat use by small juvenile North
 Sea herring. This forward shift can best be explained by changes in water
 temperatures in the North Sea. We find that reducing the temporal
 resolution of our data to reflect the resolution typical of larger surveys
 makes it difficult to detect phenological shifts and drastically reduces
 the effect sizes of environmental covariates such as seawater temperature.
 Our study therefore shows how local, long-term, high-resolution time
 series of fish catches are essential to understand the general
 phenological responses of marine fishes to climate warming and to define
 ecological indicators of system-level changes.
description: This data is part of the long-term NIOZ  kom-fyke monitoring
 program
 (https://www.nioz.nl/en/expertise/wadden-delta-research-centre/expertise-wadden/fish/kom-fyke-monitoring)
description: # Local reflects global: Life-stage dependent changes in the phenology of
 coastal habitat use by North Sea herring
 [https://doi.org/10.5061/dryad.1c59zw43g](https://doi.org/10.5061/dryad.1c59zw43g) This dataset contains the raw data and R-scripts used in the manuscript **Local reflects global: Life-stage dependent changes in the phenology of coastal habitat use by North Sea herring**. ## Description of the data and file structure The dataset is composed of a raw **Data ** folder and an **R-code ** folder that can be used to run the analyses presented in the manuscript. ## Data folder The **Data ** folder, contains four .csv files : * *Daily_Jetty_Data.csv - containing the local Wadden Sea water temperature time series* * *NS_temp_series.csv - containing the combined regional North Sea water temperature time series*  * *The NS_temp folder contains .csv files with the separate years of the North Sea water temperature time series, and these* *are brought together separately in the Herring_1982_2021_separate_spring_and_fall_model_code.R* * *WH_DENHDR_1982_1999.csv & WH_DENHDR_2000_2021.csv - contains the tidal data for the Marsdiep where the fyke is located*. Next to this, the **Data ** folder contains the subfolder **vanstdagen_fuiknr1 ** containing multiple fish catch data files: * *length_code_info.csv - Description of each length_code number in the datafile vanst_haring_fuiknr1.csv* * *vanst_haring_fuiknr1.csv - The raw catch data of herring in the fyke* * *vanstdagen_fuiknr1.csv -* *The amount of time (hours) the fyke was opened/operated at each catch day*. **Note: In the data files any missing column values have been filled with an "NA" value, this means no data were available for this specific variable at this specific row.** **Note: Column and variable descriptions for each separate dataset is provided in METADATA.xlsx file in the Data folder** ## R-code folder The **R code ** folder contains three separate R scripts: * *GCB_Herring_1982_2021_code.R - is the main script used to analyse the overall change in herring catch trends over time* * *Herring_1982_2021_separate_spring_and_fall_model_code. R - is a supplementary script that can be used to separately assess the spring and autumn trends* * *Model_by_is_season_structure_code.R - is a supplementary script where the seasonal term in the additive model is formulated alternatively (using the by='season') and the implications for model outcome and model fit can be assessed.*