Artificial light at night and warming impact grazing rates and gonad index of the sea urchin Centrostephanus rodgersii

Artificial light at night (ALAN) is a growing threat to coastal habitats, and is likely to exacerbate the impacts of other stressors. Kelp forests are dominant habitats on temperate reefs but are declining due to ocean warming and overgrazing. We tested the independent and interactive effects of ALAN (dark vs ALAN) and warming (ambient vs warm) on grazing rates and gonad index of the sea urchin Centrostephanus rodgersii. Within these treatments, urchins were fed either ‘fresh’ kelp or ‘treated’ kelp. Treated kelp (Ecklonia radiata) was exposed to the same light and temperature combinations as urchins. We assessed photosynthetic yield, carbon and nitrogen content and C:N ratio of treated kelp to help identify potential drivers behind any effects on urchins. Grazing increased with warming and ALAN for urchins fed fresh kelp, and increased with warming for urchins fed treated kelp. Gonad index was higher in ALAN/ambient and dark/warm treatments compared to dark/ambient treatments for urchi..., Please refer to the manuscript for more information. , , # Data from: Artificial light at night and warming impact grazing rates and gonad index of the sea urchin Centrostephanus rodgersii

This README file was generated on 13-03-24 by Amelia Caley

This project is for the manuscript \"Artificial light at night and warming impact grazing rates and gonad index of the sea urchin Centrostephanus rodgersii\" from an experiment conducted in June - August 2022 in Sydney, Australia, testing the combined effects of Artificial Light at Night (ALAN, 50 lux) and warming (+ 2 degrees C) on urchin grazing rates and gonad index, kelp photosynthetic yield and C and N content, and on trophic interactions between urchins and kelp. The file called \"Urchins ALAN Final\" is the original dataset created during the experiment. This file can be imported for use with the original code, or the cleaned, long format dataset (created within this code) can be used. Photosynthetic yield, urchin gonad index and urchin grazing rates are visualised and modelled in the Urchin AL...

夜间人工光（Artificial Light at Night, ALAN）正对沿海栖息地构成日益严峻的威胁，并可能加剧其他环境胁迫因子的负面影响。温带礁域的优势生境为海带林，但受海洋变暖与过度牧食的双重影响，其面积正持续缩减。本研究针对夜间人工光（设置黑暗与ALAN两个对照组）与海洋增温（设置环境温度与升温两个对照组）对长刺海胆（Centrostephanus rodgersii）的摄食率及生殖腺指数的独立与交互效应开展了实验探究。实验中海胆分别喂食“新鲜”海带与“处理后”海带，其中处理后的澳洲大叶藻（Ecklonia radiata）与海胆处于完全一致的光温条件下。我们测定了处理后海带的光合产量、碳氮含量及碳氮比，以明确影响海胆相关生理指标的潜在驱动因素。实验结果表明：喂食新鲜海带的海胆，其摄食率随增温和ALAN暴露程度升高而提升；喂食处理后海带的海胆，摄食率则仅随增温而提升。相较于黑暗/环境温度组，ALAN/环境温度与黑暗/增温组海胆的生殖腺指数更高……更多详细信息请参阅研究手稿。

# 数据来源：《夜间人工光与增温对长刺海胆Centrostephanus rodgersii摄食率及生殖腺指数的影响》
本说明文件于2024年3月13日由Amelia Caley生成。
本项目对应研究手稿《夜间人工光与增温对长刺海胆Centrostephanus rodgersii摄食率及生殖腺指数的影响》，相关实验于2022年6月至8月在澳大利亚悉尼开展，旨在探究夜间人工光（光照强度设置为50 lux）与增温（升温2℃）对海胆摄食率、生殖腺指数，海带光合产量、碳氮含量，以及海胆与海带间的营养级互作的联合效应。名为“Urchins ALAN Final”的文件为实验期间生成的原始数据集，可配合原始代码导入使用，也可使用本代码中生成的已清洗长格式数据集。本研究对光合产量、海胆生殖腺指数及海胆摄食率进行了可视化分析与建模，相关内容见于《Urchin AL...》