Empirical measurements of ammonium excretion in kelp forest fishes: Effects of body size, taxonomy and trophic guild

Fishes and other consumers excrete metabolic waste products, including dissolved nutrients rich in nitrogen, which is an essential nutrient for primary production. Relatively little is known about the magnitude and variability of nutrients excreted by fishes in kelp forest ecosystems and whether consumer-derived nutrients are important for supporting kelp productivity. In this study, the supply of ammonium (NH4+) excreted by the dominant fishes (30 species representing ~85% of total fish biomass) was investigated on nearshore rocky reefs in California. Using rapid field incubations, the amount of excreted dissolved ammonium was measured as a function of body size (n = 460 individuals), and predictive models were developed relating mass to excretion rates at the family level. Mass-specific excretion rates ranged from 0.08 – 3.45 µmol·g-1·hr-1, and per capita ammonium excretion rates ranged from 5.9 – 2765 µmol·individual·hr-1. Ammonium excretion scaled with fish body mass to the ¾ power,..., To quantify rates of ammonium excretion for the dominant fish species inhabiting nearshore rocky reefs and kelp beds in central and southern California, we utilized established techniques in the field for rapid empirical estimation of consumer-derived nutrient excretion in aquatic systems. We selected a subset of 30 species, from 13 families, to represent the dominant fish species comprising California kelp forests. The selected species represented ~85% of total fish biomass, based on estimates of density and biomass from extensive underwater visual surveys conducted by the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) in central and southern California. Each fish species was assigned to one of five trophic guilds based on discrete, fixed trophic delineations (herbivore/omnivore, planktivore, micro-carnivore, macro-carnivore, and piscivore) as established in the literature. Herbivores/omnivores consist of species that consume a relatively large proportion of algae ..., , # Empirical measurements of ammonium excretion in kelp forest fishes: Effects of body size, taxonomy and trophic guild [https://doi.org/10.5061/dryad.0p2ngf29v](https://doi.org/10.5061/dryad.0p2ngf29v) ## Description of the data and file structure The data consists of experimental incubations of kelp forest fish in California, USA across 30 species and a range of body sizes, measuring ammonium excretion rates. ### Files and variables #### File: Shrestha\_kelp\_forest\_fish\_ammonium\_excretion\_all\_fish.xlsx **Description:** This data set contains measurements of ammonium excretion rates of kelp forest fishes from central and southern California. This data set contains information for every individual and species incubated to measure ammonium excretion ##### Variables * Fish_ID - Specific ID number for each fish in the data set * Region - Region in California where fish were collected (central or southern California) * Collection location-specific site where the fish were colle...鱼类与其他消费者会排泄代谢废物，其中包含富含氮的溶解态营养盐——而氮是初级生产必需的营养元素。目前对于海藻林生态系统中鱼类排泄的营养盐的总量与变化特征，以及消费者来源的营养盐是否对维持海藻生产力具有重要作用，相关认知仍较为匮乏。本研究针对加利福尼亚州近岸岩礁生境，对优势鱼类（共30种，占鱼类总生物量约85%）排泄的铵态氮（ammonium, NH4+）供给情况展开了调查。通过快速野外培养实验，我们以个体体质量为变量测定了溶解态铵态氮的排泄量（共测定460尾个体），并在科水平上构建了体质量与排泄速率的预测模型。单位体质量的铵态氮排泄速率介于0.08~3.45 µmol·g⁻¹·h⁻¹之间，而个体水平的铵态氮排泄速率则为5.9~2765 µmol·ind⁻¹·h⁻¹。铵态氮排泄速率与鱼类体质量的3/4次方呈缩放关系…… 为定量测定栖息于加利福尼亚中南部近岸岩礁与海藻床的优势鱼类的铵态氮排泄速率，本研究采用了水生系统中消费者来源营养盐排泄快速实证估算的成熟野外实验技术。我们从13个科中选取了30个物种，以代表加利福尼亚海藻林的优势鱼类类群。基于由海岸海洋跨学科研究合作组织（Partnership for Interdisciplinary Studies of Coastal Oceans, PISCO）在加利福尼亚中南部开展的大规模水下目视调查得到的密度与生物量估算数据，所选物种的总生物量占研究区域内鱼类总生物量的约85%。根据已发表文献中明确的固定营养类群划分标准，每个鱼类物种被归入5种营养功能群之一：植食性/杂食性、浮游生物食性、小型肉食性、大型肉食性以及鱼食性。其中植食性/杂食性物种指以较高比例摄食藻类的类群…… # 海藻林鱼类铵态氮排泄的实证测定：体质量、分类学与营养功能群的影响 [https://doi.org/10.5061/dryad.0p2ngf29v](https://doi.org/10.5061/dryad.0p2ngf29v) ## 数据与文件结构说明 本数据集包含美国加利福尼亚州海藻林鱼类的实验培养数据，涵盖30个物种与一系列体质量梯度，测定指标为铵态氮排泄速率。 ### 文件与变量说明 #### 文件：Shrestha_kelp_forest_fish_ammonium_excretion_all_fish.xlsx **说明：** 本数据集包含加利福尼亚中南部海藻林鱼类的铵态氮排泄速率测定数据，涵盖所有用于铵态氮排泄测定的实验个体与物种的相关信息。 ##### 变量说明 * Fish_ID：数据集中每条鱼的唯一标识编号 * Region：鱼类采集所在的加利福尼亚州区域（中加利福尼亚或南加利福尼亚） * Collection location：鱼类采集的具体采样点位，原文此处内容存在截断