DOI: 10.5061/dryad.g4f4qrfvd
title: Abundance, biomass and species richness of macrozoobenthos along an intertidal elevation gradient

description: Ecology aims to comprehend species distribution and its interaction with
 environmental factors, from global to local scales. While global
 environmental changes affect marine biodiversity, understanding the
 drivers at smaller scales remains crucial. Tidal flats can be found on
 most of the world’s coastlines and are particularly vulnerable to
 anthropogenic disturbances. They are important transient ecosystems
 between terrestrial and marine ecosystems and their biodiversity provides
 important ecosystem services. Owing to this unique position at the
 terrestrial-marine transition, strong environmental gradients of
 elevation, sediment composition and food availability prevail. 
 The data set contains information on macrozoobenthos abundance, biomass
 and community composition and abiotic and biotic environmental factors at
 a regional and local level at back barrier tidal flats of three
 East-Frisian islands in Germany. As environmental data elevation, mud
 content in the sediment, total organic carbon (TOC), porewater nutrients
 and Chl a are included.
description: We sampled a total of 9 transects with 27 sampling stations,
 i.e., three transects perpendicular to the island coast at each island
 comprised of three sampling stations each. Each sampling station was
 marked with a DGPS to estimate the elevation of the study plot. To cover
 the spatial and the temporal changes in the macrozoobenthos community,
 sampling took place once in spring and once in summer of 2019. At each of
 the sampling stations, we took three subsamples for macrozoobenthos with
 hand corers that had a diameter of 10 cm (0.0078
 m<sup>2</sup>) and a height of 20 cm, which were driven into
 the sediment at low tide. Samples were washed over a 500 µm sieve and
 fixated using 4%- buffered-formaldehyde solution. In
 the lab, samples were stained with rose bengal and identified to species
 level (or the lowest possible taxonomic unit). After taxonomic
 identification, abundances of each species and wet biomass were
 determined. Additionally, sediment composition, Chl
 <em>a</em>, TOC, pore water nutrients (DIN, RDP) and elevation
 were measured at the same date and sampling sites.
description: Details for the data set are provided in the README
 file. Datasets included: 
 Macrozoobenthos_wadden_sea.csv Species
 composition of macrozoobenthos Abundance of
 macrozoobenthos Biomass of macrozoobenthos
 Environmental data Site
 characteristics
description: # **Abundance, biomass and species richness of macrozoobenthos along an
 intertidal elevation gradient** This dataset contains the raw data
 associated with the manuscript "**Abundance, biomass and species
 richness of macrozoobenthos along an intertidal elevation gradient"**
 submitted to the journal *Ecology and Evolution*. Included are
 environmental and macrozoobenthos data collected from the tidal flats of
 the East Frisian islands in Germany during 2019. The study area included
 three tidal flats at Norderney, Spiekeroog, and Wangerooge, all situated
 within the Wadden Sea National Park of Lower Saxony, Southern North Sea.
 1. **Macrozoobenthos Community:** Nine transects with 27 sampling stations
 were established, comprising three transects perpendicular to the coast on
 each island, with three sampling stations per transect. These stations
 covered a depth range from the high-tide line to the middle-tide line.
 Sampling was carried out in spring and summer of 2019. At each station,
 three subsamples for macrozoobenthos were collected using hand corers with
 a diameter of 10 cm and a height of 20 cm, driven into the sediment at low
 tide. The samples were washed over a 500 µm sieve, fixed in
 4%-buffered-formaldehyde solution. 2. **Total Organic Carbon (TOC) and
 Sediment Composition:** Surface sediment samples (&lt; 2 cm depth) were
 collected from each station, freeze-dried, and ground for TOC analysis.
 Carbonates were removed using HCl desiccation, and TOC was measured using
 a CHNS-Elemental-Analyzer. Particle size distribution of the sediment was
 analyzed by dissolving samples in a 4%-sodium-polyphosphate solution and
 measuring with a laser diffraction spectrometer. The fraction of mud
 (&lt;0.063 mm) was determined in volume percent. 3. **Inorganic Nutrients
 and Primary Production:** Dissolved inorganic nutrients (reactive
 dissolved phosphate and dissolved inorganic nitrogen) were collected using
 rhizon samplers inserted 2 cm into the sediment and analyzed using an
 auto-analyzer. Chlorophyll a (Chl a) biomass was determined from sediment
 cores taken at each station. Chl *a* concentrations served as a proxy for
 total algal biomass. 4. **Site Characteristics:** Included are the
 coordinates, the data of sampling and the elevation. 5. Data that are not
 available are indicated by **NA** 6. The data can be found in the
 "macrozoobenthos_wadden_sea_2019.csv" file ***Comments and
 requests can be addressed to:*** Jana Dewenter Institute of Chemistry and
 Biology of the Marine Environment (ICBM), University of Oldenburg,
 Schleusenstraße 1, 26382 Wilhelmshaven, Germany Senckenberg am Meer,
 Department for Marine Research, Südstrand 40, 26382 Wilhelmshaven, Germany
 ## Description of the data and file
 structure The data are provided as a ".csv" file that can be
 opened with e.g with a spreadsheet software. The dataset contains the
 following information: | column | content | type/unit | explanation | |
 ------------------------ | --------------------------------- | --------- |
 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | measurementID | ID number | string | unique for each sample, consists out of abbreviration for the island (Nor =Norderney, Sp=Spiekeroog, Wang=Wangeroog), transect (TA, TB, TC), station (II, III, IV),  season (sum = summer, spr =spring) and a replicate number | | island | Norderney, Spiekeroog, Wangerooge | category | name of the three islands | | transect | A, B, C | category | total of nine transects, three at each island | | station | II, III, IV | category | each transect consists of three stations | | season | spring, summer | category | spring (sampling between 15.04.2019 and 17.05.2019) or summer (sampling between 2.07-30.07.2019) | | latitude | coordinates | | geographic location of data collection (Latitude WGS 84) | | longitude | coordinates | | geographic location of data collection (Longitude WGS 84) | | sample\_collection\_date | yyyymmdd | string | The date at which the sample was taken | | scientific\_name | species name | category | species name according to World Register of Marine Species (WoRMS) | | abundance | number of individuals | numerical | number of individuals per measurementID and scientific\_name | | biomass\_g | wet weight | g | wet weight per measurement ID and abundance (so if abundance is e.g. 3 than the weight is for three individuals) | | TOC | Total organic carbon | % | The total organic carbon in the upper 2 cm of the sediment | | elevation | elevation | AMSL | the elevation Above Mean Sea Level of the sampling station | | temperature | temperature | °C | Temperature in °C measured in the sediment at low tide | | DIN | dissolved inorganic nitrogen | μmol/L | the dissolved inorganic nitrogen in the sediment porewater | | RDP | reactive dissolved phosphate | μmol/L | the reactive dissolved phosphate  the sediment porewater | | Chl.a | Chlorophyll a biomass | μg/g dw | Chlorophyll a biomass in the sediment | | silt\_clay | mud content | volume % | The mud content in the sediment |