DOI: 10.5281/zenodo.7990369
title: Striped venus clam (Chamelea gallina) abundance, size, and biomass off Bevano River mouth (2019)

description: This dataset provides the abundance (ind. m<sup>-2</sup>) of the striped venus clams, <em>Chamelea gallina</em> (Linnaeus, 1758), at 71 random sampling points (Fig. 3) from 0.5 to 8 m depth along the coast (5 km) off the NATURA 2000 site IT4070009 "Ortazzo, Ortazzino e Foce del Torrente Bevano", sampled from 22 May to 4 July, 2019. Where available, the mean and standard deviation of shell length (i.e. the maximum distance between anterior and posterior margins) of <em>Chamelea gallina </em>determined to the nearest 0.01 mm using a manual calliper, and the wet biomass per square metre (g m<sup>-2</sup>), estimated on the basis of the mean shell length, by length–weight relationship (according to Petetta et al., 2019), were provided. Depth, sediment grain size, and organic matter at each point are also provided. The dataset is provided in three formats: Microsoft Excel XLSX file, including 3 sheets (Dataset, Fields and units, Parameters) CSV files (UTF-8), 3 files corresponding to the 3 sheets of the Excel file ESRI Shapefile (UTF-8, geometry point, EPSG:4326 - WGS 84) The dataset includes 71 records, one for each sampling point, and 17 fields, which are described in the Excel sheet/CSV file “Fields and units” (see also Table 6). The Excel sheet/CSV file provides details and coefficients of the length–weight relationship (log W= log a + b log L; where: W=wet weight (g), L=length (mm), Log base=10) used to estimate the wet biomass from the mean lengths and abundances (the calculation formulas are present in the Excel sheet). Finally, ESRI Shapefile provides users with direct upload in any Geographic Information System (GIS). Nevertheless, due to this file format limitations, dataset field names have been truncated and/or renamed to fit 10 characters. Fields in the dataset (NA=not available). <strong>Field</strong> <strong>Darwin Core term</strong> <strong>Unit</strong> <strong>Precision</strong> <strong>Note</strong> locationID locationID NA NA Sampling location identifier (ID) specific to the data set samplingDate eventDate YYYY-MM-DD NA Conforms to ISO 8601-1:2019 samplingTime eventTime HH:MM ± 10 min Central European Summer Time CEST (UTC+2) conforms to ISO 8601-1:2019 decimalLatitude decimalLatitude decimal degrees ± 0.00001 WGS84 (EPSG: 4326) - WAAS/EGNOS enabled GPS position decimalLongitude decimalLongitude decimal degrees ± 0.00001 WGS84 (EPSG: 4326) - WAAS/EGNOS enabled GPS position Depth maximumDepthInMeters m ± 0.1 Mean Lower Low Water - measured with echosounder or depth gauge corrected by tide gauge of Porto Corsini (RA) SamplingGear NA NA NA Van Veen grab operated from boat or bailer manually operated by diver inside a cylindrical frame SamplingArea NA m2 ± 0.001 Sampler size Mud NA % dry mass ± 0.1% Sediment particles &lt;63 µ wet sieved recovered on Whatman filter paper and then dried at 80°C for 24 hours before weighing at ± 0.00001 g FineSand NA % dry mass ± 0.1% Sediment particles 250-63 µ wet sieved recovered on Whatman filter paper and then dried at 80°C for 24 hours before weighing at ± 0.00001 g MediumSand NA % dry mass ± 0.1% Sediment particles &gt;250 µ wet sieved recovered on Whatman filter paper and then dried at 80°C for 24 hours before weighing at ± 0.00001 g OrganicMatter NA % dry mass ± 0.1% Sediment organic matter content obtained by Loss of weight on Ignition (LOI%) at 450°C 8h and weighted at ± 0.00001 g Individuals NA ind. sample-1 ± 1 Individuals of <em>Chamelea gallina </em>retrieved in each sample, preserved in alcohol sorted and classified under microscope Abundance NA ind. m-2 ± 10 Abundance of <em>Chamelea gallina</em> per square meter estimated on the basis of the sampling area MeanLength NA mm ± 0.01 Mean shell length (i.e. the maximum distance between anterior and posterior margins) of <em>Chamelea gallina</em> determined to the nearest 0.01 mm using a manual calliper SDLength NA mm ± 0.01 Standar deviation of mean shell length of <em>Chamelea gallina</em> WetMass NA g m-2 ± 1 Wet biomass per square meter of <em>Chamelea gallina</em> estimated on the basis of the mean shell length, by length–weight relationship (according to Petetta et al., 2019 DOI:10.1080/24750263.2019.1668066), and abundnce This dataset comes from the project "Characterization of the mouth area of the Bevano River and identification of strategies for the conservation and enhancement of nursery areas for protected species of commercial interest", carried out by the Interdepartmental Research Center for Environmental Sciences (CIRSA) of the Alma Mater Studiorum University of Bologna. The project was financed by the Emilia-Romagna Region (call FLAG Costa dell'Emilia-Romagna 2018) with funds from the European Union (FEAMP 2014/2020, Action 2.A.a, "Marine and lagoon habitats - Studies and research"), and took place from January to August 2019 (Abbiati et al., 2019). Finally, this dataset has been revised and completed within the project “Ecosystem for Sustainable Transition in Emilia-Romagna” (ECOSISTER, Code: ECS_00000033 - CUP: B33D21019790006).