Striped venus clam (Chamelea gallina) abundance, size, and biomass off Bevano River mouth (2019)

This dataset provides the abundance (ind. m-2) of the striped venus clams, Chamelea gallina (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 Chamelea gallina determined to the nearest 0.01 mm using a manual calliper, and the wet biomass per square metre (g m-2), 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).

Field

Darwin Core term

Unit

Precision

Note

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 <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 >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 Chamelea gallina retrieved in each sample, preserved in alcohol sorted and classified under microscope

Abundance

NA

ind. m-2

± 10

Abundance of Chamelea gallina 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 Chamelea gallina determined to the nearest 0.01 mm using a manual calliper

SDLength

NA

mm

± 0.01

Standar deviation of mean shell length of Chamelea gallina

WetMass

NA

g m-2

± 1

Wet biomass per square meter of Chamelea gallina 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).