Marine macrobenthic assemblages off Lido di Dante beach (2020)

This dataset provides the abundance (ind. m-2) of marine macrobenthic invertebrate species at 20 random sampling points in a square area of about 400×400 m from 0.8 to 5.0 m depth, along a beach without bathing establishments at Lido di Dante, an Emilia-Romagna coastal locality in the Ravenna municipality (Fig. 11), manually sampled on October 8th, 2020. 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, Taxonomy)

- 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 20 records, one for each sampling point, and 137 fields (consistent with the other project macrobenthic datasets: Riccione, DOI: 10.5281/zenodo.10592392, and Bevano, DOI: 10.5281/zenodo.10592458). The first 14 fields are described in Table 15. The subsequent fields concern the abundance of the identified taxa as individuals preserved in alcohol sorted and classified under microscope (ind. m-2 ± 20). All the dataset fields are described in the Excel sheet/CSV file “Fields and units”, while the taxonomic related information for each taxon is provided in the Excel sheet/CSV file “Taxonomy”. Information extracted from the World Register of Marine Species (WoRMS; https://marinespecies.org/) is provided here (see details in Table 16). 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.

Figure 11. Map of the study area showing the 20 sampling points (Basemap: Google satellite; Projection WGS84 / UTM 33N, EPSG:32633).

Table 15. First 14 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

X_UTM33WGS84

NA

m

± 1

WGS 84 / UTM zone 33N (EPSG:32633) - WAAS/EGNOS enabled GPS position

Y_UTM33WGS84

NA

m

± 1

WGS 84 / UTM zone 33N (EPSG:32633) - WAAS/EGNOS enabled GPS position

Depth

maximumDepthInMeters

m

± 0.1

Mean Sea Level (MSL, Genova zero) - measured with echo sounder and corrected by the closer tide gauge (in the area MSL is about +0.40 MLLW)

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

Table 16. Provided taxonomic information.

Taxon

the name used in the dataset

AphiaID_accepted

unique identifier in WoRMS

ScientificName_accepted

the name accepted according WoRMS

Authority_accepted

the name of the scientist or scientists who first validly published the name

Kingdom

Taxonomic level

Phylum

Taxonomic level

Class

Taxonomic level

Order

Taxonomic level

Family

Taxonomic level

Genus

Taxonomic level

Subgenus

Taxonomic level

Species

Taxonomic level

Lido di Dante is a small seaside village in the North Adriatic, 7 km from the city of Ravenna, in the area delimited by the mouths of the rivers Fiumi Uniti to the north and Bevano to the south. The two drainage basins of the rivers have very different dimensions and characteristics: the Fiumi Uniti basin is much larger and contains an important mountainous part which contributes a notable quantity of sediments, while the Bevano river is essentially a natural drainage channel of the plain with negligible sediment transport.

The sandy beach of Lido di Dante has a concave shape and is more than 2.5 km long, it can be divided into two parts: the north beach, almost 600 m long, subject to strong erosion and therefore protected by groins, nourishment and a semi-submerged breakwater and the southern beach which has undergone only slight erosion and is in a natural state. It has a tidal range between 0.30 m and 0.85 m, a gentle slope of the seabed, a large surf zone exposed to winds blowing from the south-east in summer and from the north-east in winter and bottom sediments ranging from fine to medium well-sorted sand.

To date, the low transport rates of river sediments and anthropic and natural subsidence have caused the recession of the coastline; furthermore, dune erosion and land subsidence, together with the construction of tourist facilities, have altered and partially destroyed the marine pine forests behind the dunes and caused the balance of the beach to be disrupted. For this reason, the protection of the coast of Lido di Dante was of primary importance and supported by the application of several subsequent interventions aimed at stopping the retreat of the coastline which became relevant around 1960. In fact, the first works were carried out in 1978, when a single structure was built to retain the transport of sediments due to coastal drift. In 1983, two more groins were built south of the previous one and placed 300 m apart from each other. In 1996, the current limestone rock barrier was built parallel to the coast, 180 meters from the shoreline and with a length of 770 m and, at the same time, a nourishment of 74,400 m3 of sand was implemented. The authorities also carried out large-scale nourishment in May 2007 which affected both the beach within the protection works and the one immediately to the south, the area of our interest, using sediments from offshore deposits.

Here, sampling of the benthic fauna present on the seabed in October 2020 allowed the identification of 76 taxa. The most abundant species were the Lentidium mediterraneum bivalves (on average 4465 ind. m-2). The Chamelea gallina clam, a bivalve of great commercial interest, was less abundant compared to other coastal areas in the region (109 ind. m-2).

Related Project: TAO (Tecnologie per il monitorAggio cOstiero) project, concerning innovation in shallow-water coastal monitoring (POR FESR 2014-2020 ASSE 1 AZIONE 1.2.2 PROGETTO CUP E31F18001030007; June 2019 - May 2021).