DOI: 10.5281/zenodo.10605243
title: European eel (Anguilla anguilla) recruitment in Comacchio lagoon (Italy) data

description: This dataset was managed for the aims of the project ECOSISTER (Ecosystem for Sustainable Transition in Emilia-Romagna), WP3 of Spoke 5 and provides information about the captured glass eels entering in the Comacchio Lagoon (NE Italy), one of the most important coastal wetlands in Europe for biodiversity conservation and one of the most important places for eels fishery. To capture glass eels entering in the Comacchio Lagoon, four sampling sites (Foce, Bellocchio, Gobbino and Passo Pedone sites were selected at gateways or canals, which directly connect the lagoon to the sea. Environmental and meteorological variables  are also provided.

 The dataset is provided in two 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

The dataset includes 59 CPUE data for different sampling dates and sampling locations. Glass eels sampling was performed from 19/01/2011 to 7/4/2011.

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 2).

Table 1. Fields in the dataset (NA=not available).








Field



Darwin Core term



Unit



Precision



Note





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





dateIdentified



dateIdentified



DD/MM/YY



NA 



The date on which the sampling was performed





SamplingGear



NA



NA



NA



a modified fyke net (called “cogollo”)





CPUE



organismQuantity



CPUE, based on number of netlifts



NA



Number of individuals caught per fyke net per day





Cond



measurementType



mS/cm



NA



Conducibility of the water





DO



measurementType



mg/l



NA



Dissolved oxygen





pH



measurementType



NA



NA



pH





Salinity



measurementType



ppt



NA



Salinity





Temp



measurementType



°C



NA



Water temperature





Wind_Prev



measurementType



NA



NA



Prevailing wind direction





MoonPh



measurementType



%



NA



Percentage of the illuminated moon disk






 

Table 2. Provided taxonomic information.

 








Taxon



the name used in the dataset





ScientificName_accepted



the name accepted according WoRMS





AphiaID



Unique identifier in WoRMS





Kingdom



Taxonomic level





Phylum



Taxonomic level





Class



Taxonomic level





Order



Taxonomic level





Family



Taxonomic level





Genus



Taxonomic level





Species



Taxonomic level






This dataset permitted the analysis of glass eel recruitment in the Comacchio lagoon through the publication of Lanzoni, M., Gavioli, A., Castaldelli, G., Aschonitis, V., Milardi, M. (2022). Swoon over the moon: The influence of environmental factors on glass eels entering Mediterranean coastal lagoons. Estuarine, Coastal and Shelf Science 264 (2022) 107668. https://doi.org/10.1016/j.ecss.2021.107668.

This dataset is the unique dataset in the Adriatic Sea, and thus along the cost of Emilia-Romagna region, providing temporal and spatial information about glass eel recruitment.

The data can help promoting eel stocks restoration through local management. For example, from the data, it was evident that glass eel migration peaked in two period and which temporal and water quality variables affected body size of glass eels, with bigger glass eels caught later in the season.

Furthermore, the dataset included information of one of the most important areas for conservation. In fact, the Comacchio lagoon is included in the 2000 Nature network as IT4060002 “Valli di Comacchio” site and also in the Ramsar convention as important wetlands. Finally, the Anguilla anguilla species is critically endangered, according to the IUCN, and is included in the 92/43/EEC Directive. Therefore, information on its current population status is necessary.