The Coastal Engineering Laboratory (LIC) of the DICATECh of the Polytechnic University of Bari (Italy) maintains a place-based research program in the Mar Grande and Mar Piccolo of Taranto (a coastal system in southern Italy), providing records of hydrodynamic and water-quality measurements. This site is one of the most complex marine ecosystem models in terms of ecological, social, and economic activities. It is considered highly vulnerable for the presence of the naval base, the biggest still mill of Europe and an oil refinery. Two fixed stations have been installed, one in the Mar Grande (MG station) and another in Mar Piccolo (MP station). In the MG station constituents include wind speed and direction, air temperature and humidity, barometric pressure, net solar radiation, water salinity, water temperature, water pressure, dissolved oxygen, fluorescence, turbidity, CDOM, crude oil and refined fuels, sea currents and waves. In the MP station constituents include water temperature, sea currents and waves. We provide a summary of how these data have been collected by the research group and how they can be used to deepen understanding of the hydrodynamic structures and characteristics of the basin. The dataset is made by a total number of 14 files (Data citation 1). For MG station 4 files are available for the month of January 2015 (from 01.01.2015 to 31.01.2015) and other 4 files for the month of July 2015 (from 01.07.2015 to 31.07.2015). They are for both months: current datafile; wave datafile; meteo datafile; water quality parameters datafile. For MP station 3 files are available for the month of January 2015 (from 01.01.2015 to 31.01.2015) and other 3 files for the month of July 2015 (from 01.07.2015 to 31.07.2015). They are for both months: current datafile; wave datafile; temperature datafile. The dataset supplied in tab-delimited text format ASCII, contains timeseries of relevant meteocean variables marked up with the SeaDataNet common vocabularies from Library P01, P02 and P03 (https://vocab.seadatanet.org/search, last access: 19 February 2021, P01, P02, P03) and divided as follows: Current datafile format: Progressive data number Date (year/month/day/hour/minute) Position (Lat, lon) - SDN: P01:: MBANZZZZ: Cell of measurement with indication of its depth from surface (z=0); - SDN: P01:: LCSAAP01: cell current intensity (m/s); - SDN: P01:: LCDAAP01: cell current direction (in degree, referenced to North) Wave datafile format: Progressive data number Date (year/month/day/hour/minute) Position (Lat, lon) - SDN: P01:: GTHDAP01: Significant wave height Hs (m) - SDN: P01:: GTZHAW01: Significant wave period Ts (s); - SDN: P01:: GWMDAD01: Significant wave incoming direction (in degree, referenced to North); - SDN: P01:: MBANZZZZ: Local depth (mm); - SDN: P01:: GTDHAP01: H1/10- Average of the 1/10 highest waves; - SDN: P01:: GTAMZD01: Average wave period Tmean (s) Meteo datafile format: Progressive data number Date (year/month/day/hour/minute) Position (Lat, lon) - SDN: P01:: EGTSSS01: Average wind velocity (m/s) ; - SDN: P01:: ESSAMX01: Max wind velocity (m/s); - SDN: P01:: EGTDSS01: Wind incoming direction N (deg); - SDN: P01d:: CDTAZZ01: Air temperature (°C); - SDN: P01:: CDEWZZ01:Dew point (°C); - SDN: P01:: CAPHZZ01:Atmospheric pressure (mbar); - SDN: P01:: CHUMZZ01: Relative humidity (%). Water quality parameters datafile Progressive data number Date (year/month/day/hour/minute) Position (Lat, lon) -SDN: P01:: TEMPS901: Water Potential Temperature measured in ITS-90 degrees Celsius (°C); - SDN: P01:: CNDCST01: Conductivity (S/m); - SDN: P01:: PRESPR01: Absolute Pressure (dbar); - SDN: P01:: PSLTZZ01: Practical Salinity (PSU) using PSS78 algorithm; - SDN: P01:: SIGTPR01: Density (kg/m3); - SDN: P01:: DOXYOP01:Dissolved oxygen (ml/l); - SDN: P01:: CLSDPM01: Chlorophyll (µg/l); - SDN: P01:: CLSDPM01: Turbidity (NTU); - SDN: P01:: GP001:CDOM (RFU); - SDN: P01:: GP001: Crude oil (RFU); - SDN: P01:: GP001: Refined oil (RF Temperature datafile format: Progressive data number Date (year/month/day/hour/minute) Position (Lat, lon) - SDN: P01:: MBANZZZZ: Sensor depth (m); - SDN: P01:: TEMPS901: Water Potential Temperature measured in ITS-90 degrees Celsius (°C)

The monitoring stations were settled in the frame of the Italian Flagship Project RITMARE (Italian Research for the Sea, where we operated as the research unit Co.N.I.S.Ma.-Polytechnic University of Bari) and with funds from PON R&C 2007-13 Project (chief scientist of both Michele Mossa). The present work was partially funded by an agreement between the Polytechnic University of Bari and the Special Commissioner for urgent measures of reclamation, environmental improvements, and redevelopment of Taranto, gratefully acknowledged.