The present dataset includes diverse information on individual traits and population parameters from a mussel population in a bathymetric gradient and with monthly frequency (from March 2019 to February 2020) from two rocky shores at Le Petit Minou, France (lon: -4.615860; lat: 48.339118). Each of the two shores was at the East and West side of the Le Petit Minou beach. Sampling was carried out on a triplicate quadrat from each rocky shore. The present dataset includes all the raw data from these quadrat samples as well as derived information. 

“Length_data.csv” table includes: 36670 measures of shell length from all living individuals in each sample

“Biometry_data.csv” includes the biometric measures from 10 individuals from each sample (n total = 720 individuals), including: total weight, flesh wet weight, dry flesh weight, shell wet weight, shell dry weight, shell length, and condition index (Flesh Dry Weight / Shell Length3)

“Samples_summary.csv” includes: the geographic coordinates, bathymetric position, eastness and northness orientation of quadrats and the raw data including the number of counted individuals, number of recruits (shell length < 1.07mm), number of non-recruits (shell length >1.07mm), observed covered area, proportion of covered area inside the quadrat, and crowding index (observed covered area/sum of individuals basal area) and the population parameters expressed per meter square of a fully covered area, including total density of individuals, density of non-recruits, density of recruits, median length of individuals, median length of non-recruits individuals, maximum length of individuals, total biomass. 

All individual traits and population parameters are associated with their corresponding shore, date and replica, which is also represented by a Sample_ID, e.g., 2019.3ER1, where 2019 is the year, 3 is the month (March), E is the shore (East) and R1 is the replica number (1 out of 3).