exp_number  month  year  species                      
1           June   2018  Thalassiosira_weissflogii    
2           July   2018  Thalassiosira_weissflogii    
3           Sept   2019  Thalassiosira_weissflogii    
4           Oct    2019  Skeletonema_marinoi          
5           Nov    2019  Thalassiosira_weissflogii    
6           Dec    2019  Skeletonema_marinoi