In this document, the harmful effects and consequences that occur on the body of tunas after the tagging process are analyzed. All the photographic and audiovisual material obtained in the tropical tuna tagging campaigns, carried out by the staff of the Canary Islands Oceanographic Center in the years 2016 (08/25/11/2016) and 2018 (06/10-28/10/2016), is analyzed. The eyes and caudal peduncle of tunas are the parts most damaged during the tagging process. It is discussed about bodily damage and possible improvements in the handling of tunas for an improvement in survival rates and a decrease in mortality after the tagging process
