Posidonia oceanica (L.) Delile meadows represent priority habitat according to the European Union Habitats Directive. In Croatia they are legally protected habitats. Meadows are located in the shallow coastal areas under the threat of numerous human activities. Recently, aerial photos of the Croatian part of the Adriatic have revealed several locations of circular damage to Posidonia meadows extending back in time over a decade. In some locations these circles exist as a regular linear series on remote island shores, and at other locations they appear haphazardly positioned and sometimes overlapping. The aim of this study was to determine the area and characteristics of this circular damage, and whether they belong to a particular group considering the size, depth, and distance from human settlements. Publicly available internet browsers, ARKOD and “Google Earth”, were used to view and inventory the circular pattern damage in Posidonia meadows. We detected 476 damage circles along the Croatian coast of the Adriatic, and 117 of them form regular series. For those 15 series we conducted the basic descriptive statistics. The results indicate that the occurrence of damage is likely caused by the influence of a variety of human activities, which might be associated with underwater explosions.