The occurrence of the doctorfish Acanthurus chirurgus is reported for the first time in the Mediterranean Sea, off Elba Island, Tyrrhenian Sea (42.726667° N, 10.434444° E). This record is tentatively related to aquarium release. The occurrence of Acanthuridae in the Mediterranean Sea is briefly reviewed, and some distributional notes on Acanthurus coeruleus and Acanthurus monroviae in the Mediterranean are provided.

Posidonia oceanica is of particular interest in environmental studies for its ecological and economical importance in Mediterranean coastal environments. The plant is a source of direct and indirect food for marine organisms and it contributes greatly to increase the content of oxygen in the water. Grasslands of Posidonia oceanica represent a biological indicator of pollution and of the physio-chemical status of the marine environment.This paper, after recalling the main characteristics of Posidonia oceanica, discussing of its importance in the marine ecosystem, and quickly summarizing the methodology to study grasslands' evolution, propose a new methodology for collecting data by means of advances underwater technologies (acoustic localization systems, diver propulsion vehicles and photo cameras). In particular, new tools for analysis and mapping the growth areas and their physio-chemical and morphological characteristics and for construction of augmented maps for GIS using open tools like Google Earth are presented. Preliminary results concerning the population of Posidonia oceanica in the Tremiti marine sanctuary, Italy, where it colonizes large areas, are described.