IMIS

Several ROV dives in 2011 collected imagery date between 80 and 255 meters depth, extending from Monte da Guia to the circalittoral off Criação Velha in Pico Island (Gomes-Pereira et al. 2014). Benthic sessile and mobile megafauna of conspicuous morphotype, or larger than circa 10 cm, as well as all icthyofauna present, was logged on to a database with the customizable video annotation software COVER (Ifremer). The ROV SP ( SeaBotix LBV300S-6 ; IMAR-DOP/UAz), was operated from the R/L Águas Vivas. The ROV was equipped with a colour camera (570 line/02 Lux, 4:3), with four lights installed externally on the four front corners (480 Lumen each) and a scaling two-point laser system (5 cm apart) that was used to estimate sizes. ROV SP was positioned with a Subsea Micron Nav USBL (Ultra Short Baseline) unit fitted onto the vehicle in the responder mode. The navigational data were manually filtered for outliers and smoothed with a moving average, to remove false loops. The moving average allowed adjusting the resulting dive track (Gomes-Pereira and Tempera 2015).