Monitoring biodiversity with a wired underwater camera
Monitoring marine life and its biodiversity requires technological implementation to achieve the standards required for advanced ecosystem management in Marine Protected Areas (MPAs). We chose the Krka River Estuary Natura 2000 site in Croatia as a pilot area. A wired underwater surveillance camera is positioned at 5 m depth. The image acquisition is based on a motion sensing method with a self-developed software (“Fish Monitoring”) running on a Windows OS environment. The images of mobile megafauna taken during daylight hours from 10th January to the end of April 2018 were selected for further processing. A total of 13808 images were analysed from which 136195 individual animals were identified. From 10026 images, a total of 16216 fish specimens belonging to 35 species were identified. These included 24 species of commercial interest, including the billfish Thunnus thynnus (Atlantic bluefin tuna) and animals of conservation interest such as the loggerhead turtle, Caretta caretta. The data collected in the time series showed an increase of fish biodiversity from winter to spring.