Application of a long-range camera to monitor fishing effort on an offshore artificial reef

Abstract

A land-based long-range camera was developed and tested at an artificial reef site in south-east (SE) Australia to monitor levels of recreational fishing effort across a range of 9 km. The camera had 50x magnification and was operated remotely through a 4 G-LTE network, including the ability to focus and program time intervals between images. The camera was powered by a 12 V system charged through 3 × 180 W solar panels. The camera was tested over an 8-month period where photographs were taken every 15 min during daylight hours, imagery taken at this time was used to estimate fishing effort (vessel hours day−1). The long-range camera was successful in producing photographs of boats fishing on the artificial reef across the 9 km range. This capability was ground-truthed by placing a research vessel on the reef at known times and cross referencing this in photographs taken during these periods. Camera performance did diminish at times during the first few hours after sunlight, particularly during the warmer months, this was most likely caused by atmospheric turbulence occurring across the 9 km range. Although not the primary focus of the study, it was found that fishing effort at the study site varied between weekdays and weekends, with increased activity occurring during the latter. The long-range camera is likely useful beyond monitoring artificial reefs and would provide opportunities for monitoring offshore infrastructure such as aquaculture leases, or fishing effort in marine protected areas.