Standardised methods of survey design, data collection, analysis and reporting are essential to monitoring both the status and change in Australia’s vast benthic marine environment. Efficient management of a given area requires first establishing a baseline of the key biota, and then regularly monitoring their status to detect changes over time. Changes to the diversity and abundance of benthic organisms and communities are commonly used ecological metrics in marine imagery because epibenthos is considered to be functionally important and sensitive to human activities (Williams et al. 2015). Although repeated presence-absence surveys for occupancy estimation or changes in benthic community composition can be achieved using towed camera systems, returning to a precise geographical location for a particular monitoring purpose (e.g. Bridge et al. 2014, Ferrari et al. 2016, Pizarro et al. 2017) requires an alternate sampling platform entirely (e.g. AUV in Chapter 4). However, despite known biases and limitations (e.g. Jones et al. 2009, Katsanevakis et al. 2012, Durden et al. 2016a, Durden et al. 2016b), towed camera systems are anticipated to play an important role in future monitoring strategies, and have been identified as one of the sampling methods capable of monitoring the indicators associated with shelf reef systems (Hayes et al. 2015).

The application of towed underwater camera systems to environmental monitoring involves several key steps. These include survey design (Chapter 2), pre-survey preparations, field implementation (e.g. image acquisition and onboard data storage and description), and post-survey procedures (e.g. processing of imagery for data extraction, image annotation, statistical analyses of extracted data and data release). A brief overview of these fundamental steps is provided below.