A hybrid is born: Integrating collective sensing, citizen science and professional monitoring of the environment.

Including members of the public in the development of effective environmental monitoring systems is gaining traction. This research assesses the potential for a hybrid monitoring system for the case of coral at the Great Barrier Reef. Based on a review of citizen-derived data sources, the paper first develops a framework and then populates it with five datasets. These are then compared based on data volumes, type of data, spatial coverage, and bleaching patterns. The results reveal the inherent difficulties – both in terms of quantity and quality – for collective sensing data (Twitter in this case) and more structured human sensors approaches (Eye on the Reef Sightings). However, more targeted approaches, such as CoralWatch and tourism-operator based data collection, emerged as important contributors to information generation on the state of coral. Citizen-based data that either deliver a high data density per location, a wide geographic coverage, or regular observations over time are particularly valuable. Recommendations are made for developing a hybrid monitoring system that integrates citizen-derived with professionally collected data. • Framework for differentiating various approaches to citizen-derived data • Comparison of five data sources for coral at the Great Barrier Reef • Collective sensing data are insufficient in quantity and quality. • Structured citizen science programs can add considerable value. • A hybrid monitoring system could greatly assist the marine park authority. [ABSTRACT FROM AUTHOR]