Crowdsourcing biodiversity data from recreational SCUBA divers using Dive Reporter

Monitoring spatiotemporal patterns in marine environments is crucial to ensure a better understanding of ecosystem functioning and, ultimately, for adequate management and marine conservation policies. The lack of resources required for surveys and data acquisition often hampers the availability of long-term datasets, which can be partly mitigated by leveraging citizen science and information technologies to crowdsource data. There is an inherent trade-off between the quality of data obtained using scientific and systematic protocols, and that collected by citizen scientists in an opportunistic fashion. In this pilot study, we explore crowdsourcing data from recreational SCUBA divers using a mobile app to report sightings of a predetermined list of taxa, which have been selected by regional experts as biological indicators. This approach uses post-dive queries that provide some level of standardisation, by focusing on the frequency and abundance of specific taxa, while retaining a recreational dive plan. Additionally, the app also collects metadata on location, number of dives and number of divers enabling normalisation based on “sampling effort”. In this pilot study, the use of the app was tested to compile information on the frequency and abundance of 18 marine taxa selected by local experts based on their conservation status, commercial interest, ecological function and/or their non-indigenous origin. Additionally, a question-based survey was conducted to assess the opinion of users on the app's usability and the potential value for the diving community/industry, showcasing a high usability score and interest among users. Basic statistical analysis of the data crowdsourced over the 1-month trial illustrates the potential and value of regional monitoring programs using custom lists of taxa and an app to crowdsource data from local dive centres and divers. With the ability to customise the list of taxa used in a region, monitoring programs that leverage mobile apps during post-dive interviews can provide valuable information on species occurrences in any region with active recreational dive operations. Such programs are cost-effective scalable solutions that can easily provide complementary data that can be used to monitor the proliferation of non-indigenous species, to assess the efficacy of conservation measures on protected and endangered species and to assess economically exploited species, as they can track time fluctuations and spatial variations in any conspicuous taxa that scuba divers can report.