This report presents a case study of how to improve the quality control and interoperability of marine spatial data, and focuses on the quality control of fish and shark annotations from baited remote underwater stereo-video (stereo-BRUV) imagery. The GlobalArchive-CheckEM service conducts a series of quality control checks on annotation data against life-history information, based on the Codes for Australian Aquatic Biota (CAAB). This report provides a ‘how-to guide’ for CheckEM and we propose that, in addition to review by expert fish ecologists, any fish and shark image annotations collected in Australia should be validated using CheckEM. Data validation, quality control and interoperability of spatial data are key to enable data discovery and re-use for biodiversity reporting and science communication. This report outlines how Findable Accessible Interoperable Reproducible (FAIR) aspects of marine data can be improved and implemented at a national scale.

Overfshing is the primary cause of marine defaunation, yet declines in and increasing extinction risks of individual species are difcult to measure, particularly for the largest predators found in the high seas. Here we calculate two well-established indicators to track progress towards Aichi Biodiversity Targets and Sustainable Development Goals: the Living Planet Index (a measure of changes in abundance aggregated from 57 abundance time-series datasets for 18 oceanic shark and ray species) and the Red List Index (a measure of change in extinction risk calculated for all 31 oceanic species of sharks and rays). We fnd that, since 1970, the global abundance of oceanic sharks and rays has declined by 71% owing to an 18-fold increase in relative fshing pressure. This depletion has increased the global extinction risk to the point at which three-quarters of the species comprising this functionally important assemblage are threatened with extinction. Strict prohibitions and precautionary science-based catch limits are urgently needed to avert population collapse, avoid the disruption of ecological functions and promote species recovery.

An annotated checklist of chondrichthyan fishes (sharks, batoids, and chimaeras) occurring in South African waters is presented. The checklist is the result of decades of research and on-going systematic revisions of the regional fauna. The chondrichthyan fauna of South Africa is one of the richest in the world with 191 species, comprising 50 families and 103 genera. It consists of 30 families, 64 genera, and 111 species of sharks; 17 families, 36 genera, and 72 species of batoids; and, 3 families, 5 genera, and 8 species of chimaeras. The most species-rich shark families are the whaler sharks Carcharhinidae with 20 species followed by the deepwater catsharks Pentanchidae with 13 species. The most speciesrich batoid families are the hardnose stakes Rajidae with at least 21 species followed by the stingrays Dasyatidae with 13 species. This monograph represents the first detailed annotated checklist of chondrichthyans from South Africa in over 30 years.