Review of cetacean diversity, status and threats in the Pacific Islands region 2021 (Draft 23/7/22)

This report presents a general summary of cetacean species and their threats in the Pacific Islands region. The information in this report is separated into three main sections: i) an overview of cetaceans found in the Pacific Islands region, (ii) a review of key threats for Pacific Island cetaceans, and (iii) identification of knowledge gaps in assessing threats to Pacific Island cetaceans – with particular focus on the monitoring and evaluation of risk in relation to fisheries by-catch. The report represents an update to an initial review entitled “Current state of knowledge of cetacean threats, diversity, and habitats in the Pacific Islands Region” (Miller 2007). In total, there are verified records for 34 different cetacean species across the Pacific Islands region (Table 1 and Appendix). These species vary greatly in life history characteristics, ecology, biology and habitat range.. It is also likely that many more species occur across the region yet have not been documented. Threats to Pacific Island cetaceans were summarised under broad categories of threat developed by Avila et al. (2018) that sought to (i) comprehensively review and classify global threats to cetaceans and (ii) align with the process and classification used to define threats under the IUCN status assessment process. These categories are: ● Incidental catch (by-catch) and fishing gear interactions ● Harvesting (direct take) ● Pollution ● Vessel traffic ● Pathogens and introduced species ● Resource depletion ● Ocean-physics alteration including climate change An assessment of relative risk for each of these threats was also undertaken by considering the availability of data, confidence in the available data, and relative risk of the given threat. The key cetacean species most likely impacted by the given threat has also been listed. Finally, a broad discussion of the gaps in understanding as well as recommendations for remedying and progressing some of these threats, risks and knowledge gaps is provided.