Population dynamics of oceanic manta rays (Mobula birostris) in the Raja Ampat Archipelago, West Papua, Indonesia, and the impacts of the El Niño–Southern Oscillation on their movement ecology

Using long-term photo-identification and mark–recapture modelling, this study estimated a large but climate-sensitive superpopulation of ~1,875 oceanic manta rays in Raja Ampat, with a strong female bias and generally low apparent residency at cleaning stations. Sightings increased dramatically during the 2015–2016 El Niño, driven by ENSO-related sea surface temperature anomalies that likely triggered large-scale redistribution and temporary influxes of individuals from outside Raja Ampat. These findings highlight that oceanic manta rays respond strongly to climate variability, implying that static, site-based protection alone is insufficient. Effective conservation must integrate climate-aware management, maintain protection of key aggregation sites, and reduce fisheries and bycatch risks across broader regional seascapes that mantas may use during climate-driven movements.

Authors:

Calvin S. Beale, Joshua D. Stewart, Edy Setyawan, Abraham B. Sianipar, Mark V. Erdmann

Publisher:

Diversity and Distribution

Keywords:

citizen science, climate change, conservation, demographics, marine megafauna, mobulid rays

Group Species:

Elasmobranch

Species:

Oceanic manta ray

Scale:

West Papua

Year:

2019