58-11 Coral Triangle Reef Diversity in the Past and Present

Session: Future Leaders in Paleontology

Presenting Author:

Katherine Faulkner

Authors:

Faulkner, Katherine¹, Versteeg, Melissa², Buckland, Victoria³, Johnson, Kenneth G.⁴, Rueger, Theresa⁵, Saupe, Erin⁶, Santodomingo, Nadia⁷

(1) Earth Sciences, University of Oxford, Oxford, United Kingdom, (2) School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom, (3) Earth Sciences, University of Oxford, Oxford, United Kingdom, (4) Natural History Museum, London, London, United Kingdom, (5) Cognition, Behaviour and Evolution, Newcastle University, Newcastle upon Tyne, United Kingdom, (6) Earth Sciences, University of Oxford, Oxford, United Kingdom, (7) Senckenberk Naturmuseum, Frankfurt, Germany,

Abstract:

The Coral Triangle in the Indo-West Pacific (IWP) is the largest marine biodiversity hotspot in the world, and it currently houses the highest abundance of coral species. Despite an increase in ocean warming over the last thirty years, IWP coral cover has remained remarkably stable. This resilience may, in part, be due to these coral communities originating in turbid waters. Water turbidity measures the amount of dissolved organic and inorganic particles, and previous work suggests these low-light conditions have been present since at least the Miocene. To better understand the original environment of the IWP, the first chapter of this Ph.D. project describes over 1,200 Oligocene scleractinian corals from eastern Sabah, Malaysia. These corals originally resided in fine silt and clay carbonate deposits, and the high diversity of these fossils provides support for some coral communities in the IWP having adapted to and evolved in turbid waters over the last 27-million years. This is the oldest-known record of such high coral diversity in the IWP, suggesting the biodiversity hotspot may have originated in shallow turbid waters. Previous research found these water conditions to reduce the effects of ocean warming on coral communities, which may explain current coral cover resilience in the Coral Triangle. To test this, the second chapter of this Ph.D. project examines the interactions between water turbidity and coral cover in the IWP during the 2023 global coral bleaching event. Video transects of coral reefs and light-level measurements were recorded from March to June 2023 in Kimbe Bay, Papua New Guinea. We recorded coral, sponge, and algal cover in both turbid and non-turbid coral reefs from March to June 2023 using the AI program CoralNet. We expect to find more stable coral cover in localities with higher water turbidity compared to more euphotic conditions. Quantifying modern-day coral cover in the IWP will provide insights into turbid reef dynamics at a local level, which can be compared to non-turbid corals in other IWP localities. These projects are significant for marine conservation, as they provide crucial information about the vulnerability and resilience of the Coral Triangle reef ecosystem.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-8667

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