AssetID: 53136782
Headline: RAW VIDEO: Coral Bleaching Discovered At Record Depths Sparks New Global Warming Fears
Caption: Scientists have discovered evidence of coral reef bleaching, occurring at depths exceeding 90 metres below the surface of the Indian Ocean - deeper than ever found before. This devastating phenomenon, attributed to a 30% surge in sea temperatures driven by the Indian Ocean dipole, inflicted harm upon up to 80 of the reefs in select seabed regions. Worryingly, these depths were previously believed to be resilient to the effects of ocean warming. The findings, which have been detailed in a study published in Nature Communications, were brought to light by researchers from the University of Plymouth. Dr. Phil Hosegood, Associate Professor in Physical Oceanography at the University of Plymouth and the project's lead, says, “This is an unequivocal revelation. Deeper corals were conventionally seen as impervious to ocean warming, primarily because their underwater environments are cooler than the surface and considered to be more stable. Nonetheless, this has been proven incorrect, and consequently, reefs at similar depths across the globe may be under threat from comparable climatic shifts.” The University's research efforts in the Central Indian Ocean have spanned over a decade and have received crucial support from the Garfield Weston Foundation and the Bertarelli Foundation. The research has integrated in situ monitoring, underwater robots, and satellite-derived oceanographic data to acquire a deeper understanding of the area's unique oceanography and its associated ecosystems. The initial indications of coral damage were observed during a research voyage in November 2019 when scientists used remotely operated underwater vehicles equipped with cameras to assess the coral health beneath the ocean surface. Live images from the underwater cameras were transmitted to the research vessel, unveiling the coral bleaching beneath the surface. Intriguingly, during this same period, shallow water reefs exhibited no such harm. In the ensuing months, the research team examined a wide array of data collected during the research voyage, in addition to data from satellites monitoring ocean conditions and temperatures. This analysis revealed that while surface ocean temperatures remained relatively stable during this period, temperatures beneath the surface rose significantly from 22°C to 29°C due to the deepening of the thermocline across the equatorial Indian Ocean. Clara Diaz, the study's lead author, explained, “Our findings unequivocally demonstrate that this bleaching resulted from a deepening of the thermocline. This is attributed to the regional counterpart of an El Nino, and due to climate change, these cycles of variation are intensifying. Consequently, bleaching in the deeper ocean, both in this region and elsewhere, is likely to become more frequent.” Dr. Nicola Foster, a co-author of the study, added, “Our results highlight the vulnerability of mesophotic coral ecosystems to thermal stress and provide fresh evidence of the far-reaching impacts of climate change on every corner of our ocean. Escalating bleaching in mesophotic corals will eventually lead to coral mortality and a diminution in the structural complexity of these reefs. This is likely to result in a loss of biodiversity and a decline in the vital ecosystem services that these reefs provide to our planet.” Researchers from the University returned to the same regions during scheduled voyages in 2020 and 2022, and observed significant recovery in large parts of the reef. Despite this positive development, it is crucial to intensify monitoring of the seafloor in the deep ocean, even though it presents a substantial challenge. With the frequency and severity of damage to shallow water corals increasing, there was hope that mesophotic corals, found at depths between 30-150 metres, would help compensate for the loss of these shallow corals. Nevertheless, this research suggests that this may not be the case, and the largely uncharted territory of deep-sea corals across the planet may be experiencing similar unnoticed bleaching events. Dr. Hosegood concluded, “The oceanography of the region is influenced by naturally occurring cycles that are being exacerbated by climate change. Presently, the region is grappling with comparable, if not more severe, consequences due to the combined impact of El Nino and the Indian Ocean Dipole. Although we can't prevent the deepening of the thermocline, we can expand our understanding of the consequences of these changes within these environments, which remain largely unexplored. Given the rapid pace of global change, this has never been more imperative.”
Keywords: coral,coral bleaching,oceans,nature,global warming,photo,feature,climate change,natural world
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