Coral Reefs Highlight the Key Role of Existing Biodiversity for Climate Change AdaptationNewsroom
New research on coral reefs led by the University of Southampton suggests that existing biodiversity will be essential for the successful adaptation of ecosystems to climate change.
About 25% of all marine biodiversity depends on coral reefs, the three-dimensional calcareous framework laid down by the coral animals together with their algal symbionts. Climate change, in particular increasing seawater temperatures, threatens to disrupt the functionality of this productive association with potentially devastating knock-on effects to ecosystem services that are provided by coral reefs including food supply, coastal protection, attraction of tourists and access to biopharmaceuticals.
Investigations of the symbiotic partnership between the coral host and their algal symbiont in the world’s hottest coral reef environments – the Persian/Arabian Gulf (PAG) and nearby seas – lead an international consortium of scientists to conclude that natural selection of existing biodiversity is key to facilitating rapid adaptation of coral reef ecosystems to climate change.
The novel findings by the University of Southampton (UK), KAUST (Saudi Arabia), NYUAD (UAE) and Tel Aviv University /IUI (Israel) are published this week in the world-leading journal Proceedings of the National Academy of Sciences (PNAS) from where the paper “Ancestral genetic diversity associated with the rapid spread of stress-tolerant coral symbionts in response to Holocene climate change” can be freely accessed online.
Professor Jörg Wiedenmann, head of the University of Southampton’s Coral Reef Laboratory and principal investigator of the project explains: “Corals of the PAG can survive exceptionally high salinity levels and temperatures of up to 35 degrees Celsius – conditions that would kill corals elsewhere. However, the historic climate change that created this extreme environment, left coral communities in the Middle Eastern region only less than 6000 years to adjust to the drastic changes. Therefore, these coral ecosystems are ideal model systems to understand how reefs may respond to present-day climate change.”
Dr Benjamin Hume, Postdoctoral Research Fellow at the University of Southampton and lead author of the paper, elaborates: “Using advanced molecular biological approaches, we recently discovered that corals of the Southern PAG host almost exclusively a species of symbiotic algae,
Symbiodinium thermophilum, that was new to science. This finding suggested that this algal species was essential for the survival of the PAG corals and the question arose whether Symbiodinium thermophilum was the product of rapid evolution catalysed by the challenging conditions of the PAG, or whether this symbiont originated elsewhere.”
To answer this question, the scientific team analysed close to a thousand corals along 5000 km of coastline in the PAG and adjacent seas.
(Read the full article at Phys.org)