Nav: Home

No refuge in the deep for shallow reef ecosystems

July 19, 2018

Deep water coral reefs are not the places of refuge for shallow reef organisms that some scientists have considered them to be, a new report suggests. Instead, concludes this report - based on one of the largest-ever datasets of deep coral reef visual surveys in the world - deep water coral reefs are distinct habitats, susceptible to the same natural and human impacts, and in as much need of protection as their critically endangered shallow-water counterparts. In fact, measures to protect deeper ecosystems should be prioritized in environmental policy for global marine conservation, the authors say. Coral reefs are amongst the most endangered ecosystems on the planet, suffering catastrophic damage due to human-driven climate change and habitat destruction. Deeper, mesophotic coral reefs, lying at depths between 50 and 150 meters, have been widely thought of as less vulnerable to these impacts, and further, as being capable of providing potential refuge for threatened reef species in shallower waters. This understanding is based largely on the analysis of reported depth ranges for species that could inhabit both shallow and deep reefs. However, this method offers a limited and perhaps misleading view of the overlap and connectivity between shallow and deep populations, according to Luiz Rocha et al. Rocha and colleagues re-evaluated the potential refuge role of deep water reefs through in-situ underwater observations of fish made during dozens of technical and deep-water dives on reefs in the Atlantic and Pacific Oceans. Their results show that mesophotic reefs are home to their own independent communities, with very little species overlap between depth zones. Furthermore, the effects of natural and human impacts throughout the deep reefs were documented - from storm and fishing damage to coral bleaching and plastic pollution. Rocha et al.'s study suggests that the potential for deep reefs to act as refuges is far less than thought, and reef conservation efforts should not rely on them as such. Due to their unique biodiversity and susceptibility, deep reefs should be included in marine conservation efforts, say the authors.
-end-


American Association for the Advancement of Science

Related Coral Reefs Articles:

A brave new world for coral reefs
It is not too late to save coral reefs, but we must act now.
Regular coral larvae supply from neighboring reefs helps degraded reefs recover
For reefs facing huge challenges, more coral larvae doesn't necessarily translate to increased rates of coral recovery on degraded reefs, a new Queensland study has showed.
Potential for Saudi Arabian coral reefs to shine
Careful marine management and stricter fishing laws could enable Saudi Arabia's coral reefs to thrive.
New coral bleaching database to help predict fate of global reefs
A UBC-led research team has developed a new global coral bleaching database that could help scientists predict future bleaching events.
Fish social lives may be key to saving coral reefs
Fish provide a critical service for coral reefs by eating algae that can kill coral and dominate reefs if left unchecked.
Land-based microbes may be invading and harming coral reefs
A new study suggests that coral reefs -- already under existential threat from global warming -- may be undergoing further damage from invading bacteria and fungi coming from land-based sources, such as outfall from sewage treatment plants and coastal inlets.
Dead zones may threaten coral reefs worldwide
Dead zones affect dozens of coral reefs around the world and threaten hundreds more according to a new study by Smithsonian scientists published in Proceedings of the National Academy of Sciences.
Deep reefs unlikely to save shallow coral reefs
Often highlighted as important ecological refuges, deep sections of coral reefs (30-60 m depth) can offer protection from the full force of climate change-related impacts, such as intensifying storms and warm-water bleaching.
Coral reefs grow faster and healthier when parrotfish are abundant
A new study by Smithsonian scientists and colleagues that reveals 3,000 years of change in reefs in the western Caribbean provides long-term, compelling evidence that parrotfish, which eat algae that can smother corals, are vital to coral-reef growth and health.
Rising CO2 threatens coral and people who use reefs
Damage to coral reefs from ocean acidification and sea surface temperature rise will be worst at just the spots where human dependence on reefs is highest, according to a new analysis appearing in PLOS ONE.

Related Coral Reefs Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#521 The Curious Life of Krill
Krill may be one of the most abundant forms of life on our planet... but it turns out we don't know that much about them. For a create that underpins a massive ocean ecosystem and lives in our oceans in massive numbers, they're surprisingly difficult to study. We sit down and shine some light on these underappreciated crustaceans with Stephen Nicol, Adjunct Professor at the University of Tasmania, Scientific Advisor to the Association of Responsible Krill Harvesting Companies, and author of the book "The Curious Life of Krill: A Conservation Story from the Bottom of the World".