Scientists around the world are looking for all kinds of ways to protect and maybe even revive corals. One option is to create more marine protected areas —essentially national parks in the ocean. Scientists say creating marine refuges, where fishing, mining, and recreating are off limits, make the reefs healthier, and so more resilient. An estimated 4, fish species, and some 25 percent of marine life, depend on coral reefs at some point in their existence.
Fish keep the algae that grow on corals in check, allowing corals to breathe and access sunlight. At a talk hosted by the Woods Hole Oceanographic Institution on Wednesday, renowned marine biologist Sylvia Earle promoted the idea of using marine parks to protect coral, which she does through her organization Mission Blue.
A recently published assessment of 1, reefs in 41 countries found that only 5 percent of reefs were able to provide all of their lucrative byproducts, such as healthy fish stocks and biodiversity. To increase that percentage, new marine reserves will need to be strategically placed in areas well away from humans, say experts. Beyond such nature preserves, some conservationists are looking to more hands-on methods.
One research center in the Florida Keys is exploring a form of natural selection to keep corals afloat. To keep the wild ecosystem alive, Muller and her team are harvesting samples of the corals that have survived the environmental stresses naturally, breeding them by hand, and reattaching them to the reef. At any given time, the center has 46, corals growing on underwater plastic lattices in its nursery. So far, the center has regrown over 70, corals from five different species on damaged reefs.
In Massachusetts, Cohen's research has found two key elements that seem to protect corals. On average, these lagoons submerge coral in water that is two degrees Celsius warmer than the water outside the lagoons.
Coral reefs are essential to healthy coasts and vibrant economies, playing a critical role in everything from protecting lives and property to supporting thousands of businesses. The total economic value of coral reef services for the U. Worldwide, more than million people depend on coral reefs for food, income, coastal protection, and more.
New management actions are desperately needed to ensure reefs continue to exist and recover their structure and function where that has been compromised. Fortunately, scientists, conservationists, and environmental managers across the globe are developing and implementing new strategies to protect and conserve these ecosystems against a suite of local and global threats. In addition to understanding and communicating the importance of coral reefs , it is also critically important to understand the status of coral reefs around the world and the extent to which they are at risk.
Grey areas represent periods for which no observed data were available. Below are key findings from the Reefs at Risk Revisited report ref that quantified the current threats to coral reefs worldwide and projected the risk of future degradation. This map shows a global classification of coral reefs by the estimated present threat from local human activities, according to Reefs at Risk integrated local threat index.
Inspired by similar research in trees, which revealed new insights into the extinction risk of Amazonian tree species and led to more ambitious global reforestation targets , we decided to estimate how many corals there were in the Pacific Ocean. The project was daunting at first, to say the least. Primarily because ecological data are notoriously scarce in corals at large spatial scales. For instance, the availability of remote sensing data, which has been instrumental to comparable estimates in trees and other organisms, is still limited in coral reef ecosystems, though rapidly expanding.
Furthermore, coral abundances are typically measured as percentage cover of benthic habitat, rather than counts of individual coral colonies, and are rarely recorded at the species level. We faced the following four challenges. First, to map the extent of coral habitat across the Pacific Ocean. Second, to split coral habitat into the three most common reef habitat types: the reef crest, slope and flat, across which the abundances of corals and individual species are known to vary widely.
Third, to estimate how the density of coral colonies varies between these habitats and across the Pacific Ocean. And four, to estimate the relative abundances of more than coral species in the three habitats and in different parts of the Pacific. To overcome these challenges, we combined spatial data on the global distribution of coral reefs, detailed maps of coral reef habitat, species abundance data collected across the Pacific, and a new approach to modelling species abundances.
The nature of the available data made three things abundantly clear. First, a project like this would not be possible without the generosity of fellow scientists sharing their data. Second, although estimates at such scales are inevitably uncertain, they can reveal valuable and robust insights into the functioning and conservation of our biosphere. And third, science is a work in progress: as more detailed data become available in the future, our estimates will improve.
So how many corals are there in the Pacific Ocean? According to our best estimates, half a trillion! There are thus approximately as many coral colonies in the Pacific Ocean as there are trees in the Amazon, and more corals than birds in the world. The population sizes of one fifth of the species we examined each exceed one billion individuals.
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