In the guide below, we discuss a range of issues and solutions relating to coral reefs.
We discuss why they are important, how much coral has been lost, whether coral might disappear in the future, the main problems and threats coral might face, and potential solutions to save or restore coral reefs.
First, Why Are Coral Reefs Important?
A few of the main reason coral reefs might be important, particularly to marine environments and society, might include that they:
– Significant Source of Biodiversity Marine Environments
According to several reports, coral reefs support more biodiversity and species per unit area than any other marine environment
We’ve outlined why biodiversity might be important in this guide
– Provide A Habitat For Marine Life
Provide a habitat for a range of marine life, as well protection and shelter for smaller marine life
This habitat may also contribute to the growth or stability of some marine life populations
… coral reefs support about 25% of marine life (brightly.eco)
An estimated 4,000 fish species, and some 25 percent of marine life, depend on coral reefs at some point in their existence (nationalgeographic.com)
– Contribute To Marine Ecosystems As A Whole
With the other functions coral reefs can provide, they can contribute to the marine ecosystem as a whole
– Reduce Erosion On Coastlines & Beaches
By dissipating wave energy before it gets to shore, and also trapping sand and sediments on coastlines
– Are A Source Of Seafood
Commercial fishing and recreational fishing like spearfishing can be conducted in and around reefs to obtain seafood.
– Are A Source Of Medicine
Some extracts of sponges, and other chemical compounds found on reefs can be used in modern medicine and new drugs for a range of health conditions
– Are A Source Of Commodities & Materials
Coral can be mined as a source of limestone, and other construction materials can come from coral too
– Contribute To Employment & Income
Fishermen, tourism service providers, recreational diving and snorkelling providers, and others make their living around and receive an income in part due to coral reefs
An estimated 500 million people earn their livelihoods from the fishing stocks and tourism opportunities reefs provide (nationalgeographic.com)
– Provide Recreation
Such as tourism, and diving and snorkelling opportunities.
Are Coral Reefs Dying Or In Danger?
Coral can be dying or in danger if:
– Coral is in poor health
– Or, it’s at risk from certain problems and threats that negatively impact coral
Various estimates indicate that close to half, or slightly more than half of all coral might be dying or at risk in some way
Only 46% of the world’s reefs could be currently regarded as in good health and about 60% of the world’s reefs may be at risk due to destructive, human-related activities.
How Much Coral Has Died, & How Much Have We Lost?
It appears as though half of the coral on Earth has died or disappeared, and it’s happened relatively quickly and recently over a short time span.
We’ve lost 50% of coral reefs to date … And that’s only happened in 30 to 35 years, so we’re looking at very small timelines, and massive problems in those small timelines.
Other reports indicate that large %’s of coral have died in specific regions where mass bleaching events have taken place over short multi year periods. One example of this was in 2016 and 2017 on the Great Barrier Reef.
How Much Coral Is Left In The World?
Based on the above estimate, there might be 50% of coral remaining in the world.
Will Coral Reefs Go Extinct Or Disappear In The Future? If So, When?
Various estimates indicate that most of the remaining coral might disappear in the next 20 to 30 years if current trends keep up.
By the year 2100, one report indicates almost all coral might be eliminated.
Over the next 20 years, scientists estimate about 70 to 90% of all coral reefs will disappear primarily as a result of warming ocean waters, ocean acidity, and pollution
By 2100 there will be nearly zero suitable coral habitats remaining, eliminating nearly all living coral reef habitats.
It’s predicted that in another 30 years [from now] most coral reef ecosystems can be at the point of collapse and functionally, not being able to reproduce fast enough to keep up with the effects of ocean temperatures rising
By the 2030s, 90% of reefs are expected to be at risk from both human activities and climate change; by 2050, it is predicted that all coral reefs will be in danger
From secore.org: ‘… up to 90 percent [of coral’ may die within the next century’
Can Coral Recover?
Some reports indicate that ocean conditions could be too stressful in the future for coral and reefs to survive
When taking into consideration ocean warming and coral bleaching specifically as one example, nytimes.com indicates that some coral can sometimes recover over the course of a decade or more when the water cools again, but sometimes the effects are irreversible or there is a mass die off
So, there might be some debate about whether coral will survive into the future, or how much will survive.
Whether coral can recover or be restored again, might depend on factors such as:
– The species of coral (for example, the IUCN lists threatened species, and lists some reef-building coral species as more threatened than others)
– The specific ocean region or zone in question (as one example of this, wikipedia.org indicates that coral might be at risk in some regions more than others as ‘The threat to the health of reefs is particularly strong in Southeast Asia, where 80% of reefs are endangered.’. They also indicate that the coral triangle region might have more reef-building coral species in the threatened species category with the IUCN)
– Whether problems and threats to coral get worse, or better
– How effective potential solutions to preserve, restore or grow coral are
– Something nationalgeographic.com also notes, is that some species of coral might be showing signs of naturally evolving or adapting to deal with warmer temperatures. So, this is a variable that may impact future coral population numbers too
What Are The Some Of The Main Problems & Threats For Coral Reefs?
Main Problems & Threats
The main problems and threats for coral reefs are reported by various reports as being:
– Warming Surface Temperature Of Oceans
Warming oceans are caused by a warming atmosphere and climate, whereby the ocean absorbs this heat.
The increase in ocean temperatures stresses coral, and leads to a series of events that results in ‘Coral Bleaching’.
Coral bleaching ends in corals turning white, and can cause coral to die off.
– Increased Carbon Absorption By Oceans, Leading To More Acidic Ocean Water Chemistry
More carbon in the atmosphere means that the ocean absorbs more carbon.
When the ocean absorbs too much carbon, it can lead to ocean acidification.
Ocean acidification is when the chemistry of the ocean water changes and becomes too acidic.
When waters are too acidic, coral can grow slower, and also become more vulnerable or weaker, because it can be harder for them to grow their skeletal structure.
– Pollution In The Ocean
Pollution in the ocean might not only lower the water quality for coral (via pollutants, contaminants, sediments, nutrients, and toxic substances and chemicals), but is can also impact coral in other ways such as increasing the possibility of disease when bacteria, pathogens and other disease causing organisms get into the ocean.
Pollution may run off, or leach into the ocean from a range of land based sources (we list some of those sources and types of waste pollutants here)
A commonly reported source is farms and agricultural operations, where synthetic fertilizers can wash off and run off from agricultural fields into water sources (like rivers), or into the soil, and eventually run off into the ocean.
Other sources might include but aren’t limited to industrial processing and manufacturing facilities, stormwater and waste water runoff, and even direct dumping into the ocean.
Some reports even indicate that microplastics are a main source of pollution, as plastic can carry organic pollutants from land into the ocean, and coral also consume microplastics (which contain petroleum, and can contribute to coral disease)
The ocean also has the ability to absorb air pollutants
Sunscreen also has the ability to enter the ocean through wastewater outlets, and some sunscreen contain chemicals that threaten coral health
Oil spills may also pollute the ocean and impact coral
Other Potential Problems & Threats
– Physical Damage
From development close to reefs, and activities in the ocean, like dredging, destructive or damaging fishing practices (where fishing gear damages coral and reefs), and so on
– Coral Mining
Coral is mined in particular for limestone, and this obviously depletes coral.
Coral mining has been banned in some waters, whilst in others it still happens
– Coral Harvesting
Coral can be removed from the ocean for use in other goods
When marine life is overfished near coral, this can have a cascade effect whereby marine life aren’t able to perform functions that contribute to coral health
Between coral and seaweed for example
Some fish, such as crown-of-thorms starfish, eat living coral
If these predator populations grow, coral can be at threat
Local Problems For Coral vs Global Problems
Each region in the world might have different local issues impacting coral, in addition to global problems.
wikipedia.org lists some coral problems and threats by region.
How To Save Coral Reefs – Potential Solutions To Conserve Them
Potential Main Solutions
– Reducing Carbon Emissions
Reducing carbon emissions from human sources may have a two fold effect.
Not only might it help slow a warming climate and heat absorption by oceans, but it might also help reduce the amount of carbon oceans are absorbing.
Consequently, coral bleaching and and ocean acidification might become less significant threats to coral.
– Reducing Ocean Pollution
There’s a range of potential solutions for reducing ocean pollution.
But, they might all be based around less pollutants getting from their source into the ocean.
Solutions could range from changing the use of certain synthetic agricultural fertilzers and chemicals in agriculture, to better treatment of waste at manufacturing and waste water facilities, to reducing direct dumping of waste into the ocean.
Reducing plastic litter, and reducing plastic waste could also help.
Reducing air pollution may also help
Other Potential Solutions
– Reducing Or Banning Coral Mining
Less coral mining means less coral being damaged or depleted
– Consider The Benefit Of Artificial Reefs
Artificial reefs may be one way to provide new surfaces for coral to attach to and grow on.
Although, artificial reefs have their own pros and cons to consider too.
– More Sustainable Fishing Practices
Which might help better preserve marine life populations in and around coral reefs by reducing overfishing, in addition to reducing destructive and damaging fishing practices (such as bottom trawling)
– Regulations & Treaties That Protect Coral Reefs
These regulations and treaties might restrict or ban practices that damage, deplete or contribute to the poor health of coral
Marine protected areas that limit or ban certain activities might also be an option
Other Coral Preservation, Coral Restoration, & Coral Growth Technologies & Methods
These technologies and methods might include but aren’t limited to:
– Coral Propagation
What essentially amounts to coral farming
Coral can either be broke into fragments (via fragmentation), or spawn naturally
‘Counting Coral’ is an example of a non-for-profit organisation that has developed a coral propagation technique to help with healthy coral growth
– Coral Transplantation
Involves physically relocating coral fragments from one location to another, such as from a natural reef to an artificial reef
– Lab Grown Coral
Involves breeding or reproducing different species or types of coral in a lab.
Developments in this field are still ongoing.
news.mongabay.com discusses this in more detail, and so does nationalgeographic.com
– Gene Edited Coral
Testing on gene edited coral is showing some positive signs of being able to withstand certain environmental stresses, such as higher water temperatures.
phys.org discusses this in more detail, and nationalgeographic.com does too