Shopping bags, nets, diapers and toothbrushes are snagging on coral reefs and making them sick, a new study has found. With plastic pollution continuing to rise, there's little relief in sight for the ailing reefs.
Image: picture-alliance/dpa/M. Nelson
Advertisement
Coral reefs that come in contact with plastic waste floating in the ocean are at greater risk of becoming diseased, according to an international study published Thursday.
After examining more than 120,000 corals in 159 reefs in the Asia-Pacific, scientists found 11.1 billion plastic items ensnared in them — including diapers, tea bags, shopping bags, fishnets, bottle caps and toothbrushes.
For corals that come in contact with the plastics, their risk of contracting disease rose from 4 percent to 89 percent.
Plastics don't just hang around populated coastal regions either. Scientists said they were surprised to discover plastic trash in remote reefs as well.
"You could be diving, and you think someone's tapping your shoulder but it's just a bottle knocking against you, or a plastic trash bag stuck on your tank," lead author Joleah Lamb, of Cornell University, told the Reuters news agency. "It's really sad."
What happens when coral gets stressed? Global warming and environmental changes can cause corals to lose their color, and hinder their ability to feed and reproduce. Scientists and policy makers are sounding alarm bells.
Image: imago/OceanPhoto
Trouble in paradise
Some 2,500 scientists, policymakers and managers came together in Honolulu in June 2016 for the world's largest summit dedicated to the future of coral reefs. With coral reefs threatened by global warming, participants at the 13th International Coral Reef Symposium are calling for a joint rescue effort.
Image: picture alliance/WILDLIFE
World is watching
The event gathered guests from 97 countries, including the presidents of Palau, Micronesia, and the Marshall Islands. Coral reefs are a key source of income in those countries, mostly through tourism.
Image: picture alliance/WILDLIFE
Too warm for comfort
The Pacific nations are worried about the future of their tourist hotspots, as coral reefs face so-called "bleaching" due to rising sea temperatures. "If our coral reefs are further degraded, then our reef-dependent communities will suffer and be displaced," leaders of Palau, Micronesia, and the Marshall Islands said in an open letter.
Image: imago/OceanPhoto
Corals in crisis
Bleaching happens when coral is stressed by hot ocean waters or other changes in the environment. In response, corals may release tiny symbiotic algae which drains them of color. More importantly, bleaching affects their ability to feed and reproduce.
Image: Imago
Pale as death
Severe or prolonged bleaching might kill off corals entirely. Scientists have detected bleached coral in the past two years in oceans around the world. They expect the process to continue thought 2016.
Image: imago/blickwinkel
Giant from Down Under
The 2,300-kilometer-long (1,429-mile-long) Great Barrier Reef is the world's largest coral reef system and its largest living structure. It is also among Australia's main tourist attractions, generating around $3.9 billion (3.5 billion euros) annually.
Image: Imago/ZUMA Press
Tough times for the Great Barrier Reef
Almost one-half of the coral in the reef's northern third have died in the past three months [in 2016], according to James Cook University professor Terry Hughes. The most affected area is remote and unpolluted, with very little fishing and no coastal development. "That's an absolute catastrophe," Hughes said. "There's nowhere to hide from climate change."
Image: Dorothea Bender-Champ for ARC Centre of Excellence for Coral Reef Studies
Fighting for hope
Despite the bad news, scientists claim the problems can be managed with proper funding and political backing. "We are not ready to write the obituary for coral reefs," Professor Hughes said. The scientific community at the conference pledged to work with leaders across the world in order to "curb the continued loss of coral reefs."
Image: imago/OceanPhoto
8 images1 | 8
Bacteria-carrying toothbrushes
Although researchers have found a correlation, they're still working on pinpointing precisely how the plastics cause the coral reefs to get sick.
The floating plastic trash could damage the tiny coral animals that build reefs, causing them to become more vulnerable to illness.
"Corals are animals like us and have really thin tissues that can be cut and wounded, especially if they are cut by an item covered in all sorts of micro-organisms," Lamb said.
Furthermore, bits of plastic can also harbor harmful microbes and bacteria in the oceans, which are then deposited on the corals.
Lamb noted that plastics made of polypropylene — such as toothbrushes and bottle caps — can become "heavily inhabited" by bacteria that are associated with a group of coral diseases known as white syndromes.
The study also estimated that the billions of plastic items found in Asia-Pacific coral reefs will likely increase by 40 percent in the next few years, meaning that some 15.8 billion plastic items will be found in reefs by 2025.
Coral reefs provide food, coastal protection and tourism income for some 275 million people worldwide who live near reefs. The ecosystems are already under stress from climate change and overfishing.
What happens when ocean temperatures rise?
With oceans heating up much quicker than expected, the consequences might affect everything from weather to coral reefs.
Image: picture-alliance/dpa/F. Gierth
Atlantis 2.0
As global warming speeds up, so does the rise in sea levels. While 2004 to 2010 saw oceans rise by about 15 millimeters in total, this value doubled for 2010 to 2016. Tropical regions in the western Pacific are especially affected, threatening many of the coastal areas and low-lying islands with submersion by the end of the century.
Image: picture alliance/Photoshot
Breaking the ice
As ocean and atmospheric temperatures increase, glaciers and ice caps shrink in size. In 2016, the global sea ice extent was 4 million square kilometers (1.54 million square miles) below average. Consequently, more meltwater flows into rivers and oceans, which also causes sea levels to rise.
Image: picture-alliance/dpa/U.Mauder
Losing Nemo
Some ocean regions have already warmed by more than 3 degrees Celsius, upsetting marine ecosystems. Seventy-two percent of demersal fish species in the northeast Atlantic Ocean have so far been affected, with warming limiting their abundance and spread. Species that live in tropical ocean waters, like the clownfish, are also experiencing habitat-related population decreases.
Image: imago/OceanPhoto
Coral bleaching
Warming and acidifying waters affect Nemo's navigation senses, and also threaten his home - coral reefs, one of the most sensitive marine ecosystems. A water temperature increase of as much as 3 degrees Celsius can cause the death of corals and the marine animal species that live in them. Northern parts of Great Barrier Reef have seen coral mortality rates of 50 percent.
Image: imago/blickwinkel
Stormy weather
With increased ocean heat, extremely strong tropical storms are set to occur much more frequently. One of these massive storms was Hurricane Matthew, which hit Haiti in October 2016. The Haitian government put the official death toll at 546, and the hurricane also caused $15 billion (13.8 billion euros) in economic losses on the island nation and in the US, Cuba and the Bahamas.
Image: Reuters/NASA/Alexander Gerst
Heads or tails
There is a strong correlation between atmospheric wind patterns and ocean temperatures, meaning warming waters may also cause the jet stream to get stronger. This could affect airplane travel due to intensified head- and tailwinds. On the upside, this means that some flights may be much faster. On the downside, other flights may take longer and could experience more turbulence.
