Ocean 'dead zones' cover an area larger than the UK
Jennifer Collins
August 3, 2017
The meat industry is being blamed for the worst ever dead zone in the Gulf of Mexico. Why do these oxygen-poor stretches of ocean, which can't support most marine life, continue to expand? Global Ideas takes a look.
Image: picture-alliance/AP Photo
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Dead zones - areas of water so starved of oxygen that most marine life cannot survive there - are spreading. At the last count, there were 405 such zones worldwide, covering 245,000 square kilometers (94,600 square miles) - or an area slightly larger than the United Kingdom.
In summer 2017, a dead zone in the Gulf of Mexico is set to approach more than 20,700 square kilometers - the largest expanse ever recorded there. The Baltic Sea dead zone has grown to 60,000 square kilometers in recent years.
Such low oxygen areas can occur naturally but scientists believe human activities trigger or worsen them. Excess runoff from farms and sewage systems rich in nitrogen and phosphorus can stimulate huge algal blooms. When the algae die, they decompose, sucking up oxygen as they sink to the bottom.
Dead zones are bad news for fishermen Image: Hector Guerrero/AFP/Getty Images
In the case of the Gulf of Mexico dead zone, manure and fertilizer used in the production of huge amounts of corn and soy for animal feed are largely to blame, according to a report by environmental group Mighty Earth. The group named Tyson Foods, America's largest meat company, as one of the biggest culprits.
Increasing water temperatures due to climate change are exacerbating the problem too, say scientists.
This, of course, is all bad news for the fishing industry and it can also affect beachgoers, with some seafronts being closed down due to the pollution and stench.
Expansion of dead zones in our already overburdened oceans isn't inevitable. Scientists say the Gulf of Mexico's annual dead zone could be reduced significantly with a 59-percent drop in the amount of runoff flowing into the Mississippi River, for instance. But this will require swift action from lawmakers and industry.
Marine protected areas in pictures
Conserving our seas is a must. As awareness of the problems facing ocean wildlife and habitat grows, so too do the number of marine protected areas. Albeit slowly. Click or swipe through our gallery to learn more.
Image: imago/blickwinkel
Pacific Remote Islands Marine National Monument
Covering an area of almost 1.3 million square kilometers (800,000 square miles), this is among the world's largest marine protected areas. Located in the western Pacific Ocean, it is home to all manner of marine life including green turtles, pearl oysters, giant clams, reef sharks, coconut crabs, dolphins and whales.
Image: imago/blickwinkel
Pitcairn Islands Marine Reserve
Surrounding this British Overseas Territory lies the largest contiguous marine protected area in the world. The 834,334 square kilometers of pristine ocean habitat are monitored via satellite to track potential illegal fishing activity in this vast and remote corner of the South Pacific.
Image: picture-alliance/dpa
The Great Barrier Reef Marine Park
Situated off the northeastern coast of Australia, the Great Barrier Reef is the largest in the world. A vast area of that reef, which is so big it can be seen from space, forms the Great Barrier Reef Marine Park. The reef saw devastating coral bleaching in 2016 and 2017. In an effort to protect the delicate ecosystem, fishing is strictly regulated and commercial ships can only use certain routes.
Image: imago/blickwinkel
Galapagos Marine Reserve
A UNESCO World Heritage Site and home to many animals found nowhere else in the world, the Galapagos Marine Reserve in the Pacific Ocean is administered by Ecuador and is the largest marine park in a developing country.
Image: imago/Westend61
Bowie Seamount marine protected area
The Bowie Seamount is an underwater volcano located 180 kilometers off the west coast of Canada. Although the volcano rises about 3,000 meters from the ocean bed, its highest point is 24 meters below sea level. While it may be invisible to those of us living above water, the submerged mountain is home to a rich mix of marine fauna and flora.
Image: BR
Chagos archipelago
The United Kingdom declared this vast stretch of Indian Ocean a marine protected area in 2010. The legality of the move has been contested by Mauritius, which lays claim to the group of islands. In the 1970s, the UK evicted the entire native population from the archipelago and granted the United States permission to use it as a military base.
Image: NASA Johnson Space Center/Image Science & Analysis Laboratory
The Schleswig-Holstein Wadden Sea National Park
Extending from the German-Danish maritime border down to the Elbe estuary, and with an area of 4,410 square kilometers, this is doubtless Germany’s largest national park. Due to the intertidal nature of the Wadden Sea, some 30 percent of it is only periodically under water.
Image: picture-alliance/dpa
The Pelagos Sanctuary for Mediterranean Marine Mammals
Covering a large area between the French Riviera, Sardinia and the Italian region of Tuscany, this sanctuary was established specifically to protect marine mammals. It is currently the world's only conservation area in international waters.
Image: picture-alliance/Wildlife
Ross Sea Region Marine Protected Area
In October 2016, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) agreed to create a marine protected area off the coast of Antarctica. However, the 1.6 million square kilometers of pristine wilderness will only be protected for 35 years. What happens after remains to be seen.
Image: REUTERS/P. Askin
Aquatic Reserve of the South of Gabon
The government of Gabon announced in June 2017 creation of a 53,000-square-kilometer network of marine protected areas - the largest in Africa. It would apply to a quarter of Gabon's seas, which are incredibly rich in life, including sea turtles, whales, dolphins, corals, even crocodiles. The region is known for rampant overfishing - the reserves are accompanied by a sustainable fishing plan.
Image: Imago/Nature Picture Library
Cook Islands Marine Park
In July 2017, the Cook Islands - a small island nation about halfway between New Zealand and Hawaii - approved designation of the world's new largest marine sanctuaries off its shores. The 1.9-million-square-kilometer preserve includes a core no-fishing zone, otherwise limits on mineral extraction and commercial fishing. It's hoped to help preserve the archipelago's lagoons and reefs.
