coral bleaching

Pesticides In The Great Barrier Reef

November 7, 2019 By EarthWise Leave a Comment

Australia’s Great Barrier Reef is one of the greatest natural wonders in the world and it has been under siege by warming waters and ocean acidification. Widespread coral bleaching has damaged or destroyed large portions of the 1,400-mile long coral reef system. But the effects of climate change are not the only threat to the reef. Pesticides found in waterways that flow into the Great Barrier Reef are another serious problem.

According to a new study by the University of Queensland, the combined toxicity of 22 of the most common pesticides that flow into the Reef are not meeting pollution reduction targets.

Different pesticides affect different organisms. Herbicides affect organisms that photosynthesize such as seagrass, corals, mangroves, and algae. Insecticides affect insect larvae in freshwater, and crustaceans such as crabs, prawns, and lobsters. Previous assessments have only examined individual pesticides and only for limited times. The new study has utilized a methodology that estimates the combined toxicity of multiple pesticides found in the waterways that discharge into the Reef and does it for the entire wet season.

The research revealed that the pesticide reduction target set in the Australian Government’s Reef 2050 Water Quality Improvement Plan is not being met. Only one natural resource management region – the Cape York region – was found to be meeting its target.

By having estimates of the risk posed by pesticides in the various regions and individual waterways, governments, farmers, and conservationists can see which areas pose the greatest risk and where to maximize efforts. Stakeholders have to come together to reduce pesticide concentrations through better management practices and by using less toxic pesticides.

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High pesticide concentrations continue to enter Great Barrier Reef

Photo, posted July 29, 2010, courtesy of Kyle Taylor via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saved By The Trees

February 1, 2019 By EarthWise Leave a Comment

The island of Kokota, part of the Zanzibar Archipelago off the coast of Tanzania, is tiny – only one square kilometer and home to just 500 people. For centuries, its residents subsisted by harvesting the islet’s natural resources, including its trees.

By the early 21st century, the deforestation had become unsustainable and the islanders faced a crisis. Fisheries were depleted, and rivers ran dry. The changing climate brought rising sea levels, more erratic rainfall, and coral bleaching in the surrounding waters. The situation looked hopeless.

But in recent years, the island has come back from the brink of ruin. Reforestation efforts began in 2008 on the larger island of Pemba and on Kokota itself, led by a Pemba local and a Canadian tree planter who formed the non-profit Community Forests International. Since then, nearly 2 million trees have been planted on the two islands. Enthusiastic volunteers on Kokota usually help plant trees during the rainy season, when water is plentiful.

Community Forests International, along with spearheading the tree planting effort, also built Kokota’s first school, and installed rainwater storage tanks for the community.

The conservation group is now devising ways for Kokota to make more money by diversifying its agriculture with crops that grow well in its climate including spices like cloves, cinnamon, and nutmeg. They are also helping locals to grow more and different vegetables in their gardens.

Small, poor communities are often the most vulnerable to the effects of climate change, such as drought, powerful storms, and depleted fisheries. Tiny Kokota provides an example of an environmental comeback. Fighting climate change requires economic solutions along with environmental solutions. For this one tiny island, it appears to have been saved by the trees.

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This island was on the brink of disaster. Then, they planted thousands of trees.

Photo, posted July 18, 2015, courtesy of Marco Zanferrari via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Heat-Resistant Corals

August 31, 2018 By EarthWise Leave a Comment

All over the world, coral reefs are being wiped out by rising sea temperatures brought about by climate change. When sea temperatures get too high, the symbiotic relationship between coral polyps and microscopic algae living within the coral breaks down and the coral either digests or expels the algae. The result is coral bleaching which weakens, and if it persists, kills the coral.

A Small Win For Coral

August 15, 2018 By EarthWise Leave a Comment

The Belize Barrier Reef is the largest barrier reef system in the Northern Hemisphere. It extends roughly 200 miles, and is made up of a series of coral reefs, cays and islands, many of which are covered with mangroves. It was designated a Unesco World Heritage Site in 1996, and added to its endangered list in 2009.

A Philippine Coral Reef Survives

January 2, 2018 By EarthWise Leave a Comment

One of the greatest coral reef ecosystems in the world, the Tubbataha Reef in the Philippines, continues to prosper. Undersea coral walls that plunge more than 300 feet deep are home to some 600 species of fish and 360 kinds of coral, about half of all known species. According to experts, the ocean wilderness of Tubbataha Reef is about the closest thing to a true natural state for any reef in the world.

Could Coral Reefs Be Wiped Out?

August 8, 2017 By EarthWise

A new study warns that coral reefs are in danger of disappearing forever. According to U.N. research, the world’s coral reefs could die out completely by mid-century unless carbon emissions are reduced enough to slow ocean warming.

The Great Barrier Reef

April 27, 2017 By EarthWise

According to a new paper published in the journal Nature, global warming has damaged huge sections of Australia’s Great Barrier Reef. The authors of the paper warn that the resilience of the reef – which is the world’s largest living structure – is waning rapidly.

Some Good News For Coral Reefs

August 12, 2016 By WAMC WEB

Most recent news about coral reefs around the world has been bad news. There has been unprecedented coral bleaching in places like Australia’s Great Barrier Reef. The effects of climate change – including warming temperatures and rising seas – as well as the recent El Niño event have led to damaged reefs across the globe.

Coral Bleaching On The Great Barrier Reef

May 9, 2016 By WAMC WEB

It was already well-known that coral bleaching was a serious problem in the Great Barrier Reef, but extensive aerial surveys and underwater dives have now revealed the shocking extent of the problem.