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Corals Saving Corals | Earth Wise

December 29, 2022 By EarthWise Leave a Comment

A new study by researchers at the University of California, Davis, has found that under the right circumstances, disease-resistant corals can rescue corals that are more vulnerable to disease.

The researchers monitored a disease outbreak at a coral nursery in the Cayman Islands. They tracked the presence of disease in 650 coral fragments in various arrangements over a period of five months. They found that some corals are more resistant to disease just by being around other corals that are particularly resistant. In general, when there are only corals of the same genetic makeup, they are more vulnerable to disease than corals that grow among a mixture of genotypes. But beyond that, some vulnerable corals become more resistant to disease just by being around other corals that are particularly resistant. Proximity to the resistant genotypes helped to protect the susceptible corals from the effects of disease.

These findings provide new evidence that genetic diversity can help reduce disease transmission among corals and furthermore, it is important to consider how corals are arranged in coral nurseries or in reef restoration projects.

The ability of resistant coral to help protect vulnerable individuals appears to be similar to how vaccinations work among humans. Vaccinated individuals resist a disease, which effectively erects a barrier that weakens a disease’s ability to move through a population.

The researchers hope that the findings of this study will be integrated into coral nursery and reef restoration projects. By intentionally arranging corals with mixtures of genotypes, it will help rebuild coral resilience and help those corals that are vulnerable to disease to thrive.

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Corals Saving Corals

Photo, posted December 30, 2014, courtesy of NOAA’s National Ocean Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Turning Food Waste Back Into Food | Earth Wise

March 3, 2021 By EarthWise Leave a Comment

Scientists at the University of California Riverside have discovered that fermented food waste can boost bacteria that increase crop growth, make plants more resistant to pathogens, and reduce the carbon emissions resulting from farming.

Food waste is a serious problem from multiple perspectives. As much as 50% of food is thrown away in the United States and most of that simply ends up in landfills, taking up more than 20% of America’s landfill volume. Food waste is a huge economic loss as well as a significant waste of freshwater resources used to produce food.

The researchers studied byproducts from two kinds of food waste readily available in Southern California: beer mash – a byproduct of beer production – and mixed food waste discarded by grocery stores.

Both types of waste were fermented and then added to the irrigation system watering citrus plants in a greenhouse. Within 24 hours, the average population of beneficial bacteria was two to three orders of magnitude greater than in plants that did not receive the treatments. This led to improvements in the carbon to nitrogen ratio in crops. When there are enough so-called good bacteria in plants, they produce antimicrobial compounds and metabolites that help plants grow better and faster.

The results of the study suggest that the use of food waste products in agriculture is beneficial and could complement the use of synthetic chemical additives by farmers, perhaps eliminating it entirely. Crops would in turn become less expensive.

Making use of food waste in agriculture is a step towards a more circular economy in which we use something and then find a new purpose for it.

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Turning food waste back into food

Photo, posted October 28, 2012, courtesy of Daniel Lobo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Heat-Resistant Coral | Earth Wise

June 23, 2020 By EarthWise Leave a Comment

Coral reefs are in decline all over the world. Corals are under increasing pressure as water temperatures rise and the frequency and severity of coral bleaching events increase. Nowhere is this more evident than in Australia’s Great Barrier Reef system, where severe bleaching events have happened in three of the past five years. Long-term prospects for the survival of the world’s largest reef system are now considered to be poor.

A team of scientists at Australia’s national science agency – the Commonwealth Scientific and Industrial Research Organization – along with the Australian Institute of Marine Science and the University of Melbourne have successfully produced in a laboratory setting a coral that is more resistant to increased seawater temperatures.

The team made the coral more tolerant to temperature-induced bleaching by bolstering the heat tolerance of the microalgae symbionts that live inside the coral tissue. They isolated the microalgae from coral and cultured it in the laboratory using a technique called “directed evolution”. Over the course of four years, they exposed the microalgae to increasingly warmer temperatures. When the heat-adapted strain of algae was reintroduced into coral larvae, the newly established coral-algal symbiosis was more heat tolerant than the original one. The heat-tolerant microalgae are better at photosynthesis and improve the heat response of the coral animal.

The next step is to further test the algal strains in adult colonies across a range of coral species. This groundbreaking research provides a promising and novel tool to increase the heat tolerance of corals and might potentially lead to a way to save the Great Barrier Reef as the world continues to warm.

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Scientists successfully develop heat resistant coral to fight bleaching

Photo, posted September 22, 2010, courtesy of NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Is There Hope For Coral Reefs?

January 16, 2019 By EarthWise Leave a Comment

News about the world’s coral reefs has been relentlessly bad for a number of years. Warming, acidifying oceans have wreaked havoc with coral reefs leading to enormous losses. Nowhere have things been more dire than in Australia’s Great Barrier Reef. Coral bleaching events have been increasingly common and severe over the past two decades. In fact, only 7% of the Great Barrier Reef has escaped bleaching entirely since 1998.

While the future of the world’s coral reefs is very much uncertain as global heating continues, there is a recent bit of hopeful news. According to a study published in Nature Climate Change, the response of the Great Barrier Reef to the extreme temperatures in 2017 was quite different from that of the previous year in the aftermath of back-to-back bouts of coral bleaching.

Surprisingly, corals that bleached in 2016 but managed to survive were more resistant to the recurrence of hot conditions in 2017.

Many corals don’t survive bleaching events at all and, of course,those corals don’t bleach for a second time. But the surviving corals from the 2016 bleaching event were tougher species. As a result of bleaching, the mix of coral species on the reef is changing very rapidly. The net result was that there was less bleaching in 2017 even though the temperatures that year were even more extreme than in 2016.

There have now been four mass bleaching events on the Great Barrier Reef over the past 20 years and it is only a matter of time before another one occurs triggered by the next marine heatwave. Almost half of the corals on the northern two-thirds of the reef have been killed. But at least some of the reef is showing impressive survival skills.

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A glimmer of hope for the world’s coral reefs

Photo, posted November 29, 2012, courtesy of Robert Linsdell 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.

Using Rye To Grow Edamame

April 17, 2018 By EarthWise Leave a Comment

Herbicide-resistant weeds are becoming a more and more common problem for farmers growing grain and vegetable crops. As a result, the farmers are looking for alternatives to herbicides to control weeds. One promising approach is the use of cover crops, which are planted in the off season to protect the soil. Thick cover crop growth can often compete well with weeds during the cover crop growth period, and can prevent most germinated weed seeds from completing their life cycle and reproducing.