Biodiversity Helps Coral Reefs Thrive and Could Be Used Strategically to Save Them
By Cody Clements
Coral reefs are home to so many species that they often are called "the rainforests of the seas." Today they face a daunting range of threats, including ocean warming and acidification, overfishing and pollution. Worldwide, more than one-third of all coral species are at risk of extinction.
I am one of many scientists who are studying corals to find ways of helping them survive and recover. As a recent report from the National Academies of Science, Engineering and Medicine shows, researchers are exploring many different strategies. Some, such as managed breeding to make corals more tolerant of stresses, are already being developed at small scales. Others, such as moving corals to colonize new areas, have not been tested yet.
My own work examines whether greater diversity of coral species on reefs can help corals survive and thrive. In a study published earlier this year, my colleague Mark Hay and I found evidence that the answer is yes. This finding could help to inform broader strategies for making coral reefs more resilient in altered oceans.
In Nature, More Is Better
Are ecosystems healthier if they contain many species than if they harbor only a few? This is a central question in ecology. Generally, scientists have found that ecosystems with more diverse foundation species – those that define a system and are inseparable from it, such as trees in a forest – tend to be healthier and function better.
Until recently, no one had applied this test to coral reefs. But we do know that healthy coral reefs are diverse, structurally complex ecosystems dominated by corals. In contrast, reefs that have been damaged by stresses such as coral bleaching events tend to become simplified, less diverse landscapes, often dominated by seaweeds.
For our study we chose a reef area on the southwestern coast of Fiji's main island, Viti Levu, in the South Pacific. Many reefs along this coast have been heavily degraded by overfishing and other human-related activities, reducing coral cover and allowing seaweeds to dominate.
There are hundreds of coral species across the Pacific, but at smaller scales, we found just five species or fewer during preliminary surveys conducted on the degraded reef at our site. Since these conditions mirror what is happening to many reefs worldwide, we saw it as an ideal place to test whether coral diversity matters for the "new normal" that we expect to see on reefs of the future.
Our team created 48 concrete plots on the sea floor of the degraded reef, which served as the bases for experimental coral gardens. We created single-species gardens that each contained one of three coral species – Pocillopora damicornis, commonly known as cauliflower coral; Porites cylindrica, also known as yellow finger coral; and Acropora millepora, one of a number species known as staghorn corals. We also planted mixed gardens containing all three species.
We chose these corals because they are common to reefs across the Pacific and are representative of different coral families that have shown varying responses to a variety of harmful disturbances. In all, each garden contained 18 coral individuals, for a total of 864 corals.
To assess each coral's performance as it grew, we needed to remove them from their plots periodically. So we cut off the tops of hundreds of soda bottles and planted an individual coral in the upside-down neck of each bottle with epoxy putty. We embedded the bottle caps into our concrete slabs so that we could easily unscrew each bottle neck to examine the coral it held, then screw it back into its base. Over 16 months we weighed the corals and tracked other measures of their well-being, including tissue death and colonization of each garden by harmful seaweeds.
Experimental coral gardens on a degraded reef in Fiji. Gardens with a mix of coral species performed better than gardens containing only one species.
Cody Clements / CC BY-ND
We consistently found that corals grown in mixed-species gardens performed better than those in single-species plots. Within four months, coral growth in the mixed-species gardens was even exceeding the best-performing single-species gardens. This suggests that different species may benefit each other in yet unknown ways, at least during early stages of a coral community's development.
Examples of single- and mixed-species coral gardens through time during our 16-month experiment. At four months, mixed-species gardens were outperforming single-species gardens in multiple ways – growing faster on average than even the best performing single-species gardens (Acropora millepora). By 16 months, growth was comparable between mixed-species and Acropora gardens, but aggregate performance of single-species gardens continued to lag behind their mix-species counterparts.
Clements and Hay, 2019 / CC BY-ND
Why Is More Better?
The next question is what drove the effects that we observed. We hope to investigate a number of leads in future experiments. For example, farmers commonly observe that planting a diverse mix of crops helps to reduce the spread of infectious diseases among individuals. Could the same be true for coral reefs?
Our initial findings offer both concern and hope for the future of coral reefs. If diversity is integral to coral well-being, then continued species loss could dramatically alter these ecosystems in ways that lead to further reef decline. How many parts can be removed from the "ecosystem engine" before it breaks down?
That said, many of the strategies in the National Academies report involve using biodiversity – both at the genetic and species level – to enhance coral reef resilience. Examples include cross-breeding corals between populations; altering coral genes to give them new functions, such as higher heat tolerance; and moving stress-tolerant corals or coral genes to new locations.
Promising advances in technology, such as mapping coral reefs from the air, may also help researchers assess coral health and determine which species they contain. This baseline information may help better inform management and restoration efforts.
Corals are in trouble, but they aren't down for the count yet. Perhaps harnessing the power of their remaining biodiversity can help give them a fighting chance.
Researchers Use Technology and Nature to Save Hawaii’s Coral Reefs From Invasive Algae https://t.co/FIeqApvnCC— PFMC (@PacificCouncil) August 17, 2018
Cody Clements is a postdoctoral fellow at the Georgia Institute of Technology.
Disclosure statement: Cody Clements receives funding from the National Science Foundation, the National Institutes of Health, the National Geographic Society, and the Teasley Endowment to the Georgia Institute of Technology.
Reposted with permission from our media associate The Conversation.
EcoWatch Daily Newsletter
If weather is your mood, climate is your personality. That's an analogy some scientists use to help explain the difference between two words people often get mixed up.
Size Matters<p>Climates are a bit like woven tapestries. The big picture is important, no question. But so are all the seemingly minor details found inside the larger whole.</p><p><a href="https://research-information.bris.ac.uk/en/persons/tommaso-jucker" target="_blank">Tommaso Jucker</a> is an environmental scientist at the University of Bristol. In an email, Jucker says he'd define the term microclimate as "the suite of climatic conditions (temperature, rainfall, humidity, solar radiation) measured in localized areas, typically near the ground and at spatial scales that are directly relevant to ecological processes."</p><p>We'll talk about that last bit in a minute. But first, there's another criteria to discuss. According to some researchers, a microclimate — by definition — must differ from the larger area that surrounds it.</p><p><a href="https://www.cfc.umt.edu/research/paleoecologylab/publications/Davis_et_al_2019_Ecography.pdf" target="_blank">Forests</a> provide us with some great examples. "The climate near the ground in a tropical rainforest is dramatically different from the climate in the canopy 50 meters [164 feet] above," says University of Montana ecologist <a href="https://www.cfc.umt.edu/personnel/details.php?ID=1110" target="_blank">Solomon Dobrowski</a> in an email. "This vertical gradient among other factors allows for the staggering biodiversity we see in the tropics."</p><p>Likewise, scientists observed that a 2015 partial <a href="https://animals.howstuffworks.com/insects/bees-stopped-buzzing-during-2017-solar-eclipse.htm" target="_blank">solar eclipse</a> caused the air temperature of an Eastern European meadow to <a href="https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.2802" target="_blank">change more dramatically</a> than it did in a nearby forest. That's because trees provide not only shade, but their leaves also reflect solar radiation. At the same time, forests tend to reduce wind speeds.</p><p>All those factors add up. A 2019 review of 98 wooded places — spread out across five continents — found that forests are 7.2 degrees Fahrenheit (4 degrees Celsius) <a href="https://natureecoevocommunity.nature.com/posts/47363-forests-protect-animals-and-plants-against-warming" target="_blank">cooler on average</a> than the areas outside them.</p><p>Now if you hate the cold, don't worry; there's a cozy exception to the rule. According to that same study, forests are usually 1.8 degrees Fahrenheit (1 degree Celsius) warmer than the external environment during the wintertime. Pretty cool.</p>
A Bug's Life<p>When does a microclimate stop being, well, micro? In other words, is there a maximum size we should be aware of when discussing them?</p><p>Depends on who you ask. "In terms of horizontal scale, some have defined 'microclimate' as anything that is less than 100 meters [328 feet] in range," Jucker says. "I'm personally less prescriptive about this."</p><p>Instead, he says the "scale at which we want to measure [a particular] microclimate" ought to be "dictated" by the questions we're trying to answer.</p><p>"If I want to know how temperature affects the photosynthesis of a leaf, I should be measuring temperature at centimeter scale," Jucker explains. "If I want to know if and how temperature affects the habitat preference of a large, mobile mammal, it's probably more relevant to capture temperature variation across [tens to hundreds] of meters."</p><p>For instance, solitary plants have the power to generate itty-bitty microclimates. Just ask <a href="https://www.colorado.edu/geography/peter-blanken-0" target="_blank">Peter Blanken</a>, a geography professor at the University of Colorado, Boulder and the co-author of the 2016 book, "<a href="https://amzn.to/2XN6FT8" target="_blank">Microclimate and Local Climate</a>."</p>
The urban heat island effect is a good example of how microclimates work. NOAA
Microclimates on a Grand Scale<p>It's no secret that our planet is going through some rough times at the macro level. The global temperature is <a href="https://climate.nasa.gov/vital-signs/global-temperature/" target="_blank">climbing</a>; nine out of the <a href="https://www.noaa.gov/news/2019-was-2nd-hottest-year-on-record-for-earth-say-noaa-nasa" target="_blank">10 hottest years on record</a> have occurred since 2005. And by one recent estimate, roughly 1 million species around the world are <a href="https://ipbes.net/sites/default/files/2020-02/ipbes_global_assessment_report_summary_for_policymakers_en.pdf" target="_blank">facing extinction</a> due to human activities.</p><p>"One of the big questions that ecologists and environmental scientists are trying to answer right now is how will individual species and whole ecosystems respond to rapid climate change and habitat loss," says Jucker. "...To me, [microclimates are] a key component of this research — if we don't measure and understand climate at the appropriate scale, then predicting how things will change in the future becomes a lot harder."</p><p>Developers have long understood the impact small-scale climates have on our daily lives. <a href="https://science.howstuffworks.com/environmental/green-science/urban-heat-island.htm#pt0" target="_blank">Urban heat islands</a> are cities that have higher temperatures than neighboring rural areas.</p><p>Plants release vapors that can moderate local climates. But in cities, natural greenery is often scarce. To make matters worse, plenty of our roads and buildings have a bad habit of absorbing or re-emitting heat from the sun. <a href="https://www.google.com/books/edition/Microclimate_and_Local_Climate/LHUZDAAAQBAJ?hl=en&gbpv=1&bsq=urban%20heat%20island" target="_blank">Vehicle emissions</a> don't exactly help the situation.</p><p>Still, it's not like Boston or Beijing are thermal monoliths. Sometimes, the documented temperatures <a href="https://e360.yale.edu/features/can-we-turn-down-the-temperature-on-urban-heat-islands" target="_blank">within a single city</a> vary by 15 to 20 degrees Fahrenheit (8.3 to 11.1 degrees Celsius).</p><p>That's where metro parks and city trees come in. They have nice cooling effects on nearby neighborhoods. "Several cities around the world have developed programs to increase urban green spaces," says Blanken. "Tree planting programs and green roof programs, have been shown to lower surface temperatures, decrease air pollution and decrease surface water runoff (urban flash-flooding) in urban areas."</p>
An "explosive" wildfire ignited in Los Angeles county Wednesday, growing to 10,000 acres in a little less than three hours.
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By Jeff Berardelli
Note: This story was originally published on August 6, 2020
If asked to recall a hurricane, odds are you'd immediately invoke memorable names like Sandy, Katrina or Harvey. You'd probably even remember something specific about the impact of the storm. But if asked to recall a heat wave, a vague recollection that it was hot during your last summer vacation may be about as specific as you can get.
<div id="ecf36" class="rm-shortcode" data-rm-shortcode-id="c2dcc9d48a6cd61f247df1544539a783"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1290959314132361216" data-partner="rebelmouse"><div style="margin:1em 0">Naming heatwaves is a good idea—making the abstract concrete, the invisible visible. Why should hurricanes and wild… https://t.co/hDWgYb79Ob</div> — Ed Maibach (@Ed Maibach)<a href="https://twitter.com/MaibachEd/statuses/1290959314132361216">1596623660.0</a></blockquote></div>
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Thailand has a total population of 5,000 elephants. But of that number, 3,000 live in captivity, carrying tourists on their backs and offering photo opportunities made for social media.
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One of the challenges of renewable power is how to store clean energy from the sun, wind and geothermal sources. Now, a new study and advances in nanotechnology have found a method that may relieve the burden on supercapacitor storage. This method turns bricks into batteries, meaning that buildings themselves may one day be used to store and generate power, Science Times reported.
Bricks are a preferred building tool for their durability and resilience against heat and frost since they do not shrink, expand or warp in a way that compromises infrastructure. They are also reusable. What was unknown, until now, is that they can be altered to store electrical energy, according to a new study published in Nature Communications.
The scientists behind the study figured out a way to modify bricks in order to use their iconic red hue, which comes from hematite, an iron oxide, to store enough electricity to power devices, Gizmodo reported. To do that, the researchers filled bricks' pores with a nanofiber made from a conducting plastic that can store an electrical charge.
The first bricks they modified stored enough of a charge to power a small light. They can be charged in just 13 minutes and hold 10,000 charges, but the challenge is getting them to hold a much larger charge, making the technology a distant proposition.
If the capacity can be increased, researchers believe bricks can be used as a cheap alternative to lithium ion batteries — the same batteries used in laptops, phones and tablets.
The first power bricks are only one percent of a lithium-ion battery, but storage capacity can be increased tenfold by adding materials like metal oxides, Julio D'Arcy, a researcher at Washington University in St. Louis, Missouri, who contributed to the paper and was part of the research team, told The Guardian. But only when the storage capacity is scaled up would bricks become commercially viable.
"A solar cell on the roof of your house has to store electricity somewhere and typically we use batteries," D'Arcy told The Guardian. "What we have done is provide a new 'food-for-thought' option, but we're not there yet.
"If [that can happen], this technology is way cheaper than lithium ion batteries," D'Arcy added. "It would be a different world and you would not hear the words 'lithium ion battery' again."
One of the concerns about a warming planet is the feedback loop that will emerge. That is, as the planet warms, it will melt permafrost, which will release trapped carbon and lead to more warming and more melting. Now, a new study has shown that the feedback loop won't only happen in the nether regions of the north and south, but in the tropics as well, according to a new paper in Nature.
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By Jessica Corbett
A sheriff in Florida is under fire for deciding Tuesday to ban his deputies from wearing face masks while on the job—ignoring the advice of public health experts about the safety measures that everyone should take during the coronavirus pandemic as well as the rising Covid-19 death toll in his county and state.
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<div id="79024" class="rm-shortcode" data-rm-shortcode-id="4ac086eab58b9713f2ad777c40938252"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1293578984148606977" data-partner="rebelmouse"><div style="margin:1em 0">This actively puts peoples' lives at risk. https://t.co/GKF0Xgjyex</div> — CAP Action (@CAP Action)<a href="https://twitter.com/CAPAction/statuses/1293578984148606977">1597248238.0</a></blockquote></div>
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