Editor's note: Be sure to check back on ASU Now for this developing story, and the website Hawaiicoral.org as we provide further updates. Or follow us on social media: @hawaiicoral_org — @greg_asner — @ASU_GDCS @asunews — #coralbleaching2019
UPDATE: Oct 1, 2019
When oceans warm, how resilient are coral?
With increasingly warming waters becoming a global threat to coral reef health, efforts of the state of Hawaii have gained worldwide attention. And the community’s response to report bleaching and further stressors to the reefs has been integrated into the daily efforts of the Asner lab’s real-time research and monitoring.
“My team has created a novel way to understand the ecological impacts of coral bleaching events by integrating outreach and citizen science engagement with multi-scale field, airborne and satellite scientific measurements,” said Greg Asner, director of ASU’s GDGC. “The approach allows us to scale up from individual corals to vast reef regions like the Hawaiian Islands, while simultaneously engaging and educating the public on ways to help mitigate the most egregious impacts of climate change on coral reefs.”
The overall goal of Asner’s fieldwork during the warming event has been to untangle the complex three-way interactions between coral species, habitat and water depth governing coral reef ecosystems. Since the warming began in early September, scientists have observed that some coral species are better able to withstand higher sea temperatures while others quickly bleach. According to Asner, there is no clear pattern underlying this variation in response.
“We’ve long known that coral responses to marine heatwaves vary at a range of scales, from individual corals within a species, to different species and communities of corals, and up to ecosystem and regional level differences. But the ecological pattern has never been mapped out, and therefore, never understood at any substantive geographic scale anywhere in the world”
One of the goals of his team’s research is to uncover if coral survival rates correlate to where they are located and also in terms of water depth. He also aims to discern if some coral species are better adapted to enduring longer durations of warming than others since isolated regions of the Pacific are expected to experience the same kinds of heatwaves as happened during the 2015 warming event. The consequences for corals and other wildlife exposed to such long and slow periods of simmering remains a question that Asner hopes to answer.
Now, with his team hard at work performing daily and repeated measurements of ocean conditions, coral extent and coral health on the Big Island, Asner is beginning to unravel the puzzle.
First, based on the bleaching reports, an underwater vehicle he developed makes long (1-5 km) transects along the seafloor of the Big Island’s Papa Bay, taking high-resolution videos of corals while also collecting spectral and chemical information on corals, as well as depth and temperature of the water. While one of Asner’s teams focuses on the conditions at their main research sites in Papa, Honaunau, and Kiholo Bays on the Big Island, another team takes measurements along shorter transects at different locales across the Big Island, providing “spot checks” of the same ecological markers that could alert the team to impending bleaching conditions.
Next, the reefs are ready for their close-up. Robin Martin, an associate professor at the School of Geographical Sciences and Urban Planning, is leading an innovative 3D underwater photomapping endeavor.
First, Martin’s teams work across multiple bays across the Big Island, diving down to the seafloor to take thousands of photos. Next, they deploy structure-from-motion analysis technology, which puts together thousands of photos of corals from different angles to reconstruct the reefs into a composite 3D image.
For example, in just one circular 12-meter-diameter plot, up to ten different species of coral may coexist, with each responding to warming ocean temperatures in a uniquely observable way. By documenting corals in their before, during and after bleaching, Martin and her team will have a record of coral resilience throughout the 2019 marine heatwave event.
Given how popular Hawaii is as a destination for tourists and water recreational activities, investigating the localized human-driven toll on reef ecosystems is also woven into Asner’s multi-pronged research strategy. Asner’s PhD student, Rachel Carlson, measures water quality, also known as turbidity, and its relation to coral bleaching. Areas of low-quality water become contaminated due to run-off from the land, usually from homes, hotels and golf courses. These areas of low-quality water may intensify coral bleaching at nearby sites; as high temperatures in the Pacific extend into the holiday season, there will be more opportunities for Asner’s team to study coral ecosystems along high-traffic coastlines.
Lastly, to round out the picture of how ocean warming affects Hawaii’s ocean ecosystems, Asner’s team is also conducting an intensive study of fish and invertebrates to measure the rich biodiversity that corals support. Using fish camera traps that take one photo every ten minutes from dawn to dusk, the team is interested in how different species respond to bleaching conditions.
Previous research has shown higher coral survival rates in areas with dense fish populations. Marine heatwaves drive an overgrowth of algae, which ultimately causes coral bleaching and death. But fish can act like a coral fire and rescue team, springing into action to prune the algae overgrowth ----and save the corals. By essentially spying on the fish populations using the camera traps, Asner’s team will be able to find out if the environmental changes to the local ecosystem caused by the heatwave will also make the protective fish abandon their coral habitats.
Their research also has implications for how Hawaii manages its fishing policies; Hawaii is under intense fishing pressure, and if high fish counts improve coral resilience, then policies to curb fishing during bleaching events might also make sense.
"In the end, our multi-scale approach, which goes from individual corals to satellite-based maps of reef change, is about educating the public and providing actionable pathways to improve coral reef management in what will be repeated marine heatwaves driven by the climate crisis," said Asner. "Managing reefs, including their coral and fish populations, can no longer be done effectively without a new proactive management approach, which must be based on the multi-scale monitoring capability that we have pioneered."
-Written by Heather D'Angelo, communications director, Asner lab
UPDATE: Sept. 24, 2019
Ocean cauldron is creating widespread coral bleaching across Hawaii
In Hawaii, citizen scientists have sprung into action to help save the greatest source of ocean life diversity, its coral reefs during record breaking high temperatures this summer.
National Oceanic and Atmospheric Administration (NOAA) predicted in early August that there would be a widespread and severe bleaching event in the coming months after tracking a “blob” of warm water moving toward the Pacific, akin to one that triggered widespread bleaching in 2015.
Now, the blob has arrived.
This time, NOAA, the DLNR Division of Aquatic Resources (DAR), and the Arizona State University Center for Global Discovery and Conservation Science (ASU-GDCS) have joined forces to collaborate on coral reef science, conservation and management in Hawaii.
One of the outcomes of this partnership is the creation of a coral bleaching alert card, which depicts a list of six steps people can take to reduce any additional stress on corals during the current bleaching event.
ASU-GDCS research scientists recently hit the streets to distribute these cards to local dive and local tourist shops.
With a better-informed community, everyone is doing their part to help save the coral reefs.
The Governor’s office issued another statement to raise awareness, and last week, a team from DAR conducted a rapid assessment of coral health at Molokini and along Maui’s south shore from Makena to Maalaea.
The National Coral Reef Monitoring Program surveyed the Papahānaumokuākea Marine National Monument and found extensive bleaching. At Kure Atoll, the northernmost atoll in the archipelago, almost 100 percent of shallow-water corals (less than 15 feet deep) are bleached. Severe coral bleaching is predicted to extend across the Hawaiian Archipelago, and citizen science reports of bleaching have confirmed this widespread bleaching.
Russell Sparks, a DAR Aquatic Biologist reported, “Molokini is composed of high percentages of the coral species, Montipora capitata, and we found roughly 50% of this coral already bleached or paling heavily.” The DAR team found in waters off Makena, Wailea, and Kihei the percentage of corals showing bleaching currently at less than 10%.
Warm ocean temperatures are expected to persist in the coming weeks, likely worsening the coral bleaching that has recently been observed across the islands.
ASU-GDCS has been focused on monitoring on Hawaii’s Big Island, and has seen similar bleaching in the pristine waters of Papa Bay.
“We just finished installing 6 new fish camera traps in #Hawaii to monitor changes in fish communities during and after the bleaching event," said Greg Asner, director of ASU=GDCS. "We're geared up and ready to finish pre-to-early coral bleaching measurements as the ocean heatwave intensifies. Using fish camera traps, underwater temp sensors, and PLANET labs satelliate imagery, we're tackling coral reef research from above and from below."
Why are so many coming together to help save coral reefs?
For the sea, coral reefs are like the rain forests on land in their support of biodiversity (see https://blog.ted.com/nature-revealed-biodiversity-in-3d-greg-asner-at-tedglobal-2013/.
According to Hawaii’s Division of Aquatic Resources, https://dlnr.hawaii.gov/dar/habitat/coral-reefs/, even though coral reefs cover just a tiny fraction of the ocean floor, they support almost one-third of the world’s marine fish species. Yesterday, with alarming news of up to 3 billion, or almost one-third of the entire bird-population of North America lost due to human activity, the fear is that the oceans are next.
Sometimes corals are able to recover from bleaching. However, they can die if stressors, such as warmer ocean temperatures, continue. Studies have shown that if local stressors are reduced before, during, and after bleaching events, corals are more likely to recover. Local stressors include human impacts, such as unintentionally knocking over coral while snorkeling or diving, boat anchors hitting coral, unsustainable fishing practices, and pollution from nearby watersheds.
The State of Hawai‘i’s Department of Land and Natural Resources will introduce an initiative in October aimed at tour operators to inform their guests about good reef practices. Numerous operators, like FairWind Big Island Ocean Guides on Hawai‘i Island, are already educating people on their boats. They ask them not to stand on, sit on, or touch the reef and to use reef-safe sunscreen products.
Worldwide, about 400 million people depend on coral reefs for work, food and protection. Hawaii is no different. Yet every single reef could be gone or threatened by global heating and ocean heatwaves, especially if they become an annual event.
Sept. 3, 2019
Citizen scientists give first reports of widespread coral bleaching events across Hawaiian Islands
On Aug.23, after the Hawaii Gov. David Y. Ige’s office issued a plea for help dealing with a pending widespread and severe coral bleaching event during an ocean heatwave, early efforts have been focused on informing the community of how they can best help save the reefs.
Through word of mouth and social media efforts, the Hawaii state government, local tourism offices and dive and surf shops have been spreading the word to its citizen scientists of being the extra eyes on the reef to help state and federal managers monitor and best respond to the ongoing bleaching event.
“During the past eight days since the Governor’s Office announcement, there have been 62 reports of bleaching events coming from our citizen scientists,” said Greg Asner, who directs Arizona State University’s Center for Global Discovery and Conservation Science.
This past week, Asner has been in a series of emergency meetings with state and federal officials to help mitigate the harmful effects of the looming coral reef crisis.
ASU helped launch a citizen science and satellite tracking effort for sharing information and reporting coral bleaching. Quickly, Asner’s team created Hawaiicoral.org, a partnership between the Center for Global Discovery and Conservation Science (Twitter @ASU_GDCS), NOAA (@NOAA) and Hawaii's Division of Aquatic Resources (DAR), Planet (@planetlabs) and Allen Coral Atlas (@AllenCoralAtlas) to inform about coral reef bleaching in Hawaii and to galvanize action.
To help map incoming reports, the website offers an easy interactive tool for citizens to report the location and severity of bleaching events.
The map shows reports of moderate to severe bleaching already underway from out west on Kauai to the Big Island. Responding to these reports, GDCS scientists like Robin Martin and Patrick Gartrell have been measuring living and dying coral in preparation for the ocean heatwave (see: https://twitter.com/HawaiiCoral_Org/status/1168780178882990081?s=20).
The latest temperature update from NOAA offer little solace for relief for the coral reefs, as sea surface temperatures continue to rise toward the levels found during the worst mass bleaching event in 2015 (see: https://twitter.com/HawaiiCoral_Org/status/1168842078400499712?s=20).
For Hawaii’s communities, people are asked to be ready to get out to the reefs and help by reporting any bleaching Hawaiicoral.org. Please participate and spread the word. #coralbleaching2019 @asuresearch
Aug. 23, 2019
July ended with the hottest recorded average temperature since people have been making daily readings. With the warming, climate change is ensured. A huge chunk of Greenland has melted, Arctic seas have opened, and the diversity of life on Earth may be threatened.
Now, the effects are spreading across the Hawaiian Islands, with some of the most diverse and abundant life under peril due to a massive coral bleaching event underway.
According to NOAA scientist Jamison Gove, "Ocean temperatures are extremely warm right now across Hawaii, about 3°F warmer than what we typically experience in mid-August. If the ocean continues to warm even further as projected, we are likely to witness severe and widespread coral bleaching across the islands."
This event is coming a mere four years after the unprecedented bleaching events of 2014 and 2015. Just as the Hawaiian coral reefs were showing remarkable resiliency and making a recovery, they are faced with yet another event.
Coral bleaching is a change from normal coloration of browns, yellows and greens to a nearly white color. This change occurs when corals are stressed by environmental changes, especially temperature increases. Although corals can recover from moderate levels of heat, if it is prolonged, they will die.
But scientists say that reducing secondary stress on corals during these ocean heat waves can improve the chances of coral survival.
According to Division of Aquatic Resources (DAR) administrator Brian Neilson, “We know this bleaching event is coming, and it’s probably going to be worse than the one we experienced a couple of years ago, when West Hawaii experienced a 50% mortality rate and Maui experience 20-30% mortality rates on DAR fixed monitoring sites. We’re asking for everyone’s help in trying to be proactive and minimize any additional stress put on coral.”
As part of its sustainability commitment to help preserve life on Earth, Arizona State University is leading the effort to help Hawaiians save the reefs by providing real-time monitoring in support of DAR's efforts.
"The work that the team is doing here, in cooperation with DAR, is the first time on planet Earth that we are doing real-time monitoring of a bleaching event," said Greg Asner, who directs the new ASU Center for Global Discovery and Conservation Science.
Their suite of technology has extensively mapped the state of coral reef health before the warming event. Now, their heroic efforts will monitor the warming ocean’s impact on coral bleaching through space satellite imaging, 3D laser mapping from the air and sensors sunken on the ocean floor.
"The sea surface-temperature alert already went up, and this is the highest temperature ever recorded in Hawaii," Asner said. “But bleaching is not death, so there is still a chance to save the coral reefs.”
Asner mentions that what ultimately kills coral are algae, who thrive and multiply with the higher temperatures, gobbling up all the surrounding oxygen and snuffing out coral and ocean life.
DAR is working with the Hawaiian community on simple ways that they can specifically help:
• Avoid touching the reef while diving, snorkeling or swimming.
• Do not stand or rest on corals.
• Use sunscreens with no oxybenzone or octinoxate.
• Boaters should use mooring buoys, or anchor only in sand areas and keep anchor chains off the reef.
• Fishers should reduce or stop their take of herbivores, such as parrotfish, surgeonfish and sea urchins. Herbivores clear reefs of algae, which overgrow and kill corals during bleaching events.
• Taking extra precaution to prevent contaminants from getting to the ocean like dirt from neighboring earthwork, chemical pollution from fertilizers, and soaps and detergents getting to storm drains.
Together, through state agencies, ASU research and the community, they may help stem the tide on coral bleaching.