Honolulu threatened by climate change

In Hawai‘i, natural landmarks fill the role of the mainland’s cardinal directions. That means saying a place is toward the mountains (mauka) or toward the sea (makai) but also, if you’re in Honolulu, toward or away from iconic Diamond Head, the volcanic ridge that steals the skyline from neighboring Waikiki Beach, where a less natural feature—the Ala Wai Canal—defines the area.

Two miles long, palm-lined and stick-straight, the broad channel is the culmination of the Ala Wai Watershed, which runs from a high point in the Ko‘olau Mountains all the way down to Waikīkī Beach. Almost all the rain that is not absorbed by the ground in this urban watershed—which encompasses eight of Honolulu’s densest neighborhoods, is home to more than 160,000 people and welcomes additional 71,000 visitors every day—flows through the canal.

Meanwhile, global sea level rise is accelerating at its fastest rate in 28 centuries, a study in Proceedings of the National Academy of Sciences reported earlier this year; by 2100, average global sea level is expected to rise between 1 and 6 feet. The latest projections, published in Nature in March, suggest that more than 13 million people may be at risk in the continental United States alone. In Hawai‘i, as the sea level rises, the rainwater that flows rapidly down from the mountains will encounter a kind of traffic jam once it hits the canal. “You have all this water coming down the watershed and no place for it to go,” says Chip Fletcher, Associate Dean for Academic Affairs and Professor of Geology and Geophysics (G&G), and leader of the Coastal Geology Group (CGG).

NASA now has new options for sampling Moon’s ancient interior

Finding and sampling the Moon’s ancient interior mantle — one of the science drivers for sending robotic spacecraft and future NASA astronauts to the Moon’s South Pole Aitken basin — is just as likely achievable at similar deep impact basins scattered around the lunar surface. At least that’s the view reached by planetary scientists who have been analyzing the most recent data from NASA’s Gravity Recovery And Interior Laboratory (GRAIL) and its Lunar Reconnaissance Orbiter (LRO) missions as well as from Japan’s SELENE (Kaguya) lunar orbiter.

The consensus is that the lunar crust is actually thinner than previously thought. If so, this would have made it easier for large impactors of the sort that carved out the near side’s Crisium impact basin, the far side’s Moscoviense impact basin and the Aitken basin to also have excavated some of the Moon’s geologically-compelling early mantle.

Sampling a range of mantle compositions would allow us to test models for crystallization and composition of the Moon’s original molten magma ocean, [said] Jeff Taylor, a planetary scientist at the Hawai‘i Institute of Geophysics and Planteology (HIGP). But he says the real problem is that pure mantle rock might not be present. “Besides being melted it might be mixed with crustal material, giving us a mixed composition. That is not uninteresting, but makes the job of deciphering lunar mantle dynamics and composition difficult.”

Protecting diversity on coral reefs: DNA may hold the key

Coral reefs are widely known for their stunning array of color, shape and forms of life, making them a model for extreme biodiversity. Hidden within the multitude of reef inhabitants, but no less important, is their genetic diversity— variability in DNA that gives species the capacity for adaptation, speciation and resilience in the face of stress.

Research published on April 27 by a team of scientists from SOEST, the University of California, Santa Barbara (UCSB), University of St. Andrews and University of Melbourne discovered that large areas of intact coral reef with extensive live coral cover, not disturbed by humans or climate change, harbor the greatest amount of genetic diversity.

The team, led by Kimberly Selkoe, associate researcher at the UH Mānoa Hawaiʻi Institute of Marine Biology (HIMB) and UCSB, assessed genetic diversity from more than 17,000 samples taken from 47 common reef-associated species across the Hawaiian Archipelago. With this work, the researchers uncovered a link between species diversity of an ecosystem and the genetic diversity encoded within the DNA of those species.

Read more about it in the UH System News and listen to the interview with Kim Selkoe at Hawaii Public Radio.

UPDATE: See the article discussing this research in the Proceedings of the National Academy of Sciences.

Coral toolkit allows floating larvae to transform into reef skeletons

In a study published in the Proceedings of the Royal Society B, researchers from UH Mānoa, Rutgers University, and the University of Haifa identified key and novel components of the molecular “toolkit” that allow corals to build their skeletons (called biomineralization) and described when—in the transformation from floating larvae to coral skeleton—these components are used.

Corals are the sum of a symbiotic relationship between cnidarian animals and millions of single-celled algae that live inside their tissues. These symbiotic algae photosynthesize and provide the energy corals need to build their skeletons. In turn, the skeletons form the structure and framework of coral reefs that provide habitat to fishes and other animals. Coral reef are so large they can be seen from space, and generate goods and services valued on the order of billions of dollars annually.

“Our research on reproduction in the lace coral, Pocillopora damicornis, provided the perfect opportunity to look at a natural on-off switch in coral biomineralization,” said co-lead author,” Hollie Putnam, Hawai‘i Institute of Marine Biology (HIMB) assistant researcher. Corals release their offspring as swimming larvae with no skeleton. The larvae change shape, settle onto the reef, and start to build their skeletons. Putnam and Ruth Gates, senior researcher and director of HIMB, collaborated with scientists from Rutgers University, and the University of Haifa to examine gene expression and the production of proteins at these different life stages.

Read more about it in the UH System News and at Science Codex.

Microbial takeover on coral reefs?

Coral reefs—the world’s most productive and diverse marine ecosystems—rely on a masterful recycling program to stay healthy. The corals and algae that form the base of the reef’s food web release a variety of nutrients that support a complex and efficient food chain. But when this system gets out of whack, the cycle breaks down and endangers the coral reef’s health. A new study led by researchers at San Diego State University (SDSU) and co-authored by assistant professor Craig Nelson at the Center for Microbial Oceanography: Research and Education (C-MORE) explores how a process called microbialization destroys links in this delicate food chain.

Millions of people around the world depend on coral reefs to provide productive fisheries and they play an important role in global environmental health. Overfishing the waters near reefs, however, removes the primary consumers of algae, allowing fleshy algae to spread unchecked. In areas with large human populations, pollution often exacerbates the problem by stimulating the algae.

Fleshy algae on reefs exude copious amounts of nutrients known as dissolved organic carbon (DOC), which microbes eat. Researchers theorized that when reef ecosystems have elevated levels of algae producing meals for microbes, higher levels of potentially harmful microbes can occur throughout the reef ecosystem. In this newly abundant population of microbes, evolutionary selection pressures favor microbes that endanger corals, either by depleting oxygen from the environment or through disease.

Read more about it in the UH System News.

Research expedition blog online: climate change and Antarctic fjord ecosystem

Follow the research activities of scientists with the FjordEco project (from SOEST, Scripps Institution of Oceanography and the University of Alaska at Fairbanks) as they study fjord ecosystem dynamics in Antarctica.

Marine communities along the Western Antarctic Peninsula (WAP) are highly productive ecosystems which support a diverse assemblage of charismatic animals such as penguins, seals, and whales as well as commercial fisheries including for Antarctic krill. The WAP also contains many fjords (deep estuaries carved by glacial ice) with active glaciers entering the ocean; these fjords appear to be intense, potentially climate sensitive, hotspots of biological production and biodiversity. Because of intense biological activity and abundant charismatic fauna, these fjords are also major destinations for a large Antarctic tourism industry. Nonetheless, the structure and dynamics of these fjord ecosystems are very poorly understood.

Craig Smith and graduate student Astrid Leitner of UH sorting animals from the Blake trawl in the wee hours of a cold night.

The FjordEco project is an integrated field and modeling program designed to evaluate physical oceanographic processes, glacial inputs, water column community dynamics, and seafloor bottom community structure and function in these important yet little understood fjord systems. These Antarctic fjords have characteristics that are substantially different from well-studied Arctic fjords, likely yielding much different responses to climate warming. FjordEco is designed to provide major new insights into the dynamics and climate sensitivity of Antarctic fjord ecosystems, highlighting contrasts with Arctic sub-polar fjords, and potentially transforming our understanding of the ecological role of fjords in the rapidly warming west Antarctic coastal marine landscape.

New imaging technique reveals vulnerability of coral reefs

Corals, the primary reef builders on coral reefs, are often the star player in research studies addressing the impacts of climate change on coral reefs because they are the foundation of coral reef ecosystems. However, the breakdown of coral reefs from borers (such as bivalves, sponges, and marine worms) and grazers (such as parrotfish and urchins)—called bioerosion—and growth from encrusting algae and invertebrates (for example, oysters and barnacles)—called secondary accretion—are critical processes for reef sustainability.

In a study published on 13 April 2016 in PLOS ONE, Nyssa Silbiger and colleagues created a novel method to expose how these underdogs of coral reef science respond to varying environmental conditions, including changing ocean acidity. Using µCT (micro-computed tomography) scans, Silbiger and colleagues were able to calculate detailed bioerosion and secondary accretion rates on coral reefs—work she performed as a graduate student at the Hawaiʻi Institute of Marine Biology (HIMB).

Read more about it in the UH System News.

Piggybacking viruses

In the microscopic life that thrives around coral reefs, a team of researchers, including Katie Barott, postdoctoral researcher at the Hawaiʻi Institute of Marine Biology, have discovered an interplay between viruses and microbes that defies conventional wisdom. As the density of microbes rises in an ecosystem, the number of viruses infecting those microbes rises with it. It has generally been assumed that this growing population of viruses, in turn, kills more and more microbes, keeping the microbial population in check. It’s a model known as “kill-the-winner”—the winners being the blooming microbial cells and the killers being the viruses (mostly bacteria-killing viruses known as bacteriophages) that infect them.

However, previous research has suggested that, under certain conditions, viruses can change their infection strategy. As potential host microbes become more numerous, some viruses forego rapid replication and opt instead to reside peaceably inside their host, thereby reducing the viruses’ numbers. In a study published recently in the journal Nature Barott, along with lead authors Ben Knowles and Cynthia Silveira, both in Forest Rohwer’s lab at San Diego State University, and co-authors refer to this alternative model as “piggyback-the-winner,” and it could have implications for phage-based medicine and ecosystem resilience in the face of environmental disturbances that promote microbial blooms.

Read more about it in the UH System News.

SOEST receives new marine facility

SOEST has received the ceremonial key to its new marine facility at Pier 35 today from the State of Hawaiʻi Department of Transportation.

The transportation department along with elected officials and UH representatives conducted a blessing and ceremony to formally convey the newly renovated Pier 35 facility to SOEST. The $17-million project involved partial demolition and renovations to the Pier 35 building. The UH Marine Center will relocate from its current location at Pier 45 of Honolulu Harbor by summer 2016. The move is part of the Department of Transportation’s Harbors Modernization Plan to increase container terminal space at the state’s busiest commercial harbor.

UH operates two major research vessels, the R/V Kilo Moana and the R/V Kaʻimikai-O-Kanaloa, as well as several small boats, manned submersibles, remotely operated, autonomous and towed underwater vehicles and ocean gliders. Many of the research cruises and marine operations are done in collaboration with other specialized research groups and programs at UH.

“This is a new page in the centennial history of marine science at the University of Hawaiʻi,” said SOEST Dean Brian Taylor. “It’s a great day with a new facility, new building and a renovated pier.”

Read more about it and watch the video report in the UH System News and at KHON2.

Human carbon release rate is unprecedented in the past 66 million years

The earliest instrumental records of Earth’s climate, as measured by thermometers and other tools, start in the 1850s. To look further back in time, scientists investigate air bubbles trapped in ice cores, which expands the window to less than a million years. But to study Earth’s history over tens to hundreds of millions of years, researchers examine the chemical and biological signatures of deep sea sediment archives.

New research published on 21 March 2016 in Nature Geoscience by Richard Zeebe, professor of Oceanography, and colleagues looks at changes of Earth’s temperature and atmospheric carbon dioxide (CO₂) since the end of the age of the dinosaurs. Their findings suggest humans are releasing carbon about 10 times faster than during any event in the past 66 million years.

The research team developed a new approach and was able to determine the duration of the onset of an important past climate event, the Paleocene-Eocene Thermal Maximum, PETM for short, 56 million years ago. “As far as we know, the PETM has the largest carbon release during the past 66 million years,” said Zeebe.

Read more about it in the UH System News, Reuters, the Washington Post, the BBC, National Geographic, the Guardian, and the National Science Foundation; read more about it and watch the video report at Hawaii News Now.