In the waters off the Hawaiian Islands, rates of calcification were measured in the deepest coral colonies and reported recently in a study published in Coral Reefs led by a University of Hawai‘i (UH) at Mānoa oceanographer.  

Reef building corals require light for photosynthesis to build the reef structure through calcification, but available light declines quickly with increasing water depth. Below about 200 feet, calcification rates for light-dependent corals had previously not been measured. 

Samuel Kahng, lead author and graduate affiliate faculty of oceanography in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST), reported the first calcification rates from corals (Leptoseris spp.) in Hawai‘i at depths of 230-360 feet. 

“In addition to being from the deepest coral analyzed, these are by far the lowest calcification rates ever measured for healthy, light-dependent corals in their natural habitat,” said Kahng. “These rates are 20-40 times slower than observed in shallow water corals.”

Leptoseris spp. dominate the coral community in deep, low-light zones throughout the Indo-Pacific region. This species of coral exhibits a strategic approach to expanding the surface area with which it captures downwelling light–they form very thin horizontal plate-like skeletons to maximize the area that can be built by their very low calcification rates. Kahng and colleagues published a previous study revealing that the lateral growth rates of these plate-like skeletons are unexpectedly high, given the low light availability. 

“The corals’ ability to quickly grow horizontal surface area is impressive, especially given the low calcification rates,” said Kahng. “What this points to is the incredibly efficient use of calcification.”

Vertical habitat

Because Hawai‘i has such clear water, coral reef ecosystems extend offshore to extreme depths, with specialized light-dependent coral communities as deep as 500 feet.

“Hawai‘i has much more vertical habitat compared to other coral reef ecosystems around the world,” said Kahng. “These deep ‘mesophotic’ coral ecosystems can cover more habitat area than shallow water coral reefs. However, the general public rarely see them, so they present unique ecosystem management and conservation challenges.”  

In future studies, Kahng and colleagues will continue to try to unlock the secrets that enable these deep corals to thrive using the limited light in one of the ocean’s least studied habitats.

Read also on The Garden Island, Big Island Now, ECO Magazine, UH News, Eurekalert, Phys.org and Kauai Now.

Born and raised on the island of Guam and having attended St. John’s School from the time she was in kindergarten, Nicole Sulla Mathews said coming to the University of Hawai‘i at Mānoa to pursue a bachelor’s degree was a major change in almost all aspects. One thing that didn’t change, however, was her longstanding interest in environmental science. 

“Ever since middle school, I have been interested in environmental science,” Mathews shared. “It started with water sampling but expanded to soil science, as well. I am very fortunate to have a great support system from my family and teachers at St.John’s and was provided with the great opportunity to take my science projects to island-wide and international science fairs.”

As an undergraduate student in the Global Environmental Sciences degree program in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST), Mathews completed a few oceanography courses and learned, for the first time, about research opportunities in that discipline. 

Mathews joined the Hawai‘i Ocean Time-series program for one of their monthly cruises, 60 miles north of O‘ahu at Station ALOHA. Onboard the cruise, she got first-hand experience with oceanographic sampling and testing, while helping the UH Mānoa oceanographers conduct their research.

“I loved being at sea and learning about ocean science,” said Mathews. “That led me to pursue a senior thesis focused on microbial oceanography.”

Working with UH Mānoa oceanography professor Angelicque White and researcher Fernanda Henderikx Freitas, Mathews analyzes images from an Imaging Flow Cytobot, a machine that captures images of microscopic organisms for identification of marine plankton. 

“Since our automated classifier is still learning how to accurately classify the organisms, I work on manually annotating and sorting taxa, ideally to the genus level,” said Mathews. “For my thesis, I am annotating images from the research cruises PARAGON 1 and 2 and will be looking for trends in different classes of microbes during various stages of algal blooms.”

“It is always a bit of a thrill to see someone first lay eyes on the wild diversity of microbial characters that allow our oceans to thrive” said White. “I get to see the outcomes but Fernanda Henderikx Freitas has been working directly with Nicole and others to create a training pipeline for students to quickly learn relevant taxonomic details about ocean plankton and help train our machine learning tools to see what we see. It’s an exciting time in the arc of ocean science.”

In addition to coursework and research, Mathews has been working in the SOEST Student Academic Services Office since November 2021. There, she interacts with current and prospective students, creates content for social media and graphics for the weekly undergraduate student newsletter, and organizes events. For her outstanding efforts, she was recently honored with a UH Mānoa Student Employee of the Year Award, which included a $750 cash scholarship. 

“I really enjoy meeting with prospective students and their families to talk about our school,” said Mathews. “It’s always fun to meet people from different places visiting UHM and getting to show students and families our campus and school.”

Following graduation in Spring 2024, she plans to pursue her teaching certification in secondary science. 

“My mom and brother are both teachers at my alma mater and I hope, sometime in the future, I will be teaching alongside them,” Mathews said. “I also want to continue in school and pursue a masters in oceanography where I can continue my undergraduate research and hopefully go back out to sea.”

Read also on UH News.

The Land Back movement has called for global solidarity to address the oppression and dispossession of Indigenous Peoples’ lands and territories. The alienation of Indigenous Peoples from Water has largely been absent from this call to action. However, there is a growing consensus among Indigenous Water Protectors who assert that there cannot be Land Back without Water Back.

In a collaborative response to this emerging movement, an international group of Indigenous researchers, including two from the University of Hawai‘i at Mānoa, led by Dr. Kelsey Leonard, professor in the Faculty of Environment at the University of Waterloo and Canada Research Chair in Indigenous Waters, Climate and Sustainability, have offered a definition of Water Back as it relates to Water research.  

For the Indigenous author team, for communities, and within the primarily English-language, Indigenous-oriented and -produced research, Water Back means the return of Water and kin to Indigenous governance in a way that empowers the resurgent Indigenous Water relationships that are integral to Indigenous cultural, biological, spiritual, and political sovereignty; this includes cosmogony, ceremony, access, law, and policies. 

“In articulating a Water Back framework that draws primarily from Indigenous scholarship, our author collective provides perspectives and resources that the scientific community can readily access and implement into their own research,” said Dr. Rosie Alegado, co-author of the review paper published in Water Alternatives recently, associate professor of Oceanography in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST), and director of the Ulana ‘Ike Center of Excellence at the University of Hawai‘i Sea Grant College Program.  

The co-authors conducted a first-of-its-kind, comprehensive review of Indigenous Water literature—analyzing more than 419 published journal articles, government reports, and official documents and identified Water Back themes such as cosmology and governance, colonialism, justice, responsibilities and rights, health, and climate change. Their unique approach grows the scholarly movement to empower Indigenous research methods. 

“The paper provides a valuable entry point for learning about Indigenous Water that is both grounded in Indigenous scholarship and that balances cross-cutting themes with the specifics of a diversity of cases and contexts,” said Dr. Aurora Kagawa-Viviani, co-author and assistant professor at the Water Resources Research Center and Department of Geography and Environment in the UH Mānoa College of Social Sciences. 

Water Back is allowing Water to rematriate relationships with Indigenous Peoples, the Lands that are nourished by Water, and the more-than-human relatives that live within and care for Water. Water Back is the restoration of humanity’s responsibility to care for Water and the recognition of Indigenous Peoples’ inherent relationships, connections, rights, and responsibilities to Water.

“The definition advances a holistic conceptualization, offering an important framework centring Indigenous ways of knowing, doing, and being as a foundation for advancing Indigenous Water research,” said Leonard. “The framework also represents a collective of Indigenous Water researchers “restorying” how Indigenous Water research relationships are created or rematriated for the protection of the Water, the planet and future generations.”

The authors’ review and definition advance a holistic conceptualization of Water Back as a framework for future research sovereignty, focusing mainly on instances in Canada, Australia, Aotearoa New Zealand, and the United States. It has drawn international attention from water scientists foregrounding Indigenous intergenerational knowledge of weather, Water, and Land as being crucial to both the understanding of historical climate changes and the shaping of healthy future lifeways. 

Another significant outcome of the work was recognition that a database specifically dedicated to Indigenous Water research literature was absent. In response, the team made the decision to create and maintain a comprehensive database of the literature they reviewed. The database is now accessible for everyone to use and, starting in the fall of 2023, contributions will be welcomed from individuals or communities globally.

Portions of this content are courtesy of University of Waterloo.

It is with heavy hearts that we continue to hear about the tragedy that has hit Maui. The unfolding news of the devastating fires has left us all deeply affected, as we witness the separation, loss, and uncertainty faced by our friends and loved ones.

During this catastrophic and traumatic time on Maui and across the Hawaiian Islands, many are seeking to understand the factors that led to the destructive wildfires. While there is still much that remains unknown, SOEST and University of Hawai‘i scientists have shared with local and national news outlets the current understanding of how atmospheric, environmental, and historical conditions contributed to the tragedy. Below is a list of links to some of that information. 

Fire exposes flaws in Hawaii’s defenses against climate shocks in The New York Times
How severe weather fanned the flames in Lāhainā, and what to expect in the future on Hawai’i Public Radio
Complex origins of the Maui wildfire: Colonialism and climate change in The Messenger
withChip Fletcher, SOEST interim Dean and professor of Earth sciences

Why Hawaii’s wildfires are so devastating — and ‘predictable’ in the Washington Post
Maui fires not just due to climate change but a ‘compound disaster’ in the Washington Post
with Alison Nugent, associate professor of atmospheric sciences

The role climate change has played in Hawaii’s devastating wildfires on National Public Radio
with Giuseppe Torri, assistant professor of atmospheric sciences

Maui’s fire became deadly fast. Climate change, flash drought, invasive grass and more fueled it on Associated Press
Devastating Hawaii fires made ‘much more dangerous’ by climate change in The Guardian
withPao-Shin Chu, professor of atmospheric sciences and Hawai‘i State Climatologist

What fuels Hawaiʻi wildfires? UH expert explains on UH News
with Clay Trauernicht, UH Mānoa wildfire expert 

The science behind the Hawai’i fire on BBC’s Science in Action
As Maui looks to rebuild, climate change and drought fears are top of mind on NBC News
Hawaii’s climate future: Dry regions get drier with global warming, increasing fire risk
on The Conversation
with Kevin Hamilton, professor emeritus of atmospheric sciences

In these trying times, it is crucial that we stand together as an ‘ohana, providing solace, support, and compassion to one another. We extend our heartfelt condolences to those who have suffered losses and express our deepest empathy for those grappling with the uncertainty of the situation. 

How to help Maui ʻohana affected by wildfires on UH News
List of organizations accepting donations

Reducing land- and sea-based human impacts supports coral reef persistence in our changing climate, according to a study published recently in Nature and co-authored by Chelsie Counsell and Ning Li, researchers in the University of Hawai‘i at Mānoa School of Ocean and Earth Science and Technology. 

Coral reefs are among the most productive and biologically diverse ocean ecosystems on Earth. Many human communities depend on local tropical coral reefs for cultural practices, fisheries, and coastal protection. Unfortunately, coral reefs are threatened by the combined effects of land-based impacts such as wastewater pollution and urban runoff; sea-based impacts, including fishing pressure; and global climate change. 

While a coupled land-sea approach has been the guiding paradigm of coral reef conservation for decades, the potential effectiveness of managing land and sea together rather than in isolation has been difficult to test and remained unclear.

“Our research finds that simultaneously reducing local land- and sea-based human impacts benefits coral reef ecosystems under ocean warming,” said Jamison Gove, a research oceanographer with NOAA’s Pacific Islands Fisheries Science Center, UH Mānoa alumni, and co-lead of the study.

Land-Sea Connections

The research was conducted in the Hawaiian Islands, where 85 percent of people live within a few miles of the coast. But Hawaiʻi also has long stretches of remote coastline that remain undeveloped. This gradient in human population and coastal development makes it an ideal location to test how differences in local land-sea human impacts influence coral reefs over time.

The team of researchers used 20 years of high-resolution data on local human impacts and repeated underwater surveys of corals and reef fish from the same reefs to detect and document ecosystem change. 

They discovered that on some surveyed reefs, coral cover increased over time—a positive indicator of reef ecosystem health—whereas on others, it decreased. The study showed that the difference between these opposing trajectories in reef health was their local conditions. Reefs with the lowest levels of land-based impacts and increased fish populations (particularly herbivorous fish that primarily feed on algae), had a positive trajectory in coral cover. 

An unprecedented event

“The 2015 marine heat wave in Hawai‘i was unprecedented in the region—nothing comes close in more than a century of recorded temperature data,” said Gove. “As a consequence, many reefs experienced severe bleaching and extensive coral death. But to our surprise, we found that coral cover was unchanged at nearly 20 percent of the reefs in our study. Which raises the question: Why did some reefs fare better than others despite experiencing similarly extreme levels of heat stress?” 

The 20-year study period encompassed a significant marine heatwave in Hawaiʻi which allowed the team to assess coral response to severe heat stress. 

Once again, the researchers found that local land-sea conditions mattered. Reefs with the lowest levels of land-based stressors and increased fish populations had reduced coral loss during the marine heatwave.

A path to recovery

The researchers also assessed the influence of local conditions on coral reef ecosystem health for 4 years following the 2015 marine heatwave. They measured how much of the reef floor was covered by organisms that build reefs by depositing calcium carbonate, specifically hard corals and encrusting algae that help cement the reef together. Collectively known as reef-builders, these organisms represent an indication of ecosystem recovery following a major disturbance.

Again, the researchers found that local land-sea conditions influenced reef ecosystem health. Reefs with the highest cover of reef-builders had the lowest levels of wastewater pollution and had abundant populations of herbivorous fish known as “scrapers.” Scrapers, which primarily are parrotfish (uhu) in Hawaiʻi, are an aptly named group of reef fish as they literally scrape the reef with their teeth while eating. 

They found that coupling land- and sea-based resource management led to a positive outcome. It resulted in a far greater probability of a reef having a high cover of reef-builders four years after the marine heatwave than if either land or sea were managed in isolation.

“The notion that land and sea are interconnected is deeply rooted in indigenous Hawaiian stewardship practices,” said Gove. Traditional Hawaiian resource management stretched from the mountains (mauka) to the sea (makai) and was inclusive of the entire watershed, or ahupuaʻa. “Our findings support the need for reintegrating both land and sea within coastal ocean management, akin to long-standing indigenous management of island ecosystems.”

The study was led by the NOAA Pacific Islands Fisheries Science Center and Bangor University. This collaborative effort also included Arizona State University, NOAA Pacific Islands Regional Office, University of Hawaiʻi, National Park Service, SymbioSeas, University of Rhode Island, The Nature Conservancy, Cooperative Institute for Marine and Atmospheric Research, State of Hawaiʻi Department of Health, and the State of Hawaiʻi Division of Aquatic Resources.Portions of this content are courtesy of NOAA Pacific Islands Fisheries Science Center.

The biodiversity of the world’s oceans faces many threats such as climate change, invasive species, and more. President Joe Biden’s administration selected Kawika Winter, biocultural ecologist at the University of Hawaiʻi at Mānoa’s Hawaiʻi Institute of Marine Biology (HIMB) and director of the Heʻeia National Estuarine Research Reserve (NERR), to serve on the Ocean Research Advisory Panel (ORAP), which provides independent recommendations to the federal government on matters of ocean policy.

Winter and 17 other members were selected by a public nomination process facilitated by the Ocean Policy Committee and then appointed by the director of the White House Office of Science and Technology Policy and the chair of the Council on Environmental Quality. Members of ORAP represent the views of ocean industries, state, tribal, territorial or local governments and academia. They began their appointment on August 1 and will serve for three years.

“America has a long history of inflicting injustices on Indigenous Peoples. The Biden Administration, however, represents a major shift in this history by elevating Indigenous Knowledge (IK) through its memos regarding the incorporation of IK into research, policy and decision making,” said Winter. “However, it takes more than memos to bring about institutional change. We need IK advocates in decision-making positions to bring to fruition the changes that this administration is calling for. My goal is to use my lived and professional experiences to help the Biden Administration translate Indigenous wisdom into policy.”

Winter is an assistant professor whose primary appointment is with HIMB managing the Heʻeia NERR. His other appointments at UH Mānoa include life sciences (botany) and natural resources and environmental management. Winter earned his bachelors, masters and doctorate degrees in botany from UH Mānoa.

According to Winter, the Heʻeia NERR is one of the nation’s leading models for the integration of Indigenous knowledge in research, policy and decision making. Since its designation in 2017, this NERR has become one of the best examples of how NOAA can be responsive to the needs of Indigenous Peoples through collaborative management and collaborative research. His own research is focused on understanding the ecological foundations of Indigenous resource management.

Read also on UH News, EcoMagazine, Marine Technology News, and The Maritime Executive.

A biogeographical boundary—a transition zone that divides soft-bodied and shelled creatures—was discovered at the bottom of the North Pacific Ocean, according to a study co-authored by Craig Smith, oceanographer at the University of Hawai‘i at Mānoa.

This limit separates two distinct biological areas across the Clarion-Clipperton Zone (CCZ), a vast abyssal plain region extending over 3,000 miles between Mexico and Kiribati, at depths between 11,000 to 20,000 feet (3,500 to 6,000 meters), and which is currently targeted for deep-sea mining.

The study, published in Nature Ecology and Evolution, also revealed that there is a surprising increase in diversity with depth in this region, challenging the long-held paradigm in deep-sea ecology that biodiversity is limited by the harsher living conditions in deeper areas of the ocean.

“These results are really important because they show the abyssal seafloor communities in areas targeted for deep-sea mining are highly biodiverse and more heterogeneous than expected,” said Smith, a professor emeritus in the Department of Oceanography at the UH Mānoa School of Ocean and Earth Science and Technology. “The dramatic shift in abyssal seafloor communities over a depth change of only 500 meters [~1600 feet]means that mining large seafloor areas for polymetallic nodules may lead to higher risks of species extinctions that previous appreciated.”

Water chemistry shapes deep sea community

Erik Simon-Lledó, deep-sea ecologist at the National Oceanography Centre (NOC; UK) and lead author on the paper, said, “We were surprised to find a deep province so clearly dominated by soft anemones and sea cucumbers and a shallow-abyssal where suddenly soft corals and brittle stars were everywhere.”

The study suggests water chemistry, specifically the saturation of calcium carbonate, the mineral that forms the shells and skeletons of many animals, might be an overlooked factor in delineating this boundary and therefore key in shaping biodiversity across this vast area.

“Muddy abyssal seafloors were initially considered to be almost ‘marine deserts’ when first explored many decades ago, given the extreme conditions for life there—with a lack of food, high pressure, and extremely low temperature,” Simon-Lledó added. “But as deep exploration and technology progressed, these ecosystems keep unveiling a large biodiversity, comparable to that in shallow water ecosystems, only found on a much wider spatial spread.”

Informing deep-sea mining policies

“We have known for some time that the abyssal plains are relatively high in biodiversity,” said Adrian Glover, principal scientist at the National History Museum and co-author of the study. “What has been missing is knowledge of how that diversity is distributed and how it changes across broad spatial scales. These new data revolutionise our understanding of abyssal Pacific biogeography and will be vital to inform urgent policy decisions on potential deep-sea mining.”

Daniel Jones, principal scientist at the NOC and senior co-author of the study, said, “The research findings are the result of a ten year-long study in collaboration with more than 13 world-leading deep-sea research institutions, universities, and industry bodies, and involved 21 deep sea researchers. It shows the value of international collaboration in uncovering unknown patterns across huge areas of the ocean.”

The study showcases the patterns and processes that underpin deep ocean’s biodiversity, and how these differ between shallower and deeper regions in a vast abyssal nodule field habitat that is currently targeted for mining. This provides a new basis for regional-scale management strategies to protect biodiversity in Earth’s largest biome.

* * *

The research institutions involved in this work include: Natural History Museum (London), the German Centre for Marine Biodiversity Research (Senckenberg am Meer), the Ocean & Earth Science department (University of Southampton), the Marine Science Institute (University of California), the Department of Marine Sciences (University of Gothenburg), Korea’s Institute of Ocean Science and Technology, the Deep Sea Conservation Research Unit (University of Plymouth), the Marine Biology Research Group (Ghent University), the Institute of Marine Sciences (Okeanos, University of the Azores) and the Department of Oceanography (University of Hawai‘i at Mānoa).

Read also on UH News, Science, NOC News, Natural History Museum (London) News, and Science Alert.

Kamaʻehuakanaloa (formerly Lōʻihi Seamount), a submarine Hawaiian volcano located about 20 miles off the south coast of the Big Island of Hawai‘i, has erupted at least five times in the last 150 years, according to new research led by Earth scientists at the University of Hawai‘i at Mānoa. For the first time, scientists were able to estimate the ages of the most recent eruptions of Kamaʻehu, as well as the ages of eight additional older eruptions at this volcano going back about 2,000 years. Their findings were published recently in Geology. 

Hawaiian volcanoes are thought to transition through a series of growth stages. Kamaʻehu is currently in the earliest submarine “pre-shield” stage of growth, whereas the active neighboring volcano Kīlauea is in its main shield-building stage. 

“Kamaʻehu is the only active and exposed example of a pre-shield Hawaiian volcano,” said Aaron Pietruszka, lead author of the study and associate professor in the Department of Earth Sciences at the UH Mānoa School of Ocean and Earth Science and Technology (SOEST). “On the other Hawaiian volcanoes, this early part of the volcanic history is covered by the great outpouring of lava that occurs during the shield stage. Thus, there is great interest in learning about the growth and evolution of Kama‘ehu.”

Kama‘ehu’s eruption history

Previously, the only known and confirmed eruption of Kamaʻehu was the one that occurred in 1996, an event that was only discovered because it coincided with a large swarm of earthquakes that were detected remotely by seismometers on the Big Island.

“Seismometers can only be used to detect the ongoing active eruptions of submarine volcanoes because earthquakes are transient,” said Pietruszka. “In order to determine the ages of older eruptions at Kamaʻehu, we took a different approach. We used a mass spectrometer to measure tiny amounts of the isotope radium-226 in pieces of quenched glassy lava that were sampled from the seafloor outcrops of Kamaʻehu using a submersible.”

Magma naturally contains radium-226, which radioactively decays at a predictable rate. So, Pietruzska and co-authors used the amount of radium-226 in each sample to infer the approximate time elapsed since the lava was erupted on the seafloor, that is, the eruption age of the sample. 

Pietruszka started this investigation many years ago as a postdoctoral researcher at the Carnegie Institution for Science, just after finishing his doctoral degree in Earth science from SOEST. Once he returned to UH Mānoa in 2019, he got access to submersible dive videos and photos around Kama‘ehu and had the information he needed to finish connecting the dots.

“The submersible dive images and videos provided independent confirmation of our estimates of eruption ages,” said Pietruszka. “The lavas with the freshest appearance also had the most radium-226, and vice versa for the lavas with the ‘older’ appearance, that is, fractured and broken, and/or covered with marine sediment. I was surprised to discover that Kama’ehu had erupted five times within the last ~150 years, which implies a frequency of ~30 years between eruptions at this volcano. This is much slower than at Kīlauea, which erupts almost continuously (with infrequent pauses of only a few years).”

Chemical changes in lava

The chemistry of the lava erupted from Hawaiian volcanoes changes over time. The new eruption ages for the lavas from Kama‘ehu, coupled with measurements of lava chemistry, reveal that the timescale of variation in lava chemistry at this pre-shield volcano is about 1200 years. In contrast, Kīlauea lava chemistry changes over a timescale of only a few years to decades, with a complete cycle over about 200 years. 

“We think that the origin of this difference is related to the position of the two volcanoes over the Hawaiian hotspot,” said Pietruszka. “This is an area of Earth’s mantle that is rising toward the surface—a “mantle plume” that ultimately melts to form the magma that supplies Hawaiian volcanoes.  Models and other isotope data from thorium-230 suggest that the center of a mantle plume should rise faster than its margin.  Our results—specifically, the factor of six longer timescale of variation in lava chemistry at Kama’ehu—provides independent confirmation of this idea.”

The research team hopes to better understand how Hawaiian volcanoes work from their earliest growth stages to their full, and frequently active, maturity to help them understand the deep controls on volcanic eruptions that initiate within the mysterious, upwelling mantle plume under the Hawaiian hotspot. 

Read also on KHON2, Newsweek, Big Island Now, Coastal News Today, Science Daily, UH News, Phys.org, Eurekalert, and The Garden Island.