Review
Geochemistry & Geophysics
Craig E. Nelson, Linda Wegley Kelly, Andreas F. Haas
Summary: To survive in nutrient-poor waters, coral reefs depend on efficient retention and recycling of materials. This review focuses on microbial processes that contribute to the persistence and stability of coral reefs, particularly the transformation and recycling of dissolved organic matter (DOM). Microbial processing of DOM plays a crucial role in reef production, nutrient exchange, and organismal interactions, which are fundamental to the characteristics of coral reefs such as high productivity, balanced metabolism, biodiversity, nutrient retention, and structural complexity. The review summarizes the composition of microbes and DOM in reefs and explores the spatial and temporal dynamics of biogeochemical processes carried out by microorganisms in various reef habitats.
ANNUAL REVIEW OF MARINE SCIENCE
(2023)
Article
Environmental Sciences
Yanwen Huang, Yao Du, Teng Ma, Yamin Deng, Yanqiu Tao, Yu Xu, Zhichao Leng
Summary: High levels of ammonium in groundwater can pose a potential threat to drinking water security and ecosystem health. This study investigated the role of dissolved organic matter (DOM) in mobilizing natural ammonium in groundwater, revealing that groundwater with higher ammonium levels had DOM characterized by larger molecular weight in a more reductive environment, while groundwater with lower ammonium levels had DOM with smaller molecular weight in a more oxidative condition.
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
(2021)
Article
Environmental Sciences
Veronica van der Schyff, Marinus du Preez, Karin Blom, Nee Sun Choong Kwet Yive, Jana Klanova, Petra Pribylova, Ondrej Audy, Jakub Martinik, Hindrik Bouwman
Summary: Persistent halogenated compounds were found in coral reef biota from tropical islands in the western Indian Ocean, including traditional organic pollutants and new compounds. Different species of corals and fish showed varying concentrations and patterns of PHCs, indicating the need for targeted sampling in future surveys. Agalega and St. Brandon's Atoll can serve as monitoring sites for changes in pollutant concentrations due to their remoteness.
Article
Geosciences, Multidisciplinary
Nikita Kaushal, Nivedita Sanwlani, Jani T. I. Tanzil, Nagur Cherukuru, Syamil Sahar, Moritz Mueller, Aazani Mujahid, Jen N. Lee, Nathalie F. Goodkin, Patrick Martin
Summary: Terrigenous dissolved organic matter (tDOM) carried by rivers is an important carbon flux to the coastal ocean, rich in light-absorbent chromophoric dissolved organic matter (CDOM). Luminescence green-to-blue (G/B) ratios in coral cores correlate strongly with remote sensing-derived CDOM absorption, indicating control by rainfall and solar radiation.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Angela Hansen, Tamara Kraus, Matthew Landon, Peter Mcmahon
Summary: This study analyzed dissolved organic carbon concentration and optical spectroscopic techniques (absorbance and fluorescence) of oil-field water and groundwater samples in southern California. The results showed significantly higher DOC concentrations in oil-field water compared to native groundwater samples. Multivariate statistical analysis identified 10 optical properties that were significant in distinguishing water categories. Principal component analysis demonstrated the ability to successfully differentiate oil-field water samples from native groundwater mixed with oil-field water.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Chao Wang, Xuanyu Hu, Yilin Liu, Guangzhe Jin
Summary: Groundwater discharge and river runoff are important pathways for allochthonous dissolved organic matter (DOM) to enter the South China Sea. The source, composition, and efflux of DOM from these sources remains poorly understood. This study conducted analysis along the coast of western Guangdong and found that groundwater DOM mainly originates from microbial activities, while river water DOM has a considerable contribution from terrestrial soil. The findings emphasize the importance of considering groundwater discharge and river runoff in coastal carbon budgets.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Environmental Sciences
Zhou Liang, Robert T. Letscher, Angela N. Knapp
Summary: Surface ocean bulk and semi-labile dissolved organic matter (DOM) stoichiometry vary across ocean regions with global means of 387:26:1 and 179:20:1, respectively. Surface ocean DOC:DOP and DON:DOP concentration ratios are more variable than DOC:DON concentration ratios. Surface ocean gradients in P-depleted DOM stoichiometries in the Pacific and Atlantic basins reflect variable nutrient stress.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Environmental Sciences
Linda Wegley Kelly, Craig E. Nelson, Lihini I. . Aluwihare, Milou G. I. Arts, Pieter C. Dorrestein, Irina Koester, Shayle B. Matsuda, Daniel Petras, Zachary A. Quinlan, Andreas F. Haas
Summary: Metabolomics is a rapidly advancing field that utilizes powerful analytical tools and bioinformatic methods to reveal the diversity and activity of chemical compounds within organisms. By applying metabolomics, it is possible to gain insights into the chemical processes in coastal ecosystems, including metabolite exchange between plants, animals, and microbes, as well as interactions among coral reefs and other organisms.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Environmental Sciences
Kai Xiao, Peng Zhang, Isaac R. Santos, Jun-Jian Wang, Zhenyang Li, Xuejing Wang, Ying-Hui Wang, Meiqing Lu, Licong Zhang, Hailong Li
Summary: Dissolved organic matter (DOM) in highly productive intertidal mangroves plays a significant role as a carbon and nutrient source in the coastal ocean. The influence of groundwater flow on DOM properties and fluxes remains poorly understood. This study highlights the importance of tidal hydrology in controlling groundwater DOM characteristics.
WATER RESOURCES RESEARCH
(2023)
Article
Environmental Sciences
Matthew S. Mills, Tom Schils, Andrew D. Olds, Javier X. Leon
Summary: The complexity of tropical reef habitats affects the organisms residing in these ecosystems. This study used structure-from-motion photogrammetry to quantify the structural complexity of reefs in Guam and found correlations between terrain complexity, benthic community diversity, and coral cover. The study provides insights into Guam's reef complexity and its importance for future assessments.
Article
Engineering, Civil
Yanqiu Tao, Yao Du, Yamin Deng, Teng Ma, Yanxin Wang
Summary: This study reveals that phosphorus-containing dissolved organic matter (DOM) is an important factor controlling groundwater phosphorus enrichment. Through the degradation of DOM, an accumulation and retention process of phosphorus is observed at the molecular level, eventually becoming the predominant phosphorus pool in groundwater.
JOURNAL OF HYDROLOGY
(2023)
Article
Environmental Sciences
Jacqueline V. Alva Garcia, Shannon G. Klein, Taiba Alamoudi, Silvia Arossa, Anieka J. Parry, Alexandra Steckbauer, Carlos M. Duarte
Summary: This study assessed the hypoxic thresholds of two Red Sea coral species and found that longer-term hypoxic events can induce coral bleaching, but the effects vary depending on the extent of O-2 reduction and are likely species-specific. The commonly defined hypoxic O-2 levels do not adequately capture the thresholds reported here.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Rachel R. R. Carlson, Jiwei Li, Larry B. B. Crowder, Gregory P. P. Asner
Summary: Turbidity from land-based runoff can have both negative and positive effects on coral bleaching during ocean heatwaves. This study used high-resolution satellite data to examine the relationship between turbidity and coral bleaching severity in Hawaii. The results showed that the effect of turbidity on bleaching severity weakened at higher temperatures, but still had a slightly negative impact in urban settings. Additionally, interactions between temperature and local variables like turbidity and wave energy were found to be the most significant drivers of bleaching severity.
FRONTIERS IN MARINE SCIENCE
(2022)
Review
Environmental Sciences
Adeleh Aftabtalab, Joerg Rinklebe, Sabry M. Shaheen, Nabeel Khan Niazi, Eduardo Moreno-Jimenez, Joerg Schaller, Klaus-Holger Knorr
Summary: High concentrations of arsenic in groundwater are primarily influenced by arsenic-rich sediments underground. Various processes drive the mobilization of arsenic in aquatic ecosystems, with dissolved arsenic exhibiting high affinity for dissolved organic matter. Understanding the complex interactions and biogeochemical cycling of arsenic, dissolved organic matter, and iron oxides is essential for preventing arsenic contamination spread in aquatic resources.
Article
Environmental Sciences
Peng Wu, Teng Wang, Yong Liu, Chunhou Li, Yayuan Xiao, Shannan Xu, Tingting Han, Lin Lin, Qiumei Quan
Summary: Herbivorous fishes play an important role in preventing the overabundance of macroalgae on coral reefs. Through microscopy, genetic sequencing, and stable isotope analysis, we investigated the feeding behaviors and consumption patterns of eight herbivorous fish species in the Xisha Islands. Among them, Kyphosus vaigiensis, Naso unicornis, and Siganus argenteus demonstrated high potential for macroalgal consumption and should receive priority protection.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Biodiversity Conservation
Shayle B. Matsuda, Leela J. Chakravarti, Ross Cunning, Ariana S. Huffmyer, Craig E. Nelson, Ruth D. Gates, Madeleine J. H. van Oppen
Summary: This study examined the ability of horizontally transmitting coral larvae to establish symbioses with Symbiodiniaceae species from four genera with varying thermal thresholds. Results showed that Gerakladium outcompeted Durusdinium at high temperatures, while Fugacium performed best at 27 and 30 degrees Celsius.
GLOBAL CHANGE BIOLOGY
(2022)
Article
Environmental Sciences
Jessica A. Bullington, Abigail R. Golder, Grieg F. Steward, Margaret A. McManus, Anna B. Neuheimer, Brian T. Glazer, Olivia D. Nigro, Craig E. Nelson
Summary: The south shore of O`ahu, Hawaii, which is one of the most popular coastal tourism areas in the United States, has a high incidence of recreational waterborne disease. Researchers developed a statistical model to predict the dynamics of pathogenic bacterium Vibrio vulnificus in the estuarine Ala Wai Canal in Honolulu. The model utilized environmental measurements and showed that factors such as rainfall, air temperature, water temperature, nitrate plus nitrite, and dissolved organic matter had significant influence on V. vulnificus concentration. Real-time predictions of V. vulnificus concentration can be made using this model applied to water quality measurements.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Limnology
Henrietta Dulai, Celia M. Smith, Daniel W. Amato, Veronica Gibson, Leah L. Bremer
Summary: Coastal groundwater-dependent ecosystems benefit from lowered salinity and nutrient-rich submarine groundwater discharge (SGD). However, human alterations of groundwater resources and climate change-driven shifts have led to changes in the magnitude and composition of SGD. This paper discusses the adaptation of native macroalgae to nutrient and salinity gradients in SGD, as well as the competition from invasive algae near SGD due to nutrient pollution. It highlights the importance of re-evaluating land and water use practices, modifying groundwater sustainable yields, and improving wastewater infrastructure to minimize SGD reductions and maintain optimal nitrogen inputs amidst global sea level rise and reductions in groundwater recharge.
LIMNOLOGY AND OCEANOGRAPHY LETTERS
(2023)
Review
Geochemistry & Geophysics
Craig E. Nelson, Linda Wegley Kelly, Andreas F. Haas
Summary: To survive in nutrient-poor waters, coral reefs depend on efficient retention and recycling of materials. This review focuses on microbial processes that contribute to the persistence and stability of coral reefs, particularly the transformation and recycling of dissolved organic matter (DOM). Microbial processing of DOM plays a crucial role in reef production, nutrient exchange, and organismal interactions, which are fundamental to the characteristics of coral reefs such as high productivity, balanced metabolism, biodiversity, nutrient retention, and structural complexity. The review summarizes the composition of microbes and DOM in reefs and explores the spatial and temporal dynamics of biogeochemical processes carried out by microorganisms in various reef habitats.
ANNUAL REVIEW OF MARINE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Kelly Truax, Henrietta Dulai, Anupam Misra, Wendy Kuhne, Peter Fuleky
Summary: This study demonstrates the application of real-time, non-destructive laser-induced fluorescence (LIF) technique in detecting metal contamination in moss. By comparing the pixel densities of color channels in treated and untreated samples, it shows the potential of LIF for remote monitoring of copper accumulation in moss at mu mol/cm(2) levels.
APPLIED SCIENCES-BASEL
(2022)
Editorial Material
Ecology
Daniel M. Buonaiuto, Megan J. Donahue, Elizabeth M. Wolkovich
Summary: Temperature and light cues interact to control biological processes, but the experimental coupling of photoperiod and thermoperiod introduces unmeasured covariation, leading to biases in statistical inference regarding the effects of these cues.
FUNCTIONAL ECOLOGY
(2023)
Article
Environmental Sciences
Devon K. Aguiar, Tracy N. Wiegner, Steven L. Colbert, John Burns, Leilani Abaya, James Beets, Courtney Couch, Julia Stewart, Jazmine Panelo, Kristina Remple, Craig Nelson
Summary: Sewage pollution from on-site sewage disposal systems and injection wells is impacting coral reefs worldwide. Our study documented the presence and impact of sewage on South Kohala's coral reefs, on Hawai'i Island, through various measurements and surveys. Multiple indicators and studying water motion were necessary to assess sewage pollution and its environmental drivers. The methods used in this study can be utilized by natural resource managers to identify and mitigate anthropogenic stressors to coral reefs.
MARINE POLLUTION BULLETIN
(2023)
Article
Environmental Sciences
Tristan McKenzie, Henrietta Dulai, Jonghyun Lee, Natasha T. Dimova, Isaac R. Santos, Bo Zhang, William Burnett
Summary: This study utilizes deep learning to predict radon concentrations in coastal waters impacted by submarine groundwater discharge. By training two deep learning models, it is possible to predict observed radon concentrations using readily available input parameters, offering an opportunity to obtain radon data in regions with limited data availability.
WATER RESOURCES RESEARCH
(2023)
Article
Environmental Sciences
Adam S. Candy, Shannara K. Taylor K. Parkins, Fleur C. Van Duyl, Benjamin Mueller, Milou G. I. Arts, Will Barnes, Marie Carstensen, Yun J. H. Scholten, Yusuf C. El-Khaled, Christian Wild, Linda Wegley Kelly, Craig E. Nelson, Stuart A. Sandin, Mark J. A. Vermeij, Forest L. Rohwer, Cristian Picioreanu, Paolo Stocchi, Andreas F. Haas
Summary: One mechanism that gives fleshy algae a competitive edge over corals during reef degradation is the occurrence of algal-induced and microbially-mediated hypoxia, which is typically less than 69.5 mu mol oxygen L-1. Algae are more tolerant of low oxygen conditions and may outcompete corals weakened by hypoxia. The extent of local hypoxic zones in highly turbulent aquatic environments, continuously flushed by currents and wave surge, remains a question unanswered.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Environmental Sciences
Kariem Abdulnabi Ghazal, Olkeba Tolessa Leta, Henrietta Dulai
Summary: The integrated hydrological model is utilized to understand the temporal distribution of fresh groundwater discharge and its impact on coastal areas. The coastal regions of Hawaii play a vital role in the economy and ecology of the state. The study focuses on evaluating the fresh submarine groundwater discharge at the Heeia shoreline using the integrated hydrological modeling technique, taking into account various factors such as climate change and sea level rise.
BLUE-GREEN SYSTEMS
(2023)
Article
Environmental Sciences
B. K. Okuhata, J. M. S. Delevaux, A. Richards Dona, C. M. Smith, V. L. Gibson, H. Dulai, A. I. El-Kadi, K. Stamoulis, K. M. Burnett, C. A. Wada, L. L. Bremer
Summary: Groundwater dependent ecosystems (GDEs) are crucial for sustainable groundwater management but are threatened by multiple environmental changes. This study uses a land-sea modeling framework to assess the impact of climate and land use change on submarine groundwater discharge (SGD) and habitat suitability for two macroalgae in nearshore GDEs in Hawai'i. The results show that protecting native forests can partially mitigate the decline in habitat suitability caused by climate and land use change, while reductions in SGD may favor the growth of an invasive macroalgae. This study highlights the importance of considering multiple drivers of environmental change on GDEs and informs management actions.
WATER RESOURCES RESEARCH
(2023)
Article
Plant Sciences
Kelly Truax, Henrietta Dulai, Anupam Misra, Wendy Kuhne, Peter Fuleky, Celia Smith, Milton Garces
Summary: Researchers have successfully identified different metals and environmental stressors using laser-induced fluorescence (LIF) imaging analysis of moss. The analysis of RGB values in the images allows for the detection of contaminated samples, distinguishing them from photoperiod and other environmental factors.
Article
Ecology
Sheree J. Watson, Cedric Arisdakessian, Maria Petelo, KekuModified Letter Turned Commaiapoiula Keliipuleole, Diamond K. Tachera, Brytne K. Okuhata, Henrietta Dulai, Kiana L. Frank
Summary: This study investigates the influence of geology and land management on the geochemistry, microbial diversity, and metabolic functions of groundwater ecosystems in Hawai'i. The findings suggest that sulfate levels are higher in the northwest volcanic rift zone, and nitrogen levels are correlated with the density of on-site sewage disposal systems. The presence of a putative S-oxidizer (Acinetobacter) suggests the potential for microbial-driven bioremediation of volcanic groundwater.
ISME COMMUNICATIONS
(2023)
Article
Biology
Mary K. Donovan, Chelsie W. W. Counsell, Megan J. Donahue, Joey Lecky, Laura Gajdzik, Stacia D. Marcoux, Russell Sparks, Christopher Teague
Summary: Herbivore management is crucial for resilience-based coral reef conservation. This study analyzed data from multiple monitoring programs in Hawai'i and found that herbivore biomass varied significantly throughout the region. Both human and biophysical drivers explained the variation in herbivore biomass, and fishing and land-based pollution had negative effects on biomass. The study also revealed a strong link between herbivore biomass and benthic condition.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2023)
Article
Microbiology
Wesley J. Sparagon, Emily C. Gentry, Jeremiah J. Minich, Lisa Vollbrecht, Lieve M. L. Laurens, Eric E. Allen, Neil A. Sims, Pieter C. Dorrestein, Linda Wegley Kelly, Craig E. Nelson
Summary: This study integrates microbial and chemical data to reveal the changes in gut microbial communities and metabolomes. The results show that different gut sections have distinct microenvironments, with the hindgut dominated by anaerobic bacteria. The study also suggests that the relationship between microbes and metabolites is associated with bile acids, small peptides, and phospholipids in the gut.
Article
Chemistry, Multidisciplinary
Morgane Leon, Pieter van Beek, Virginie Sanial, Marc Souhaut, Paul Henderson, Matthew A. Charette
Summary: The analysis of radium and actinium isotopes in seawater requires the collection of large volumes of water and the use of high sensitivity instruments. To concentrate these isotopes, filters impregnated with MnO2 are typically used. However, the extraction efficiency of these filters for the target isotopes needs to be determined.