Spatial variation in marine oxygen isotope ratios (δ (18)O) resulting from differential evaporation rates and precipitation inputs is potentially useful for characterizing marine mammal distributions and tracking movements across δ (18)O gradients. Dentine hydroxyapatite contains carbonate and phosphate that precipitate in oxygen isotopic equilibrium with body water, which in odontocetes closely tracks the isotopic composition of ambient water. To test whether dentine oxygen isotope composition reliably records that of ambient water and can therefore serve as a proxy for odontocete distribution and movement patterns, we measured δ (18)O values of dentine structural carbonate (δ (18) OSC) and phosphate (δ (18) OP) of seven odontocete species (n = 55 individuals) from regional marine water bodies spanning a surface water δ (18)O range of several per mil. Mean dentine δ (18) OSC (range +21.2 to +25.5‰ VSMOW) and δ (18) OP (+16.7 to +20.3‰) values were strongly correlated with marine surface water δ (18)O values, with lower dentine δ (18) OSC and δ (18) OP values in high-latitude regions (Arctic and Eastern North Pacific) and higher values in the Gulf of California, Gulf of Mexico, and Mediterranean Sea. Correlations between dentine δ (18) OSC and δ (18) OP values with marine surface water δ (18)O values indicate that sequential δ (18)O measurements along dentine, which grows incrementally and archives intra- and interannual isotopic composition over the lifetime of the animal, would be useful for characterizing residency within and movements among water bodies with strong δ (18)O gradients, particularly between polar and lower latitudes, or between oceans and marginal basins.
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http://dx.doi.org/10.1002/ece3.2238 | DOI Listing |
Commun Earth Environ
November 2024
School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100010 China.
Chem Sci
November 2024
State Key Laboratory Cultivation Base for TCM Quality and Efficacy, School of Pharmacy, Nanjing University of Chinese Medicine Nanjing 210023 China
Xanthone-based polyketides with complex molecular frameworks and potent bioactivities distribute and function in different biological kingdoms, yet their biosynthesis remains under-investigated. In particular, nothing is known regarding how to switch between the C-C (C-selective) and C-C bond (C-selective) cleavages of anthraquinone intermediates involved in biosynthesizing strikingly different frameworks of xanthones and their siblings. Enabled by our characterization of antiosteoporotic brunneoxanthones, a subfamily of polyketides from FB-2, we present herein the brunneoxanthone biosynthetic gene cluster and the C-selective cleavage of anthraquinone (chrysophanol) hydroquinone leading ultimately to the bioactive brunneoxanthones under the catalysis of BruN (an undescribed atypical non-heme iron dioxygenase) in collaboration with BruM as a new oxidoreductase that reduces the anthraquinone into its hydroquinone using NADPH as a cofactor.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2024
Institute of Geosciences, University of Bremen, 28359, Bremen, Germany.
The eastern Niger Delta region in Nigeria is a hotspot for reactive nitrogen pollution due to extensive animal husbandry, pit latrine usage, and agricultural practices. Despite the high level of human activity, the sources and processes affecting nitrogen in groundwater remain understudied. Groundwater nitrate (NO) concentrations are highly variable, with some areas recording values well above the safe drinking water threshold of 50 mg/L.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
November 2024
Department of Data Science and Visualization, Faculty of Informatics, University of Debrecen, Debrecen, H‑4028, Hungary.
Over the last decades, as a consequence of wastewater discharges and other anthropogenic sources, severe nitrate (NO) pollution has developed in municipal environment causing global concern. Thus, eliminating the potential sources of pollution is one of the major challenges of the twenty-first century, whereby sanitation services are essential for ensuring public health and environmental protection. In the present study, long-term monitoring (2011-2022) of shallow groundwater NO contamination in municipal environment was carried following the construction of the sewerage network (2014) in the light of the pre-sewerage situation.
View Article and Find Full Text PDFSci Total Environ
December 2024
National Institute of Fundamental Studies, Hanthana Road, Kandy 20000, Sri Lanka. Electronic address:
Sri Lanka, a tropical island, confronts climate-driven water scarcity and is of great concern to building climate-resilient water management to achieve UN SDGs 6 and 13. This study explores the dynamic interaction between surface water (SW) and groundwater (GW) in the dry zone of Sri Lanka, employing a multi-tracer of dual stable isotopes (O and H) and chloride. Two basins, Mahakanadarawa (MK) basin with numerous village tanks and tank cascade systems (VTCSs/TCSs) and Kawudulla (KW) basin serving as a control with a lack of tanks, were selected in this study.
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