scholarly journals Lagoon Biogeochemical Processing is Reflected in Spatial Patterns of Sediment Stable Isotopic Ratios

2020 ◽  
Vol 8 (11) ◽  
pp. 874
Author(s):  
Elizabeth Burke Watson ◽  
Alejandro Hinojosa-Corona ◽  
Johannes R. Krause ◽  
Juan Carlos Herguera ◽  
Julianna McDonnell ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Spatial Patterns ◽  
Nitrogen Isotopes ◽  
Carbon Accumulation ◽  
Isotopic Ratios ◽  
Spatial Gradients ◽  
Seagrass Meadows ◽  
The Pacific ◽  
Stable Isotopic ◽  
Sediment Carbon

The spatial analysis of biota, particulate organic matter, and sediments for stable isotopes of carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) have proved useful for identifying patterns in productivity, nutrient pollution, and relationships between biological and physiochemical variables at the local and global scales. Yet such approaches are rarely applied to studies of lagoon or estuarine metabolism. Focusing on Bahía San Quintín, a heterotrophic seagrass-dominated lagoon on the Pacific coast of Baja California, México, we report on spatial patterns in surficial sediment CNS stable isotopic ratios as tracers of lagoon biogeochemical function. Stable nitrogen isotopes highlighted potential spatial variability in the balance between denitrification and nitrogen-fixation within the lagoon and identified an association between elevated δ15N levels and oyster culture, suggesting that oyster presence may be enhancing N2 production. Spatial patterns in δ34S covaried with sediment particle size, underlining the importance of sediment texture in determining the depth of sub-oxic-anoxic redox zones. Sediment carbon stable isotope ratios highlighted the lack of incorporation of seagrass carbon into seagrass meadow sediments, thus emphasizing the importance of phytoplankton or microphytobenthos for carbon accumulation in seagrass meadows. This report highlights the value of sediment isotopic values in corroborating spatial patterns in estuarine metabolism or macronutrient processing identified from chamber or flux-based studies. Stable isotope mapping can provide a useful addition to assessment of estuarine metabolism, or act as a stand-alone tool for generating hypotheses, identifying the influence of spatial gradients, and/or suggesting prime locations for investigation of microbial abundance or function.

scholarly journals Survey of Nitrogen Isotopes of Lepomis macrochirus (Blue Gill) from Kentucky Lake Reservoir and Ledbetter Creek, Kentucky

2008 ◽  
Vol 7 (2) ◽  
Author(s):  
Rebecca Cripps ◽  
George Kipphut
Keyword(s):  
Food Source ◽  
Nitrogen Isotopes ◽  
Lepomis Macrochirus ◽  
Isotopic Signature ◽  
Trophic Relationships ◽  
Isotopic Ratios ◽  
Stable Isotopic ◽  
Kentucky Lake ◽  
Western Kentucky ◽  
Small Tributary

Previous research has shown stable isotope ratios of nitrogen in fish and other animals may vary depending on their food source. Ecologists have had some success in determining feeding and trophic relationships within an ecosystem using stable isotopic ratios. In this study, nitrogen stable isotopic ratios were measured in populations of Lepomis macrochirus (Blue Gill) in Kentucky Lake Reservoir and in a small tributary, Ledbetter Creek, in western Kentucky. The nitrogen isotopic ratios between these populations were statistically different. Even though fish are able to migrate freely between the two environments, the isotopic results suggest that the Lepomis macrochirus in Ledbetter Creek were spending enough time feeding in that environment to alter their isotopic signature. These results may lead to a better understanding of how Lepomis macrochirus utilize both stream and reservoir environments.

scholarly journals Blue Carbon Stocks and Exchanges Along the Pacific West Coast

2021 ◽  
Author(s):  
Melissa A. Ward ◽  
Tessa M. Hill ◽  
Chelsey Souza ◽  
Tessa Filipczyk ◽  
Aurora M. Ricart ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Carbon Sources ◽  
Carbon Stocks ◽  
Blue Carbon ◽  
Seagrass Meadows ◽  
The Pacific ◽  
Terrestrial Habitats ◽  
Isotope Mixing Models ◽  
Sediment Carbon

Abstract. Salt marshes and seagrass meadows can sequester and store high quantities of organic carbon (OC) in their sediments relative to other marine and terrestrial habitats. Assessing carbon stocks, carbon sources, and the transfer of carbon between habitats within coastal seascapes are each integral in identifying the role of blue carbon habitats in coastal carbon cycling. Here, we quantified carbon stocks, sources, and exchanges in seagrass meadows, salt marshes, and unvegetated sediments in six bays along the Pacific coast of California. The salt marshes studied here contained approximately twice as much OC as did seagrass meadows, 23.51 ± 1.77 kg OC m−3 compared to 11.01 ± 1.18 kg OC m−3, respectively. Both seagrass and salt marsh sediment carbon stocks were higher than previous estimates from this region but lower than global and U.S.-wide averages, respectively. Seagrass-derived carbon was deposited annually into adjacent marshes during fall seagrass senescence. However, isotope mixing models estimate that negligible amounts of this seagrass material were ultimately buried in underlying sediment. Rather, the vast majority of OC in sediment across sites was likely derived from planktonic/benthic diatoms and C3 salt marsh plants.

Genesis of bentonites from Cabo de Gata, Almeria, Spain: a stable isotope study

Clay Minerals ◽  
1983 ◽  
Vol 18 (3) ◽  
pp. 227-238 ◽  
Author(s):  
G. Leone ◽  
E. Reyes ◽  
G. Cortecci ◽  
A. Pochini ◽  
J. Linares
Keyword(s):  
Stable Isotope ◽  
Low Temperature ◽  
Volcanic Rocks ◽  
Isotopic Ratios ◽  
Normal Surface ◽  
Surface Conditions ◽  
Stable Isotopic ◽  
Isotope Study ◽  
Stable Isotope Study

AbstractOxygen (18O/16O) and hydrogen (2H/1H) isotopic ratios were measured on 22 smectite separates from bentonite deposits of the Sierra de Gata and Serrata de Nijar, Almeria, Spain. In addition, 18O/16O and 2H/1H ratios were determined on some waters from springs and wells, and 18O/16O ratios were measured on quartz, plagioclase and biotite samples separated from the bentonites. The smectites displayed two distinct isotopic compositional groups which excluded an origin either by submarine alteration or weathering under normal surface conditions of the associated volcanic rocks. Bentonization processes caused by low-temperature fluids of meteoric origin could account for the stable isotopic contents. Argillization temperatures are estimated at ∼40°C and ∼70°C for the Serrata de Nijar and the Sierra de Gata deposits, respectively.

Inferring spatial patterns of mercury exposure in migratory boreal songbirds: Combining feather mercury and stable isotope (δ2H) measurements

2020 ◽  
pp. 143109
Author(s):  
Yanju Ma ◽  
Keith A. Hobson ◽  
Kevin J. Kardynal ◽  
Christopher G. Guglielmo ◽  
Brian A. Branfireun
Keyword(s):  
Stable Isotope ◽  
Spatial Patterns ◽  
Mercury Exposure

The sediment carbon stocks of intertidal seagrass meadows in Scotland

2021 ◽  
pp. 107442
Author(s):  
Maria Potouroglou ◽  
Danielle Whitlock ◽  
Luna Milatovic ◽  
Gillian MacKinnon ◽  
Hilary Kennedy ◽  
...  
Keyword(s):  
Carbon Stocks ◽  
Seagrass Meadows ◽  
Intertidal Seagrass ◽  
Sediment Carbon

scholarly journals Factors Influencing Carbon Stocks and Accumulation Rates in Eelgrass Meadows Across New England, USA

2020 ◽  
Vol 43 (8) ◽  
pp. 2076-2091 ◽  
Author(s):  
A. B. Novak ◽  
M. C. Pelletier ◽  
P. Colarusso ◽  
J. Simpson ◽  
M. N. Gutierrez ◽  
...  
Keyword(s):  
Grain Size ◽  
New England ◽  
Structural Characteristics ◽  
Sediment Cores ◽  
Carbon Stocks ◽  
Carbon Accumulation ◽  
Accumulation Rates ◽  
Seagrass Meadows ◽  
Terrestrial Habitats ◽  
C And N

Abstract Increasing the protection of coastal vegetated ecosystems has been suggested as one strategy to compensate for increasing carbon dioxide (CO2) in the atmosphere as the capacity of these habitats to sequester and store carbon exceeds that of terrestrial habitats. Seagrasses are a group of foundation species that grow in shallow coastal and estuarine systems and have an exceptional ability to sequester and store large quantities of carbon in biomass and, particularly, in sediments. However, carbon stocks (Corg stocks) and carbon accumulation rates (Corg accumulation) in seagrass meadows are highly variable both spatially and temporally, making it difficult to extrapolate this strategy to areas where information is lacking. In this study, Corg stocks and Corg accumulation were determined at 11 eelgrass meadows across New England, representing a range of eutrophication and exposure conditions. In addition, the environmental factors and structural characteristics of meadows related to variation in Corg stocks were identified. The objectives were accomplished by assessing stable isotopes of δ13C and δ15N as well as %C and %N in plant tissues and sediments, measuring grain size and 210Pb of sediment cores, and through assessing site exposure. Variability in Corg stocks in seagrass meadows is well predicted using commonly measured environmental variables such as grain size distribution. This study allows incorporation of data and insights for the northwest Atlantic, where few studies on carbon sequestration by seagrasses have been conducted.

scholarly journals The isotopic differences and implications for Pacific razor clams along the Washington coast

2019 ◽  
Vol 98 ◽  
pp. 12005
Author(s):  
Yongwen Gao ◽  
Joseph Gilbertson ◽  
Hongyan Zhang
Keyword(s):  
Stable Isotope ◽  
Isotope Analysis ◽  
Survival Rates ◽  
Washington State ◽  
Growth And Survival ◽  
Razor Clam ◽  
The Pacific ◽  
Indian Tribes ◽  
Razor Clams ◽  
Biological Differences

The Pacific razor clam fishery in Washington State has been co-managed by the coastal Indian Tribes and the state, but little is known about the growth and population structure of the clams due to difficulties of tagging and monitoring. Here we report the results of a pilot study using stable isotope ratios (δ13C and δ18O) of razor clam shells collected in two groups (juvenile vs. adult) and from two sites (Kalaloch Beach and Roosevelt Beach) where distinct biological differences in clam growth and survival rates were observed. The δ13C values of razor clam shells ranged from -2.9 to -0.3‰, whereas δ18O values of the same samples ranged from -2.2 to +1.4‰. Between the two sites there were significant differences in δ13C values especially for juvenile clams. The δ18O profiles from two representative shells demonstrated similar patterns of rapid growth as juveniles and seasonal patterns throughout the life span. Profiles of δ13C were sinusoidal but did not show seasonality and signatures of ocean acidification. We concluded that stable isotope analysis of razor clam shells is a potential new tool in shellfish research and management.

Sign in / Sign up

Export Citation Format

Share Document