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Full-Text Articles in Oceanography
The Vulnerability And Resilience Of Seagrass Ecosystems To Marine Heatwaves In New Zealand: A Remote Sensing Analysis Of Seascape Metrics Using Planetscope Imagery, Ken Joseph E. Clemente, Mads S. Thomsen, Richard C. Zimmerman
The Vulnerability And Resilience Of Seagrass Ecosystems To Marine Heatwaves In New Zealand: A Remote Sensing Analysis Of Seascape Metrics Using Planetscope Imagery, Ken Joseph E. Clemente, Mads S. Thomsen, Richard C. Zimmerman
OES Faculty Publications
Seagrasses are foundation species that provide ecosystem functions and services, including increased biodiversity, sediment retention, carbon sequestration, and fish nursery habitat. However, anthropogenic stressors that reduce water quality, impose large-scale climate changes, and amplify weather patterns, such as marine heatwaves, are altering seagrass meadow configurations. Quantifying large-scale trends in seagrass distributions will help evaluate the impacts of climate drivers on their functions and services. Here, we quantified spatiotemporal dynamics in abundances and configurations of intertidal and shallow subtidal seagrass (Zostera muelleri) meadows in 20 New Zealand (NZ) estuaries that span a 5-year period (mid/late 2016–early 2022) just before, …
Providing A Framework For Seagrass Mapping In United States Coastal Ecosystems Using High Spatial Resolution Satellite Imagery, Megan M. Coffer, David D. Graybill, Peter J. Whitman, Blake A. Schaeffer, Wilson B. Salls, Richard C. Zimmerman, Victoria Hill, Marie Cindy Lebrasse, Jiang Li, Darryl J. Keith, James Kaldy, Phil Colarusso, Gary Raulerson, David Ward, W. Judson Kenworthy
Providing A Framework For Seagrass Mapping In United States Coastal Ecosystems Using High Spatial Resolution Satellite Imagery, Megan M. Coffer, David D. Graybill, Peter J. Whitman, Blake A. Schaeffer, Wilson B. Salls, Richard C. Zimmerman, Victoria Hill, Marie Cindy Lebrasse, Jiang Li, Darryl J. Keith, James Kaldy, Phil Colarusso, Gary Raulerson, David Ward, W. Judson Kenworthy
OES Faculty Publications
Seagrasses have been widely recognized for their ecosystem services, but traditional seagrass monitoring approaches emphasizing ground and aerial observations are costly, time-consuming, and lack standardization across datasets. This study leveraged satellite imagery from Maxar's WorldView-2 and WorldView-3 high spatial resolution, commercial satellite platforms to provide a consistent classification approach for monitoring seagrass at eleven study areas across the continental United States, representing geographically, ecologically, and climatically diverse regions. A single satellite image was selected at each of the eleven study areas to correspond temporally to reference data representing seagrass coverage and was classified into four general classes: land, seagrass, no …
Impact Of Atmospheric Correction On Classification And Quantification Of Seagrass Density From Worldview-2 Imagery, Victoria J. Hill, Richard C. Zimmerman, Paul Bissett, David Kohler, Blake Schaeffer, Megan Coffer, Jiang Li, Kazi Aminul Islam
Impact Of Atmospheric Correction On Classification And Quantification Of Seagrass Density From Worldview-2 Imagery, Victoria J. Hill, Richard C. Zimmerman, Paul Bissett, David Kohler, Blake Schaeffer, Megan Coffer, Jiang Li, Kazi Aminul Islam
OES Faculty Publications
Mapping the seagrass distribution and density in the underwater landscape can improve global Blue Carbon estimates. However, atmospheric absorption and scattering introduce errors in space-based sensors’ retrieval of sea surface reflectance, affecting seagrass presence, density, and above-ground carbon (AGCseagrass) estimates. This study assessed atmospheric correction’s impact on mapping seagrass using WorldView-2 satellite imagery from Saint Joseph Bay, Saint George Sound, and Keaton Beach in Florida, USA. Coincident in situ measurements of water-leaving radiance (Lw), optical properties, and seagrass leaf area index (LAI) were collected. Seagrass classification and the retrieval of LAI were compared after empirical line …
Photorespiration In Eelgrass (Zostera Marina L.): A Photoprotection Mechanism For Survival In A Co₂-Limited World, Billur Celebi-Ergin, Richard C. Zimmerman, Victoria J. Hill
Photorespiration In Eelgrass (Zostera Marina L.): A Photoprotection Mechanism For Survival In A Co₂-Limited World, Billur Celebi-Ergin, Richard C. Zimmerman, Victoria J. Hill
OES Faculty Publications
Photorespiration, commonly viewed as a loss in photosynthetic productivity of C3 plants, is expected to decline with increasing atmospheric CO2, even though photorespiration plays an important role in the oxidative stress responses. This study aimed to quantify the role of photorespiration and alternative photoprotection mechanisms in Zostera marina L. (eelgrass), a carbon-limited marine C3 plant, in response to ocean acidification. Plants were grown in controlled outdoor aquaria at different [CO2]aq ranging from ~55 (ambient) to ~2121 μM for 13 months and compared for differences in leaf photochemistry by simultaneous measurements of O2 flux and …
Temporal Stability Of Seagrass Extent, Leaf Area, And Carbon Storage In St. Joseph Bay, Florida: A Semi-Automated Remote Sensing Analysis, Marie Cindy Lebrasse, Blake A. Schaeffer, Megan M. Coffer, Peter J. Whitman, Richard C. Zimmerman, Victoria J. Hill, Kazi A. Islam, Jiang Li, Christopher L. Osburn
Temporal Stability Of Seagrass Extent, Leaf Area, And Carbon Storage In St. Joseph Bay, Florida: A Semi-Automated Remote Sensing Analysis, Marie Cindy Lebrasse, Blake A. Schaeffer, Megan M. Coffer, Peter J. Whitman, Richard C. Zimmerman, Victoria J. Hill, Kazi A. Islam, Jiang Li, Christopher L. Osburn
OES Faculty Publications
Seagrasses are globally recognized for their contribution to blue carbon sequestration. However, accurate quantification of their carbon storage capacity remains uncertain due, in part, to an incomplete inventory of global seagrass extent and assessment of its temporal variability. Furthermore, seagrasses are undergoing significant decline globally, which highlights the urgent need to develop change detection techniques applicable to both the scale of loss and the spatial complexity of coastal environments. This study applied a deep learning algorithm to a 30-year time series of Landsat 5 through 8 imagery to quantify seagrass extent, leaf area index (LAI), and belowground organic carbon (BGC) …
Simulated Response Of St. Joseph Bay, Florida, Seagrass Meadows And Their Belowground Carbon To Anthropogenic And Climate Impacts, Marie Cindy Lebrasse, Blake A. Schaeffer, Richard C. Zimmerman, Victoria J. Hill, Megan M. Coffer, Peter J. Whitman, Wilson B. Salls, David D. Graybill, Christopher L. Osburn
Simulated Response Of St. Joseph Bay, Florida, Seagrass Meadows And Their Belowground Carbon To Anthropogenic And Climate Impacts, Marie Cindy Lebrasse, Blake A. Schaeffer, Richard C. Zimmerman, Victoria J. Hill, Megan M. Coffer, Peter J. Whitman, Wilson B. Salls, David D. Graybill, Christopher L. Osburn
OES Faculty Publications
Seagrass meadows are degraded globally and continue to decline in areal extent due to human pressures and climate change. This study used the bio-optical model GrassLight to explore the impact of climate change and anthropogenic stressors on seagrass extent, leaf area index (LAI) and belowground organic carbon (BGC) in St. Joseph Bay, Florida, using water quality data and remotely-sensed sea surface temperature (SST) from 2002 to 2020. Model predictions were compared with satellite-derived measurements of seagrass extent and shoot density from the Landsat images for the same period. The GrassLight-derived area of potential seagrass habitat ranged from 36.2 km2 …
Dynamics Of Carbon Allocation In A Deep-Water Population Of The Deciduous Kelp Pleurophycus Gardeneri (Laminariales), Clare M. Dominik, Richard C. Zimmerman
Dynamics Of Carbon Allocation In A Deep-Water Population Of The Deciduous Kelp Pleurophycus Gardeneri (Laminariales), Clare M. Dominik, Richard C. Zimmerman
OES Faculty Publications
Pleurophycus gardneri (Laminariales) is common in the low intertidal of the Northeast Pacific, but dominates many deep (30 to 40 m) rocky reefs in central California. Seasonal dynamics of productivity and resource allocation of a deep-water population of this deciduous, stipitate kelp were studied to understand how blade abscission affects the annual carbon budget. Patterns of growth, metabolism, and carbon storage and mobilization were measured monthly for 1 yr relative to in situ light and temperature, and used to model the annual carbon budget. The resulting carbon budget was used to determine if blade abscission effectively reduced respiratory demand during …
Chemistry Of Surface Waters: Distinguishing Fine-Scale Differences In Sea Grass Habitats Of Chesapeake Bay, Emmanis Dorval, Cynthia M. Jones
Chemistry Of Surface Waters: Distinguishing Fine-Scale Differences In Sea Grass Habitats Of Chesapeake Bay, Emmanis Dorval, Cynthia M. Jones
OES Faculty Publications
We tested the hypothesis that the physical and chemical processes acting in sea grass habitats of the lower Chesapeake Bay are spatially structured and that dissolved elemental chemistry of sea grass-habitat surface waters have their own unique identity. We sampled surface waters from July to September 2001 in five sea grass habitats of the lower bay: Potomac, Rappahannock, York, Island (Tangier-Bloodsworth), and Eastern Shore. Dissolved Mg, Mn, Sr, and Ba concentrations were measured by sector field inductively coupled plasma-mass spectrometry. As expected, Mg, Sr, and Ba exhibited conservative behavior, but Mn exhibited nonconservative behavior along the salinity gradient. Spatial differences …
Impact Of Sea Grass Density On Carbonate Dissolution In Bahamian Sediments, David J. Burdige, Richard C. Zimmerman
Impact Of Sea Grass Density On Carbonate Dissolution In Bahamian Sediments, David J. Burdige, Richard C. Zimmerman
OES Faculty Publications
Carbonate dissolution has been widely observed in shallow water tropical sediments. However, sediment budgets C have generally not been closed with respect to the amount of acid required to produce the observed carbonate dissolution. Recently it has been suggested that enhanced oxygen transport into sediments through the roots and rhizomes of sea grasses might play a role in resolving this mass balance problem. We conducted studies of sea grass-carbonate sediment interactions around Lee Stocking Island, Exuma Islands, Bahamas to further examine this problem. Our studies showed that alkalinity, total dissolved inorganic carbon (ΣCO2) and Ca2+ increased with …
Top-Down Impact Through A Bottom-Up Mechanism. In Situ Effects Of Limpet Grazing On Growth, Light Requirements And Survival Of The Eelgrass Zostera Marina, Richard C. Zimmerman, Diana L. Steller, Donald G. Kohrs, Randall S. Alberte
Top-Down Impact Through A Bottom-Up Mechanism. In Situ Effects Of Limpet Grazing On Growth, Light Requirements And Survival Of The Eelgrass Zostera Marina, Richard C. Zimmerman, Diana L. Steller, Donald G. Kohrs, Randall S. Alberte
OES Faculty Publications
Temporal changes in abundance, size, productivity, resource allocation and light requirements of a subtidal eelgrass (Zostera marina L.) population were followed for 2 yr after the September 1993 appearance of a previously rare oval form of the commensal limpet Tectura depicta (Berry) in Monterey Bay, California, USA, By exclusively targeting the epidermis, limpet grazing impaired photosynthetic performance but left respiratory demand, meristematic growth and more than 90 % of the leaf biomass intact, The resulting low P:R ratios of grazed plants raised the light requirements for the maintenance of positive carbon balance almost 2-fold relative to healthy ungrazed plants …
Resource Allocation And Sucrose Mobilization In Light Limited Eelgrass Zostera Marina, Teresa Alcoverro, Richard C. Zimmerman, Donald G. Kohrs, Randall S. Alberte
Resource Allocation And Sucrose Mobilization In Light Limited Eelgrass Zostera Marina, Teresa Alcoverro, Richard C. Zimmerman, Donald G. Kohrs, Randall S. Alberte
OES Faculty Publications
This study evaluated the ability of Zostera marina L. (eelgrass) to balance the daily photosynthetic deficit by mobilization of carbon reserves stored in below-ground tissues during a period of extreme winter light limitation. A quantitative understanding of the mobilization process and its limitations is essential to the development of robust models predicting minimum light levels required to maintain healthy seagrass populations. Plants were grown in running seawater tanks under 2 light regimes. One treatment was provided with 2 h irradiance-saturated photosynthesis (Hsat) to produce severe Light Limitation, while control plants were grown under 7 h Hsat, …
Effect Of Light/Dark Transition On Carbon Translocation In Eelgrass Zostera Marina Seedlings, Richard C. Zimmerman, Randall S. Alberte
Effect Of Light/Dark Transition On Carbon Translocation In Eelgrass Zostera Marina Seedlings, Richard C. Zimmerman, Randall S. Alberte
OES Faculty Publications
Carbon translocation in the marine macrophyte Zostera marina L. (eelgrass) was investigated to elucidate the impact of light/dark transitions on sucrose partitioning between roots and shoots. After exposure of leaves to C-14-bicarbonate, the level of C-14-labelled photoassimilates increased monotonically in both leaves and fully aerobic roots of plants maintained in the light. Accumulation of C-14 in roots and leaves ceased abruptly when plants were transferred to darkness that induced root anaerobiosis even though C-14 levels remained high in the dark-exposed leaves. Thus, translocation of C-14 photoassimilates from shoots to roots was inhibited when roots became anoxic. Anoxia induced by light …