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Full-Text Articles in Life Sciences
Long-Term Observations Of Pteropod Phenology Along The Western Antarctic Peninsula, Patrica S. Thibodeau, Deborah K. Steinberg, Colleen E. Mcbride, John A. Conroy, Hugh W. Ducklow
Long-Term Observations Of Pteropod Phenology Along The Western Antarctic Peninsula, Patrica S. Thibodeau, Deborah K. Steinberg, Colleen E. Mcbride, John A. Conroy, Hugh W. Ducklow
VIMS Articles
Shifts in phenology – annually occurring life history events – have been observed among many marine organisms due to global warming. We examined if phenological changes in the pteropod (pelagic snail) Limacina helicina antarctica have occurred along the Western Antarctic Peninsula, one of the most intensely warming regions on Earth, which would have important implications for regional food web dynamics. Pteropod shell diameters were analyzed from samples collected in the Palmer Antarctica Long-Term Ecological Research (PAL LTER) program year-round sediment trap from 2004 to 2018. There was considerable interannual variability in the time of appearance of a new pteropod cohort, …
Not All Nitrogen Is Created Equal: Differential Effects Of Nitrate And Ammonium Enrichment In Coastal Wetlands, Jennifer L. Bowen, Anne E. Giblin, Anna E. Murphy, Ashley N. Bulseco, Linda A. Deegan, David S. Johnson, Et Al
Not All Nitrogen Is Created Equal: Differential Effects Of Nitrate And Ammonium Enrichment In Coastal Wetlands, Jennifer L. Bowen, Anne E. Giblin, Anna E. Murphy, Ashley N. Bulseco, Linda A. Deegan, David S. Johnson, Et Al
VIMS Articles
Excess reactive nitrogen (N) flows from agricultural, suburban, and urban systems to coasts, where it causes eutrophication. Coastal wetlands take up some of this N, thereby ameliorating the impacts on nearshore waters. Although the consequences of N on coastal wetlands have been extensively studied, the effect of the specific form of N is not often considered. Both oxidized N forms (nitrate, NO3−) and reduced forms (ammonium, NH4+) can relieve nutrient limitation and increase primary production. However, unlike NH4+, NO3− can also be used as an electron acceptor for microbial respiration. We present results demonstrating that, in …
Estimating Shifts In Phenology And Habitat Use Of Cobia In Chesapeake Bay Under Climate Change, Daniel P. Crear, Brian E. Watkins, Marjorie A.M. Friedrichs, Pierre St-Laurent, Kevin C. Weng
Estimating Shifts In Phenology And Habitat Use Of Cobia In Chesapeake Bay Under Climate Change, Daniel P. Crear, Brian E. Watkins, Marjorie A.M. Friedrichs, Pierre St-Laurent, Kevin C. Weng
VIMS Articles
Cobia (Rachycentron canadum) is a large coastal pelagic fish species that represents an important fishery in many coastal Atlantic states of the U.S. They are heavily fished in Virginia when they migrate into Chesapeake Bay during the summer to spawn and feed. These coastal habitats have been subjected to warming and increased hypoxia which in turn could impact the timing of migration and the habitat suitability of Chesapeake Bay. With conditions expected to worsen, we project current and future habitat suitability of Chesapeake Bay for cobia and predict changes in their arrival and departure times as conditions shift. To do …
Challenges For Restoration Of Coastal Marine Ecosystems In The Anthropocene, Avigdor Abelson, Daniel Reed, Graham J. Edgar, Carter S. Smith, Gary A. Kendrick, R J. Orth, Et Al
Challenges For Restoration Of Coastal Marine Ecosystems In The Anthropocene, Avigdor Abelson, Daniel Reed, Graham J. Edgar, Carter S. Smith, Gary A. Kendrick, R J. Orth, Et Al
VIMS Articles
Coastal marine ecosystems provide critical goods and services to humanity but many are experiencing rapid degradation. The need for effective restoration tools capable of promoting large-scale recovery of coastal ecosystems in the face of intensifying climatic stress has never been greater. We identify four major challenges for more effective implementation of coastal marine ecosystem restoration (MER): (1) development of effective, scalable restoration methods, (2) incorporation of innovative tools that promote climate adaptation, (3) integration of social and ecological restoration priorities, and (4) promotion of the perception and use of coastal MER as a scientifically credible management approach. Tackling these challenges …
Spatial Variations Of Phytoplankton Biomass Controlled By River Plume Dynamics Over The Lower Changjiang Estuary And Adjacent Shelf Based On High-Resolution Observations, Zhaoru Zhang, Meng Zhou, Et Al, Walker O. Smith Jr.
Spatial Variations Of Phytoplankton Biomass Controlled By River Plume Dynamics Over The Lower Changjiang Estuary And Adjacent Shelf Based On High-Resolution Observations, Zhaoru Zhang, Meng Zhou, Et Al, Walker O. Smith Jr.
VIMS Articles
Phytoplankton biomass in estuarine and continental shelf regions are regulated and modified by physical processes, but these interactions have mostly been investigated at a scale of tens of kilometers, and the role of meso- to sub-mesoscale dynamical processes of freshwater plumes in regulating the spatial and temporal variations of algal biomass is largely unknown. To assess the importance of features at these scales, high-resolution (horizontal spacing < 1 km) cross-sectional profiles of hydrographic and biogeochemical variables were collected in the lower Changjiang Estuary and adjacent continental shelf with a towed, undulating vehicle equipped with sensors measuring fluorescence, turbidity and irradiance. Discrete stations were also occupied to allow for the characterization of nutrients. Multiple physical features at different scales regulated the spatial variation of phytoplankton biomass. Phytoplankton biomass was initialized by an improved irradiance field driven by reduced turbidity together with a rapid development of subsurface stratification at the main plume front (isohaline of 23) downstream from the turbidity maximum zone. Phytoplankton blooms did not occur until outcrops located within the main front that were characterized by surface convergence and downwelling, which contributed to large algal biomass by mass trapping and enhanced light penetration. Wave-like features were detected seaward of the main front, coinciding with deacceleration of currents, indicating that they are front-released internal waves that increase algal retention time. This study revealed the critical role of small-scale processes near the plume front in triggering phytoplankton blooms under the large-scale context of improved light conditions, coastal upwelling and nutrient additions from intruding oceanic waters.
Restoration Of Seagrass Habitat Leads To Rapid Recovery Of Coastal Ecosystem Services, Robert J. Orth, Jonathan S. Lefcheck, Karen S. Mcglathery, Lillian Aoki, Mark Luckenbach, Kenneth A. Moore, Matthew P.J. Oreska, Richard A. Snyder, David J. Wilcox, Bo Lusk
Restoration Of Seagrass Habitat Leads To Rapid Recovery Of Coastal Ecosystem Services, Robert J. Orth, Jonathan S. Lefcheck, Karen S. Mcglathery, Lillian Aoki, Mark Luckenbach, Kenneth A. Moore, Matthew P.J. Oreska, Richard A. Snyder, David J. Wilcox, Bo Lusk
VIMS Articles
There have been increasing attempts to reverse habitat degradation through active restoration, but few largescale successes are reported to guide these efforts. Here, we report outcomes from a unique and very successful seagrass restoration project: Since 1999, over 70 million seeds of a marine angiosperm, eelgrass (Zostera marina), have been broadcast into mid-western Atlantic coastal lagoons, leading to recovery of 3612 ha of seagrass. Well-developed meadows now foster productive and diverse animal communities, sequester substantial stocks of carbon and nitrogen, and have prompted a parallel restoration for bay scallops (Argopecten irradians). Restored ecosystem services are approaching historic levels, but we …
Salinity And Simulated Herbivory Influence Spartina Alterniflora Traits And Defense Strategy, Serina Sebilian Wittyngham
Salinity And Simulated Herbivory Influence Spartina Alterniflora Traits And Defense Strategy, Serina Sebilian Wittyngham
VIMS Articles
Sea level rise is expected to push saline waters into previously fresher regions of estuaries, and higher salinities may expose oligohaline marshes to invertebrate herbivores typically constrained by salinity. The smooth cordgrass, Spartina alterniflora (syn. Sporobolus alterniflorus), can defend itself against herbivores in polyhaline marshes, however it is not known if S. alterniflora’s defense varies along the mesohaline to oligohaline marsh gradient in estuaries. I found that S. alterniflora from a mesohaline marsh is better defended than plants from an oligohaline marsh, supporting the optimal defense theory. Higher salinity treatments lowered carbon content, C:N, and new stem biomass …
The Effect Of Fertilization On Biomass And Metabolism In North Carolina Salt Marshes: Modulated By Location-Specific Factors, K. M. Czapla, I. C. Anderson, C. A. Currin
The Effect Of Fertilization On Biomass And Metabolism In North Carolina Salt Marshes: Modulated By Location-Specific Factors, K. M. Czapla, I. C. Anderson, C. A. Currin
VIMS Articles
The resilience of salt marshes to sea level rise depends on vertical accretion through belowground biomass production and sediment deposition to maintain elevation above sea level. Increased nitrogen (N) availability from anthropogenic sources may stimulate aboveground biomass production and sediment deposition and, thus, accretion; however, increased N may also negatively impact marsh accretion by decreasing belowground biomass and increasing net CO2 emissions. A study was conducted in Spartina alterniflora‐dominated salt marshes in North Carolina, USA, to determine how responses to fertilization vary across locations with different physical and chemical characteristics. Pore water residence time, inundation time, and proximity …
Net Ecosystem Carbon Balance In A North Carolina, Usa, Salt Marsh, K. M. Czapla, Iris C. Anderson, C. A. Currin
Net Ecosystem Carbon Balance In A North Carolina, Usa, Salt Marsh, K. M. Czapla, Iris C. Anderson, C. A. Currin
VIMS Articles
Salt marshes have among the highest carbon (C) burial rates of any ecosystem and often rely on C accumulation to gain elevation and persist in locations with accelerating sea level rise. Net ecosystem carbon balance (NECB), the accumulation or loss of C resulting from vertical CO2 and CH4 gas fluxes, lateral C fluxes, and sediment C inputs, varies across salt marshes; thus, extrapolation of NECB to an entire marsh is challenging. Anthropogenic nitrogen (N) inputs to salt marshes impact NECB by influencing each component of NECB, but differences in the impacts of fertilization between edge and interior marsh must be …
Relative Impacts Of Global Changes And Regional Watershed Changes On The Inorganic Carbon Balance Of The Chesapeake Bay, Pierre St-Laurent, Marjorie A.M. Friedrichs, Raymond G. Najjar, Elizabeth Shadwick, Hanquin Tian, Yuanzhi Yao
Relative Impacts Of Global Changes And Regional Watershed Changes On The Inorganic Carbon Balance Of The Chesapeake Bay, Pierre St-Laurent, Marjorie A.M. Friedrichs, Raymond G. Najjar, Elizabeth Shadwick, Hanquin Tian, Yuanzhi Yao
VIMS Articles
The Chesapeake Bay is a large coastal-plain estuary that has experienced considerable anthropogenic changeover the past century. At the regional scale, land-use change has doubled the nutrient input from rivers and led to an increase in riverine carbon and alkalinity. The bay has also experienced global changes, including the rise of atmospheric temperature and CO2. Here we seek to understand the relative impact of these changes on the inorganic carbon balance of the bay between the early 1900s and the early 2000s. We use a linked land–estuarine–ocean modeling system that includes both inorganic and organic carbon and nitrogen cycling. Sensitivity …
Linking Antarctic Krill Larval Supply And Recruitment Along The Antarctic Peninsula, John A. Conroy, Christian S . Reiss, Miram R . Gleiber, Deborah K. Steinberg
Linking Antarctic Krill Larval Supply And Recruitment Along The Antarctic Peninsula, John A. Conroy, Christian S . Reiss, Miram R . Gleiber, Deborah K. Steinberg
VIMS Articles
Antarctic krill (Euphausia superba) larval production and overwinter survival drive recruitment variability, which in turn determines abundance trends. The Antarctic Peninsula has been described as a recruitment hot spot and as a potentially important source region for larval and juvenile krill dispersal. However, there has been no analysis to spatially resolve regional-scale krill population dynamics across life stages. We assessed spatiotemporal patterns in krill demography using two decades of austral summer data collected along the North and West Antarctic Peninsula since 1993. We identified persistent spatial segregation in the summer distribution of euphausiid larvae (E. superba plus …
Ecological Associations Of Littoraria Irrorata With Spartina Cynosuroides And Spartina Alterniflora, Caroline Mackenzie Failon, Serina Sebilian Wittyngham, David S. Johnson
Ecological Associations Of Littoraria Irrorata With Spartina Cynosuroides And Spartina Alterniflora, Caroline Mackenzie Failon, Serina Sebilian Wittyngham, David S. Johnson
VIMS Articles
It is well-documented that marsh periwinkles (Littoraria irrorata) consume and inhabit smooth cordgrass (Spartina alterniflora), but their interactions with big cordgrass (Spartina cynosuroides) remain unknown. Plant communities in mesohaline marshes will change as sea-level rise shifts species from salt-intolerant (e.g., S. cynosuroides) plants to salt-tolerant (e.g., S. alterniflora) ones. Therefore, understanding how L. irrorata interacts with different habitats provides insight into this species’ generalist nature and allows us to predict the potential impacts of changing plant communities on L. irrorata. We show, for the first time, that L. irrorata inhabits, climbs, …
Zooplankton Diel Vertical Migration During Antarctic Summer, John A. Conroy, Deborah K. Steinberg, Patrica S. Thibodeau, Oscar Schofield
Zooplankton Diel Vertical Migration During Antarctic Summer, John A. Conroy, Deborah K. Steinberg, Patrica S. Thibodeau, Oscar Schofield
VIMS Articles
Zooplankton diel vertical migration (DVM) during summer in the polar oceans is presumed to be dampened due to near continuous daylight. We analyzed zooplankton diel vertical distribution patterns in a wide range of taxa along the Western Antarctic Peninsula (WAP) to assess if DVM occurs, and if so, what environmental controls modulate DVM in the austral summer. Zooplankton were collected during January and February in paired day-night, depth-stratified tows through the mesopelagic zone along the WAP from 2009-2017, as well as in day and night epipelagic net tows from 1993-2017. The copepod Metridia gerlachei, salp Salpa thompsoni, pteropod …
Impacts Of Water Clarity Variability On Temperature And Biogeochemistry In The Chesapeake Bay, Grace E. Kim, Pierre St-Laurent, Marjorie A.M. Friedrichs, Antionio Mannino
Impacts Of Water Clarity Variability On Temperature And Biogeochemistry In The Chesapeake Bay, Grace E. Kim, Pierre St-Laurent, Marjorie A.M. Friedrichs, Antionio Mannino
VIMS Articles
Estuarine water clarity depends on the concentrations of aquatic constituents, such as colored dissolved organic matter, phytoplankton, inorganic suspended solids, and detritus, which are influenced by variations in riverine inputs. These constituents directly affect temperature because when water is opaque, sunlight heats a shallower layer of the water compared to when it is clear. Despite the importance of accurately predicting temperature variability, many numerical modeling studies do not adequately account for this key process. In this study, we quantify the effect of water clarity on heating by comparing two simulations of a hydrodynamic-biogeochemical model of the Chesapeake Bay for the …
The Role Of Sexual Reproduction In The Maintenance Of Established Zostera Marina Meadows, Andrew J. Johnson, R J. Orth, Ken Moore
The Role Of Sexual Reproduction In The Maintenance Of Established Zostera Marina Meadows, Andrew J. Johnson, R J. Orth, Ken Moore
VIMS Articles
For clonal plants, the role of sexual reproduction in the maintenance of populations can vary widely. Some species are dependent on repeated seedling recruitment. For other species, interactions between adults and seedlings within existing populations can affect seedling survival and limit sexual reproduction in existing populations. Genetic studies of seagrass populations increasingly suggest sexual reproduction is important for the resilience and stability of their populations, but as of yet little observational data support these findings. Because seagrass populations provide important ecosystem services and are threatened with increasing anthropogenic impacts, understanding their reliance on sexual reproduction is evolutionarily and ecologically important. …
Positive Ecological Interactions And The Success Of Seagrass Restoration, Stephanie R. Valdez, Y. Stacy Zhang, Tjisse Van Der Heide, Mathew A. Vanderklift, Flavia Tarquinio, R J. Orth, Brian R. Silliman
Positive Ecological Interactions And The Success Of Seagrass Restoration, Stephanie R. Valdez, Y. Stacy Zhang, Tjisse Van Der Heide, Mathew A. Vanderklift, Flavia Tarquinio, R J. Orth, Brian R. Silliman
VIMS Articles
Seagrasses provide multiple ecosystem services including nursery habitat, improved water quality, coastal protection, and carbon sequestration. However, seagrasses are in crisis as global coverage is declining at an accelerating rate. With increased focus on ecological restoration as a conservation strategy, methods that enhance restoration success need to be explored. Decades of work in coastal plant ecosystems, including seagrasses, has shown that positive species relationships and feedbacks are critical for ecosystem stability, expansion, and recovery from disturbance. We reviewed the restoration literature on seagrasses and found few studies have tested for the beneficial effects of including positive species interactions in seagrass …
Cloud Shadows Drive Vertical Migrations Of Deep-Dwelling Marine Life, Melissa M. Omand, Deborah K. Steinberg, Karen Stamieszkin
Cloud Shadows Drive Vertical Migrations Of Deep-Dwelling Marine Life, Melissa M. Omand, Deborah K. Steinberg, Karen Stamieszkin
VIMS Articles
Many zooplankton and fishes vertically migrate on a diel cycle to avoid predation, moving from their daytime residence in darker, deep waters to prey-rich surface waters to feed at dusk and returning to depth before dawn. Vertical migrations also occur in response to other processes that modify local light intensity, such as storms, eclipses, and full moons. We observed rapid, high-frequency migrations, spanning up to 60 m, of a diel vertically migrating acoustic
scattering layer with a daytime depth of 300 m in the subpolar Northeastern Pacific Ocean. The depth of the layer was significantly correlated, with an ∼5-min lag, …
Alternative Substrates Used For Oyster Reef Restoration: A Review, Taylor Goelz, Bruce Vogt, Troy W. Hartley
Alternative Substrates Used For Oyster Reef Restoration: A Review, Taylor Goelz, Bruce Vogt, Troy W. Hartley
VIMS Articles
Oyster populations and reef habitats have notably declined in the last century around the world. The ecological, economic, and cultural values of oysters have led to a variety of restoration efforts seeking to recover these lost benefits. Limitations of the native oyster shell substrate and the large-scale nature of many restoration projects have resulted in the increased use of a variety of alternative, or artificial, substrates to create reef structures. A text mining package was used to conduct a review of alternative substrates used for oyster restoration. Specifically, the review (1) assessed commonly used alternative substrates, (2) locations where alternative …
Using Long-Term Data From Antarctica To Teach Ocean Acidification, Patrica S. Thibodeau
Using Long-Term Data From Antarctica To Teach Ocean Acidification, Patrica S. Thibodeau
VIMS Articles
There is a mystery to be solved! This lesson plan asks students to identify the Who, What, When, Where, Why, and How of ocean acidification (OA). Global oceans have absorbed approximately a third of the CO2 produced by human activities, such as burning of fossil fuels, over the past decade (Sabine et al. 2004). This accumulation of CO2 in the ocean has lowered average global ocean pH and decreased the concentration of carbonate ions (CO/ ) (Fabry et al. 2008). As a result of this OA, the carbonate chemistry of the global ocean is rapidly changing and affecting marine organisms …