Marine Biology Commons^™

Fecal Pellet Production By North Atlantic Zooplankton, Michael Gibson

Undergraduate Honors Theses

Fecal pellet carbon (FPC) production by zooplankton is a significant component of the ocean’s biological carbon pump: the suite of biological processes that mediate export of carbon to the deep ocean, ultimately leading to the sequestration of atmospheric carbon dioxide in the ocean. In this study, mesozooplankton (zooplankton 0.2 mm to ~2 cm) were collected from the epipelagic zone in the temperate North Atlantic Ocean during day and night in May 2021. Zooplankton were live separated into five size fractions and incubated on board ship in natural surface seawater to measure fecal pellet production rate of the mixed mesozooplankton community. …

Carrying Capacity Of Cultured Bivalves In Cherrystone Inlet, Va, And The Implications Of Spatial Distribution And Environmental Change, Sophia Chirico

Undergraduate Honors Theses

Aquaculture is a growing industry internationally. In the United States, aquaculture of bivalves occurs throughout the Chesapeake Bay. Cherrystone Inlet, a tidal inlet on the Virginia Eastern Shore, is the location of intensive hard clam culture, and recently oyster aquaculture has become common there as well. Given the intensive culture in Cherrystone and similar systems in the Chesapeake, it is important to understand the carrying capacity of the respective bivalves and how they can be grown together. Carrying capacity is defined here as the largest population of individuals that can be supported that allows individuals to reach a harvestable size …

Intertidal Zonation Of Hemichordates In Soft Sediments, Kharis R. Schrage, Juselyn D. Tupik, Jonathan D. Allen

Arts & Sciences Articles

Intertidal zonation of organisms is well studied on rocky shores but less so in soft sediment communities. On rocky shores, communities are two dimensional, with biotic factors such as competition and predation setting the lower bound of a zone, whereas abiotic factors such as desiccation set the upper bound. In soft sediment communities, these patterns persist, but with a dynamic three-dimensional ecosystem occupied by mobile infaunal organisms, zonation can be more difficult to quantify and detect. Hemichordate worms, however, deposit fecal casts at the surface, which can be easily identified and counted, making them a potential model system for identifying …

Asymmetric Root Distributions Reveal Press–Pulse Responses In Retreating Coastal Forests, Tyler C. Messerschmidt, Amy K. Langston, Matthew L. Kirwan

VIMS Articles

The impacts of climate change on ecosystems are manifested in how organisms respond to episodic and continuous stressors. The conversion of coastal forests to salt marshes represents a prominent example of ecosystem state change, driven by the continuous stress of sea-level rise (press), and episodic storms (pulse). Here, we measured the rooting dimension and fall direction of 143 windthrown eastern red cedar (Juniperus virginiana) trees in a rapidly retreating coastal forest in Chesapeake Bay (USA). We found that tree roots were distributed asymmetrically away from the leading edge of soil salinization and towards freshwater sources. The length, number, …

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, …

Monitoring The Abundance Of American Shad And River Herring In Virginia's Rivers - 2017 Annual Report, Eric J. Hilton, Rob Latour, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee

Reports

This report describes the results of the twentieth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2017, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on two fishery-independent monitoring programs, one using staked gillnets in the Rappahannock River (year 2) and the other using anchor gillnets in the Chickahominy River (year 3; a major tributary of the James River),to determine relative abundance and stock structure for the …

Monitoring The Abundance Of American Shad And River Herring In Virginia's Rivers - 2016 Annual Report, Eric J. Hilton, Robert Latour, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee

Reports

This report describes the results of the nineteenth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2016, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on a new fishery-independent monitoring program using staked gillnets to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis) in the Rappahannock River. Data are also reported from two separate fishery-independent monitoring …

Spatiotemporal Abundance Patterns And Ecological Drivers Of A Nearshore U.S. Atlantic Fish And Invertebrate Assemblage, Mark A. Stratton

Dissertations, Theses, and Masters Projects

Taking an ecosystem approach to fisheries requires the consideration of relevant ecological processes within research and assessment frameworks. Processes affecting ecosystem productivity can be categorized as biophysical (climate variability, primary production), exploitative (fishing), or trophodynamic (food web interactions). This dissertation incorporates these three governing processes to characterize spatiotemporal diversity and population abundance trends for multiple demersal fish and invertebrate species that inhabit the nearshore zone (15-30 ft. depth) along portions of the U.S. Atlantic east coast.

Two large marine ecosystems (LMEs) encompass the U.S. East coast – the Southeast and Northeast U.S. Continental Shelf LMEs. The level of connectivity within …

Associated Dataset: Climate Change Impacts On Southern Ross Sea Phytoplankton Composition, Productivity And Export, Daniel E. Kaufman, Marjorie A.M. Friedrichs, Walker O. Smith Jr., Eileen E. Hofmann, Michael S. Dinniman, John C.P. Hemmings

Data

This dataset includes data used in the publication Kaufman et al., 2017, JGR-Oceans, which investigates how these climatic changes in the Ross Sea, Antarctica, may alter phytoplankton composition, primary productivity and export. A one-dimensional version of the Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification was adapted for use in the Ross Sea (MEDUSA-RS). Glider measurements were used to force MEDUSA-RS, which includes diatoms and both solitary and colonial forms of Phaeocystis antarctica. Model performance was evaluated with glider observations, and experiments were conducted using projections of physical drivers for mid- and late-21st century. Additional scenarios examined the …

Juvenile Blue Crab (Callinectes Sapidus) Response To Altered Nursery Habitat, Megan Wood

Dissertations, Theses, and Masters Projects

Habitats of Chesapeake Bay have been altered due to anthropogenic impacts and climate change. Due to these human disturbances, seagrasses have been extirpated from many areas in lower Chesapeake Bay and persisting beds face future losses as water temperatures continue to rise. Further loss of seagrass habitat will negatively impact juvenile blue crabs (Callinectes sapidus) that use seagrass beds as nursery grounds. Habitat degradation allows for more successful introductions of exotic species, and the communities formed from the mixing of native and exotic species are known as emerging ecosystems. Gracilaria vermiculophylla, an exotic macroalga, may be an emerging nursery habitat …

Differential Effects Of Bivalves On Sediment Nitrogen Cycling In A Shallow Coastal Bay, Ashley Smyth, Anna E. Murphy, Iris C. Anderson, Bk Song

VIMS Articles

In coastal ecosystems, suspension-feeding bivalves can remove nitrogen though uptake and assimilation or enhanced denitrification. Bivalves may also retain nitrogen through increased mineralization and dissimilatory nitrate reduction to ammonium (DNRA). This study investigated the effects of oyster reefs and clam aquaculture on denitrification, DNRA, and nutrient fluxes (NOx, NH4 6 +, O2). Core incubations were conducted seasonally on sediments adjacent to restored oyster reefs (Crassostrea virginica), clam aquaculture beds (Mercenaria mercenaria) which contained live clams, and bare sediments from Smith Island Bay, Virginia, USA. Denitrification was significantly higher at oyster reef sediments and clam aquaculture site than bare sediment in …

Nitrogen Isotope Fractionation And Toxin Production During The Uptake Of Micromolar Concentrations Of Nitrate, Ammonium, And Urea By A Marine Dinoflagellate, Christen Taylor Armstrong

Dissertations, Theses, and Masters Projects

Despite an increased global interest in harmful algal bloom (HAB) species and eutrophication, the relationship between nutrient sources and changes in species composition or toxicity remains unclear. Stable isotopes are routinely used to identify and track nitrogen (N) sources to water bodies, as sources can be differentiated based on stable isotope values. While literature is available describing N fractionation by diatoms and coccolithophores, data are greatly lacking regarding isotope fractionation by dinoflagellates. Here we investigate the fractionation of nitrogen isotopes by saxitoxin-producing Alexandrium fundyense, to validate the use of the δ15N of particulate organic matter and identify the nitrogen source …

Modeling Phytoplankton Community Response To Nutrient Loading And Climate Change In A Shallow Temperate Estuary, Sara Aimee Blachman

Dissertations, Theses, and Masters Projects

Phytoplankton account for at least half of all primary production in estuarine waters and are at the center of biogeochemical cycles and material budgets. Environmental managers use water column chlorophyll-a (chl-a) concentrations as a basic water quality indictor, as the problems of eutrophication and hypoxia are intrinsically linked to excessive phytoplankton growth. Evidence suggests that the distribution and frequency of harmful algal blooms may be increasing worldwide. For the most part, phytoplankton communities follow a standard seasonal pattern, with specific groups dominating the assemblage during the time of year when environmental conditions correspond to their requisites for growth. However, climate …

Assemblage Dynamics Of Larval Fishes In The York River Of Virginia And The Chesapeake Bay, Cindy Marlene Marin Martinez

Dissertations, Theses, and Masters Projects

This thesis developed from the VIMS Larval Fish Monitoring Program, which began in 2007 as part of a study comparing the larval fish assemblages of Chesapeake and Delaware Bays. Ribeiro et al. (2015) analyzed data from the first three years of this time series to describe the temporal variation in the larval fish assemblages. After this initial study was completed (three years in duration), the sampling continued at the fixed station near the mouth of the York River, which was used to represent the Chesapeake Bay. For this thesis, therefore, eight years of data (2007-2015) were available to investigate temporal …

Influence Of Structural Complexity And Location On The Habitat Value Of Restored Oyster Reefs, Melissa Ann Karp

Dissertations, Theses, and Masters Projects

In the Chesapeake Bay, < 1% of the historic oyster population remains, and efforts have been increasing to restore oysters and the services they provide. Building reefs that successfully provide ecosystem services–especially habitat and foraging grounds–may require different restoration techniques than those previously used, and success may depend on reef morphology (complexity), location, and environmental conditions. Salinity and habitat complexity are two important factors that may interact to effect benthic communities and predator-prey interactions on restored reefs. The goals of this project were: (1) Characterize the benthic communities on restored oyster reefs in lower Chesapeake Bay, and (2) examine the effects of structural complexity and salinity on benthic communities and predator-prey interactions. A two-year field survey of restored reefs was carried out in four rivers in lower Chesapeake Bay to characterize faunal communities on restored reefs and to quantify the effect of reef complexity on faunal communities. A laboratory mesocosm experiment was conducted to examine the effect of reef complexity on predator foraging. In total, 61 macrofaunal species were identified among all samples, and restored reefs supported on average, 6,169 org/m2 and 67.88 g-AFDW/m2. There were significant differences in the community composition and diversity among the rivers, and salinity was the environmental factor that best explained the observed differences in species composition across the rivers. Salinity and rugosity (i.e., structural complexity) both positively affected diversity, while salinity negatively affected macrofaunal abundance and biomass. Oyster density and rugosity positively affected macrofaunal biomass, and oyster density positively affected mud crab, polychaete, and mussel densities. In the mesocosm experiment, predator foraging, measured by proportion and number of prey consumed, was significantly reduced in the presence of oyster shell structure. However, predators were able to consume more prey when prey density was increased, even in the presence of oyster shell structure. These results combine to enhance our understanding of the benefits of increased habitat complexity for both prey and predators on restored oyster reefs. Increasing complexity worked to increase the abundance, biomass, and diversity of organisms inhabiting restored reefs, and even though predator consumption was reduced in the presence of structure compared to non-structured habitat, predators were able to consume more prey individuals when prey density was increased. Therefore, increasing the structure of oyster reef habitat may benefit prey species by providing refuge habitat, and benefit predators by providing an increased abundance of available prey items.

Modulation Of Watershed Nutrient Loads By Tidal Creek Ecosystems On The Virginia Eastern Shore, Britt Leighanne Dean

Dissertations, Theses, and Masters Projects

While deeper estuaries typically demonstrate predictable responses to increased nutrient loads, responses in shallow systems are more varied, due in part to the presence of multiple benthic autotrophs. Shallow systems are particularly vulnerable to increases in watershed nutrient loads due to their position at the interface between land and open water. The prevailing conceptual model of eutrophication for shallow systems currently describes a succession in the dominant autotroph from seagrass to macroalgae to phytoplankton, but this model does not include benthic microalgae, which can sequester nutrients in photic systems. The Virginia Eastern Shore is characterized by shallow lagoons connected to …

Diel Vertical Distribution Patterns Of Zooplankton Along The Western Antarctic Peninsula, Patricia S. Thibodeau, John A. Conroy, Deborah K. Steinberg

Presentations

The Western Antarctic Peninsula (WAP) is a region that has undergone significant change over the past several decades due to unprecedented increases sea surface temperature and decreases in sea ice cover. The ongoing Palmer Antarctica Long-Term Ecological Research (PAL LTER) study shows that these environmental changes are significantly affecting the marine pelagic ecosystem along the WAP. The goal of this study was to analyze diel vertical distribution patterns of zooplankton along the WAP.

Ontogeny, Behavior, And Ecology Of The Sea Turtle "Lost Years", Kate L. Mansfield

Presentations

Very little is known about sea turtles during their first years at sea, a period described as the sea turtle “lost years”. Filling these data gaps required a new technological approach including the use of small, solar-powered satellite tags and novel tag attachment methods. Data from the first long-term tracks of oceanic stage "lost years" sea turtles provide new insights to early sea turtle life history and ontogeny, revolutionizing how we now perceive the sea turtle “lost years”.

Detecting And Understanding Threats To Eelgrass In The Gulf Of Maine: The Times, They Are A-Changin’, Hillary A. Neckles

Presentations

Eelgrass forms extensive meadows in coastal and estuarine waters throughout northern New England and Atlantic Canada. Threats to ecosystem stability include indirect impacts of watershed development and direct physical alterations associated with coastal construction, boating operations, and commercial fishing. Effects of human activities are exacerbated by natural disturbances such as severe weather events and biotic, geomorphic, and climatic processes. Spatial simulation models have shown even small scale disturbances in eelgrass meadows to require decades for full recovery. However, lack of consistent trend data of sufficient duration, spatial extent, and resolution often impedes anticipating threats before management solutions become cost prohibitive. …

Effects Of Terrestrial–Aquatic Connectivity On An Estuarine Turtle, Robert Isdell, Randolph M. Chambers, Donna M. Bilkovic, Matthias Leu

VIMS Articles

Estuaries world-wide have been modified or fragmented due to human stressors in their terrestrial and aquatic components. Estuary fragmentation often results in reductions in species richness, diversity and connectivity. Effects of human modification on estuaries have been well studied, but less is known about how land use alters connectivity of the terrestrial–aquatic ecotone. We studied the relationship between terrestrial–aquatic connectivity and the distri- bution of an estuarine turtle, diamondback terrapin (Malaclemys terrapin).

Virginia Coastal And Ocean Resource Issues, Virginia Institute Of Marine Science

Reports

Fisheries, aquaculture and marine recreation in Chesapeake Bay and the coastal ocean are important economic engines adding greatly to the economy of the Commonwealth of Virginia. Virginia’s commercial harvest ranks 3rd largest and 7th in total value nationwide. Research at the Virginia Institute of Marine Science (VIMS) shows that Virginia’s water-dependent resource-based industries, including commercial and recreational fisheries, shellfish aquaculture and recreational boating, annually generate $2.53 billion in sales and approximately $1.25–$1.5 billion in income, supporting over 20,000 jobs. . . .

Thin-Layer Sediment Addition Of Dredge Material For Enhancing Marsh Resilience, Virginia Institute Of Marine Science

Reports

Building marsh elevations with sediment delivered from nearby dredging projects is a potentially valuable tool for creating, restoring, and maintaining coastal marshes, and may help slow or reverse losses of wetlands due to coastal development and sea-level rise (Woodhouse et al., 1972). . . .

Water Quality Conditions And Restoration Of Submerged Aquatic Vegetation (Sav) In The Tidal Freshwater James River, 2008, Ken Moore, Betty Berry Neikirk, Erin C. Shields, David Parrish

Reports

In 2008, wild celery (Vallisneria americana), water stargrass (Heteranthera dubia) and hydrilla (Hydrilla verticilata) shoots were transplanted into shallow water sites in the Hopewell region of the tidal James River and sampled for survivorship and growth throughout the SA V growing season. Water quality sampling was conducted at bi-weekly intervals throughout the year for water column nutrients, chlorophyll a, suspended solids, water transparency and other chemical and physical constituents important for SA V growth. Continuous water quality sampling was also conducted along the James River from the mouth of the Chickahominy River to the upstream limits of tidal water at …

Connecting Science And Management For Virginia's Tidal Wetlands, Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

Rivers & Coast is a periodic publication of the Center for Coastal Resources Management, Virginia Institute of Marine Science. The goal of Rivers & Coast is to keep readers well informed of current scientific understanding behind key environmental issues related to watershed rivers and coastal ecosystems of the Chesapeake Bay

Integrated Coastal Management Issues And The Choices We Make, Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

Rivers & Coast is a periodic publication of the Center for Coastal Resources Management, Virginia Institute of Marine Science. The goal of Rivers & Coast is to keep readers well informed of current scientific understanding behind key environmental issues related to watershed rivers and coastal ecosystems of the Chesapeake Bay.

Living Shorelines, Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

Rivers & Coast is a periodic publication of the Center for Coastal Resources Management, Virginia Institute of Marine Science. The goal of Rivers & Coast is to keep readers well informed of current scientific understanding behind key environmental issues related to watershed rivers and coastal ecosystems of the Chesapeake Bay.

Predators In Action : Rapa Whelks Vs. Hard Clams, Juliana M. Harding, Vicki P. Clark, Roger L. Mann

Reports

This booklet gives information and data-based exercises describing ecological and economic connections between introduced rapa whelk Rapana venosa predators and local hard clams Mercenaria mercenaria in the lower Chesapeake Bay. The information is focused to answer the question: "How many hard clams could a rapa whelk eat in one year?

The Chesapeake Bay : A Synopsis, William J. Hargis Jr.

Reports

No abstract provided.

Boat Scarring Effects On Submerged Aquatic Vegetation In Virginia (Year 1), R J. Orth, James R. Fishman, Amy Tillman, Sara Everett, Kenneth A. Moore

Reports

Submerged Aquatic Vegetation (SAV) in Chesapeake Bay has received significant attention in recent decades due to increasing understanding of the importance of these habitats for ecological functions, including fisheries habitat. Yet, SAV in many regions of the bay are at some of the lowest levels of abundance in recorded history. This has led state management agencies to adopt numerous policies and regulations to protect and restore these valuable communities. The Chesapeake Bay 2000 Agreement highlights SAV by recommitting to the goal of protecting and restoring 114,000 acres, revising existing restoration goals and strategies by 2002, and implementing a strategy to …

Oyster Reef Habitat Restoration : A Synopsis And Synthesis Of Approaches; Proceedings From The Symposium, Williamsburg, Virginia, April 1995, Mark Luckenbach, Roger L. Mann, James A. Wesson

Reports

This volume has its origin in a symposium held in Williamsburg, VA in April 1995, though most of the chapters have been significantly revised in the interim. The primary purpose of the symposium was to bring together state fisheries managers involved in fisheries-directed oyster enhancement and research scientists to refine approaches for enhancing oyster populations and to better develop the rationale for restoring reef habitats. We could hardly have anticipated the degree to which this been successful. In the interim between the symposium and the publication of this volume the notion that oyster reefs are valuable habitats, both for oysters …