Research Projects

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Principal Investigator:
Matthew Stefanak
Co-Principal Investigator:
Summary:

The Chesapeake Bay mouth plume is an important yet understudied system that transports large amounts of nutrients and organic matter to the continental shelf. The role of this dynamic plume in structing the population and diet of juvenile fish species that migrate through and (or) reside in this ecotone for at least part of their juvenile stage is largely unknown.

Principal Investigator:
Leone Yisrael
Co-Principal Investigator:
Summary:

Globally, there has been a consistent increase in the volume of hypoxic waters along coasts. Hypoxia can have numerous negative impacts on ecosystems such as modifying nitrogen and phosphorus cycling, altering food webs, degrading fisheries, and making coastal habitats uninhabitable to many economically and ecologically important fish species. Yet, hypoxia is not universally harming marine organisms. Rather some have benefitted from the effects of hypoxia since it can generate regime shifts, where certain species leave habitats since they can no longer tolerate the environmental conditions, leading to other tolerant organisms moving into those oxygen-limiting waters. The Atlantic Brief Squid, Loliguncula brevis, is one such organism.

Principal Investigator:
Cindy Palinkas
Co-Principal Investigator:
Lorie Staver, Horn Point Laboratory, UMCES
Summary:

Shoreline erosion is a major issue globally and in Chesapeake Bay, leading to increased shoreline-stabilization efforts. Recent efforts have focused on living shorelines living shorelines as the preferred method to reduce erosion, but questions remain regarding their effectiveness and potential impacts to adjacent shallow-water benthic habitats over the long term (~10 years). These are pressing management issues in the Chesapeake Bay, where two key open questions challenge widespread adoption of living shorelines: 1) how well living shorelines reduce erosion and persist over time; and 2) how installation impacts SAV habitat and distributions over time. While we have examined these questions at some Chesapeake Bay sites, we have been limited to one design type.

Principal Investigator:
Eric Schott
Co-Principal Investigator:
Tsvetan Bachvaroff, Institute of Marine & Env. Tech., UMCES; Mingli Zhao, Institute of Marine & Env. Tech., University of Maryland Baltimore County
Summary:

Rationale: Blue crab harvests and populations are highly variable in Maryland. Viral disease is a possible cause of blue crab mortalities, but  little is known about viruses in crabs. Interstate transport of blue crabs may introduce new viruses into the bay.

Principal Investigator:
Ryan Woodland
Co-Principal Investigator:
Jeremy Testa, Chesapeake Biological Laboratory, UMCES; Viacheslav Lyubchich, Chesapeake Biological Laboratory, UMCES; Ryan Langendorf, Cooperative Institute for Research in Environmental Studies
Summary:

Ecosystem-based management approaches require an understanding of how environmental conditions interact with living ecosystem components to influence the productivity of harvested species. This project is structured around the central hypothesis that the intensity, duration, and spatial extent of hypoxia will have important and measurable effects on the benthic invertebrate community that anchors much of the Chesapeake Bay demersal food web and contributes to the diet of many economically and ecologically important fishery species. In addition to this central hypothesis, we will evaluate the ecological trade-offs resulting from simultaneous stimulation of food availability and habitat loss (e.g., hypoxia) associated with nutrient loading.

Principal Investigator:
Ming Liu
Co-Principal Investigator:
Brittany Wolfe-Bryant, Jon Farrington, Scott Knoche, Amanda Knobloch, Morgan State University, PEARL
Summary:

The Maryland shellfish aquaculture industry has grown rapidly in the last decade. However, the industry currently consists of only a single species, the Eastern oyster. The monoculture approach leaves the industry vulnerable to disease, climate change, and market fluctuations which pose threats to sustainable industry growth. The soft-shell clam (Mya arenaria) is a commercially important shellfish species harvested in Northeast U.S. coastal waters. This species can grow and reproduce in low salinity waters, which makes it a strong candidate species for culture in Maryland’s portion of the Chesapeake Bay. Further, several Maryland growers have stated their interest in culturing this species.

Principal Investigator:
Elka Porter
Co-Principal Investigator:
Jeffrey Cornwell, Horn Point Laboratory, UMCES; Lawrence Sanford, Horn Point Laboratory, UMCES
Summary:

The potential for net nitrogen removal due to oyster aquaculture is strongly related to the transport and fate of oyster biodeposits. Biodeposits exported from aquaculture sites may enhance denitrification rates elsewhere while mitigating the impacts of organic matter over-enrichment at the aquaculture site, and/or suspended biodeposit organic matter may be denitrified in the water column. Both processes are currently not well understood. We propose a 6-wk ecosystem experiment in six shear-turbulence-resuspension-mesocosm (STURM, Porter et al. 2018a) tanks with tidal resuspension to address these questions. Three tanks will receive daily oyster biodeposit additions to mimic an aquaculture site and three tanks will not in order to represent background natural conditions.

Principal Investigator:
Judith O'Neil
Co-Principal Investigator:
Jeffrey Cornwell, HPL, UMCES; Cassie Gurbisz, St. Mary's College of Maryland; Catherine Wazniak, MDDNR; J. Brooke Landry, MDDNR
Summary:

Management efforts to reduce nutrient pollution have prompted the recovery of submersed aquatic vegetation (SAV) in the Chesapeake Bay (CB), particularly in the Bay’s tidal fresh and oligohaline waters. Unfortunately, benthic filamentous cyanobacteria have also become increasingly common in some of the areas where SAV is expanding the most. Although the prevalence of cyanobacteria is increasing globally, it is relatively uninvestigated in CB where it may threaten the stability and resilience of recovering SAV, disrupt the nutrient balance of SAV beds, which are generally thought to be nutrient sinks, and potentially affect recreational and commercial activities if they produce toxic compounds.

Principal Investigator:
David Nelson
Co-Principal Investigator:
Keith Eshleman, Appalachian Laboratory, UMCES; Joel Bostic, Appalachian Laboratory, UMCES
Summary:

Urbanization has negative environmental impacts, including increasing the export of eutrophying pollutants, such as nitrogen, that reach downstream water bodies. In response, efforts are underway to use “green” stormwater infrastructure (GSI) that enhances infiltration of stormwater and increases retention and removal of pollutants. However, the effectiveness of GSI regarding nitrogen is questionable: there is evidence that some GSI provides no more nitrogen (or sometimes, less) retention than traditional stormwater management. The reason for this apparent limitation of GSI is uncertain and is the focus of the proposed research.

Principal Investigator:
Sairah Malkin
Co-Principal Investigator:
Andrew Thaler, Horn Point Laboratory, UMCES
Summary:

Oyster aquaculture is a rapidly growing industry in Maryland’s Chesapeake waters which stimulates economic activity and may provide a host of ecosystem benefits. A potential concern associated with the intensification of the oyster aquaculture is the local production and accumulation of oyster biodeposits, which can lead to a porewater sulfide accumulation and declining bioturbation, symptoms of declining ecosystem function. Sulfide is naturally removed from the seafloor by the interactions between bioturbating infauna and sulfide oxidizing bacteria. Here, we propose exploring the feasibility of using benthic microbial fuel cells (BMFCs) to accelerate sulfide oxidation in areas of high biodeposit accumulation, below oyster aquaculture cages.

Principal Investigator:
Michael Wilberg
Co-Principal Investigator:
Fellow: Samara Nehemiah
Summary:

Though fish populations typical experience spatially varying mortality, abundance, and fishing pressure, stock assessments commonly model a population that is assumed to be well-mixed. When assumptions about population mixing are not met, these models can result in biased estimates. Spatial population estimates are particularly beneficial to the Chesapeake Bay as this region faces unique challenges as a result of climate change, fishing pressure, and land use within the watershed. Though the Chesapeake Bay supports many important commercial and recreational fisheries, few assessments have estimated abundance of fish within the bay. However, use of spatial models for fisheries management relies on the ability of these models to reliably estimate biological parameters.

Principal Investigator:
Ten-Tsao Wong
Co-Principal Investigator:
Lan Xu
Summary:

We have developed an immersion-based method in fish to eliminate primordial germ cells (PGCs) by silencing a PGC-development-responsible gene, which resulted in the production of reproductively sterile fish. This proposal aims to transfer this fish sterilization technology to produce sterile diploid eastern oysters to avoid triploids mortality issues. The production of sterile diploid oysters without ploidy manipulation could retain the market advantage of sterile oysters and minimize performance compromise. We have identified several candidate genes in eastern oysters that are potentially indispensable for oyster PGC development. Our preliminary experiments by targeting one of the candidate genes, germ-cell-less (gcl), have yielded oysters that are in their third year.

Principal Investigator:
Laura Lapham
Co-Principal Investigator:
Ryan Woodland, Edward Hobbs, Jr.
Summary:

Coastal ecosystems are vulnerable to short term anthropogenic changes such as nutrient loading and longer-term changes such as sea level rise. Together these changes can alter these systems in ways that change the ecosystem services these systems provide. For example, estuaries bury carbon over time which in turn is a major controller for a habitable atmosphere. Carbon can enter estuaries through a number of processes such as photosynthesis, respiration, air-sea exchange, terrestrial runoff, and groundwater input. As it gets buried, it will undergo a series of microbially mediated processes which terminates in the production of methane, a potent greenhouse gas.

Principal Investigator:
Eric Schott
Co-Principal Investigator:
Mingli Zhao
Summary:

Callinectes sapidus supports the most valuable commercial fishery in the Chesapeake Bay and its tributaries. Nationally, the average total dockside value of blue crab fisheries in Maryland, Virginia, North Carolina, Florida, Louisiana and Texas approaches $200 million. Interstate live blue crab transport has increased due to seasonal cycles of crab landings in the Chesapeake regions and changes in allocation of immigration permits for guest workers. The risk of spreading shellfish pathogens through commercial transportation of live seafood has drawn increasing attention, while the potential for blue crab pathogens to be spread by commerce may be underappreciated.

Principal Investigator:
Fellow: Megan Munkacsy
Co-Principal Investigator:
Summary:

In the Chesapeake Bay, resource managers are currently struggling with how to develop policy to inform aquaculture (AQ) industry expansion while supporting environmental Bay goals. Specifically, the recent expansion of submerged aquatic vegetation (SAV) into and near oyster AQ leases is creating tension between definitions of Bay resilience. To inform policy decisions that consider ecosystem service values, I propose applying a multi-criteria decision analysis (MCDA) of in-water and nearshore ecosystem services in Maryland’s Chesapeake Bay.

Principal Investigator:
Louis Plough
Co-Principal Investigator:
Shannon Hood
Summary:

Shellfish aquaculture represents a growing industry with strong potential for global expansion. However, biofouling poses a considerable concern to operations, with conservative estimates indicating farmers spend 5-10% of total costs on biofouling removal. Bioexcavators, such as mudworms, are especially problematic as they affect the condition of the oyster, and also leave behind an unsightly mud blister, which is offputting to the half shell industry which prizes pristine oyster shells. Desiccation, or aerial exposure of oysters and cages, has demonstrated marked success in mitigating biofouling, including bioexcavators, but has also been associated with a growth penalty in some desiccated oysters.

Principal Investigator:
Fellow: Mariah Kachmar
Co-Principal Investigator:
Summary:

The Ostreid herpesvirus 1 (OsHV-1) and its microvariants are highly virulent pathogens that cause mass mortalities of oysters and pose a threat to the shellfish aquaculture industry globally. OsHV-1 causes economically devastating mass mortality events up to 100% in the Pacific oyster (Crassostrea gigas). However, OsHV-1 and its variants lack host specificity and are known to infect a range of bivalve species and be carried by the European green crab (Carcinus maenas). There is a lack of testing and research on the East coast of the United States, including in the Chesapeake and Maryland Coastal Bays where aquaculture is an important industry for food production and restoration efforts.

Principal Investigator:
Greg Silsbe
Co-Principal Investigator:
Anna Windle
Summary:

A spectral library of remote sensing reflectance for major phytoplankton taxonomic groups in the Chesapeake Bay will be developed using measured and modeled inherent optical properties as inputs into radiative transfer equations (HydroLight TM). The spectral library will be used to develop a phytoplankton discrimination algorithm in order to distinguish major phytoplankton taxa and sediment types in Chesapeake Bay waters. Hyperspectral remote sensing reflectance spectra collected from an unoccupied aircraft system (UAS) or the upcoming hyperspectral satellite mission, PACE, can be used as inputs to the algorithm to effectively quantify and map phytoplankton taxonomic-specific biomass.

Principal Investigator:
Dennis Whigham
Co-Principal Investigator:
Karen Kettenring, Utah State University; Melissa McCormick, Smithsonian Environmental Research Center; Andrew Baldwin, University of Maryland College Park
Summary:
A European haplotype of Phragmites australis (common reed) is an increasingly widespread invasive plant in Chesapeake Bay tidal wetlands. The spread of Phragmites has been promoted by disturbance and nutrient enrichment, resulting in threats to native plants and animals and triggering changes in ecological processes in wetlands. Cultural issues such as loss of vision-scape and access to water are important public concerns. Phragmites removal is possible but difficult, and thus is likely to be cost-effective over relatively small areas.
Principal Investigator:
Elka Porter
Co-Principal Investigator:
Jeffrey Cornwell, University of Maryland Center for Environmental Science, Horn Point Laboratory; Lawrence Sanford, University of Maryland Center for Environmental Science, Horn Point Laboratory
Summary:
The net environmental impacts of oyster aquaculture are strongly related to the transport and fate of biodeposits, though little is known of their physical and biological properties. Biodeposits exported from aquaculture sites may result in net denitrification elsewhere while mitigating the impacts of organic matter over-enrichment at the aquaculture site. Consequently, the susceptibility of biodeposits to erosion and long range transport is key to determining the ecological effects of oyster aquaculture. Current oyster biodeposit models do not use realistic values of critical shear stress, (?c), or values of the cumulative suspended mass (CSM) available for export at aquaculture sites.
Principal Investigator:
Sujay Kaushal
Co-Principal Investigator:
Shuiwang Duan, University of Maryland College Park
Summary:

Salinization is increasingly affecting many watersheds, significantly impacting drinking water resources and infrastructure, reducing stability and resilience of aquatic ecosystems, and potentially hindering stream and river restoration efforts. Salinization is related to deicer use on roadways with additional contributions from accelerated weathering of impervious surfaces, water softeners, and sewage. The concentrations of chloride observed in many urban streams in Maryland now exceed the limit of 250 mg/L established by the U.S. EPA for chronic toxicity to freshwater life. These observed ranges and extreme fluctuations in salinity can mobilize nitrogen, phosphorus, base cations, and toxic metals from sediments to streams due to enhanced ion exchange and solubility.

Principal Investigator:
Jeremy Testa
Co-Principal Investigator:
Lora Harris, University of Maryland Center for Environmental Sciences, Chesapeake Biological Laboratory; Lawrence Sanford, University of Maryland Center for Environmental Science, Horn Point Laboratory
Summary:
Current efforts to restore natural oyster reefs and a growing oyster aquaculture industry in Maryland will serve to support an increased prevalence of oysters in Chesapeake Bay. While these activities will support continued commercial harvests and restored natural habitats, elevated oyster numbers will also lead to changes in estuarine biogeochemistry relevant to water quality restoration. Recent studies have illustrated that oyster communities are associated with extremely high rates of nitrogen removal and newly proposed BMP guidelines will serve to give nitrogen removal credits to aquaculture activities.
Principal Investigator:
Genevieve M. Nesslage
Co-Principal Investigator:
Michael Wilberg, University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory
Summary:
Atlantic menhaden (Brevoortia tyrannus) is a migratory forage fish that plays a vital role in Chesapeake Bay and Mid-Atlantic marine ecosystems by linking production at lower trophic levels with piscivorous predators. Given the critical ecosystem services menhaden provide as forage, the Atlantic States Marine Fisheries Commission is currently developing an Ecosystem-Based Fisheries Management (EBFM) approach to stewardship of the menhaden resource. Managers and stakeholders are particularly interested in potential impacts of menhaden management on its primary predator, Atlantic striped bass (Morone saxatilis).
Principal Investigator:
Louis Plough
Co-Principal Investigator:
Matthew B. Ogburn, Smithsonian Environmental Research Center
Summary:
Anadromous alosine fishes (river herrings and shads) are critically important to ecosystem function, economies, and cultures of coastal communities, but have seen major declines in the mid-Atlantic region and the Chesapeake Bay in particular. We have developed and demonstrated the effectiveness of new monitoring tools for river herring (alewife and blueback herring) including environmental DNA (eDNA) and sonar image-based run counts that are rapidly improving our ability to study these species. However, additional eDNA monitoring of American shad and hickory shad, which lacks baseline data, is needed to establish habitat use in rivers across the mid-Atlantic.
Principal Investigator:
Ming Liu, Morgan State University
Institution:
Co-Principal Investigator:
Amber DeMarr, Morgan State University; Richard Lacouture, Morgan State University
Summary:

Triploid eastern oysters are an important component of the Maryland aquaculture industry because of their fast growth and sustained high meat yield. Commercially, triploids are produced by mating tetraploid oysters with normal diploid oysters. Developing tetraploid stock is crucial to meeting the growing demand for Maryland triploid oysters. However, it is challenging to produce and maintain excellent tetraploid lines for the benefit of industry. In short, there is a clear and pressing need for triploid and tetraploid lines that have region-specific beneficial characteristics, especially tolerance to low-salinity environments. In this project, we will establish the first generation of tetraploid stock derived from Maryland local oyster populations.

Since 1977, Maryland Sea Grant has funded scientific research relevant to the Chesapeake Bay and the Maryland residents who conserve, enjoy, and make their living from it. We strive to fund projects that both advance scientific knowledge and offer practical results benefiting ecosystems, communities, and economies throughout the Chesapeake Bay region.

Click on an individual project to find out more. Search current and past research projects here.

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