Geochemical factors impacting nitrifying communities in sandy sediments.

Sandy sediment beaches covering 70% of non-ice-covered coastlines are important ecosystems for nutrient cycling along the land-ocean continuum. Subterranean estuaries (STEs), where groundwater and seawater meet, are hotspots for biogeochemical cycling within sandy beaches. The STE microbial community facilitates biogeochemical reactions, determining the fate of nutrients, including nitrogen (N), supplied by groundwater.

Blooms of the harmful algae Margalefidinium polykrikoides and Alexandrium monilatum alter the York River Estuary microbiome.

Harmful algal blooms (HABs) cause damage to fisheries, aquaculture, and human health around the globe. However, the impact of HABs on water column microbiomes and biogeochemistry is poorly understood. This study examined the impacts of consecutive blooms of the ichthyotoxic dinoflagellates Margalefidinium polykrikoides and Alexandrium monilatum on the water microbiome in the York River Estuary, Chesapeake Bay, USA.

Microbially mediated nitrogen removal and retention in the York River Estuary.

Denitrification, anaerobic ammonium oxidation and dissimilatory nitrate reduction to ammonium (DNRA) are important microbial processes determining the fate of nitrogen (N) in estuaries. This study examined these processes in sediments of the York River Estuary, a tributary of Chesapeake Bay, and investigated environmental and microbial drivers of the rates of denitrification and DNRA. Nitrate reduction followed a consistent pattern throughout the year and across the estuary with nitrogen removal, primarily through denitrification, decreasing from the head of the estuary to the mouth and nitrogen retention, through DNRA, following the opposite pattern.

Ecosystem-based management for military training, biodiversity, carbon storage and climate resiliency on a complex coastal land/water-scape.

The Defense Coastal/Estuarine Research Program (DCERP) was a 10-year multi-investigator project funded by the Department of Defense to improve understanding of ecosystem processes and their interactions with natural and anthropogenic stressors at the Marine Corps Base Camp Lejeune (MCBCL) located in coastal North Carolina. The project was aimed at facilitating ecosystem-based management (EBM) at the MCBCL and other coastal military installations. Because of its scope, interdisciplinary character, and duration, DCERP embodied many of the opportunities and challenges associated with EBM, including the need for explicit goals, system models, long-term perspectives, systems complexity, change inevitability, consideration of humans as ecosystem components, and program adaptability and accountability.

Bioreactivity and Microbiome of Biodeposits from Filter-Feeding Bivalves.

Bivalves serve an important ecosystem function in delivering organic matter from pelagic to benthic zones and are important in mediating eutrophication. However, the fate of this organic matter (i.e.

Variation in benthic metabolism and nitrogen cycling across clam aquaculture sites.

As bivalve aquaculture expands globally, an understanding of how it alters nitrogen is important to minimize impacts. This study investigated nitrogen cycling associated with clam aquaculture in the Sacca di Goro, Italy (Ruditapes philipinarum) and the Eastern Shore, USA (Mercenaria mercenaria). Ammonium and dissolved oxygen fluxes were positively correlated with clam biomass; R.

Base flow nutrient discharges from lower delmarva peninsula watersheds of virginia, USA.

Proper management of shallow coastal systems, which are vulnerable to nutrient enrichment, requires knowledge of land use impacts on nutrient discharges. This study quantified base flow nutrient concentrations and yields for 1 yr (May 2001-April 2002) from 14 first-order streams on the Virginia Eastern Shore (VaES) on the Delmarva Peninsula and assessed their relationships with land cover and soil drainage class in their watersheds. Base flow water discharge rates (1.