Phytoplankton production in the Delaware Estuary: temporal and spatial variation.

ABSTRACT: Phytoplankton production in the Delaware Estuary (USA) was measured over several seasonal cycles (1980-1985). Seasonal variability in daily area1 production (JP; g C m-2 d-l) was dlrectly related to chlorophyll concentrations in the upper estuary, ranging from a maximum of 1.1 g C m-\u27 d-\u27 In summer to a minlmum of d-l) dunng summer in the presence of low phytoplankton biomass (2 to 10 kg Chl I-\u27), and in mid-estuary [2.6 g C d-l) during the spring diatom bloom (50 to 60 yg Chll-l). Desplte the occurrence of maximum nutnent concentrations in the freshwater region, highest JP and 90 % of the annual production occurred in the lower estuary, down-stream from the turbidity maximum. The presence of the turbidity maximum immediately downstream from major anthropogenic nutrient sources restricts phytoplankton growth, and limits biomass accumulation below nuisance levels. Annual production for the 1981-1985 period averaged 307 g Cm-2 and displayed marked inter-annual variability. Llght availability is the predominant regulator of production in the estuary. Although growth was light-limited, neither chlorophyll specific produchon nor the light intensity at which photosynthesis saturates was related to the mean light intensity in the mixed surface-layer. These results suggest that photoadaptive response times are slower than the vertical mlxing rate and that photoadaptation is of mlnor significance to overall production in the system

2008 Great Bay Water Quality (Datasonde) Monitoring Program

In situ water quality assessment has become an important source of data for monitoring, research and management activities in estuaries nationwide. As part of the National Estuarine Research Reserve System, the Great Bay System-Wide Monitoring Program (SWMP) produces in situ water quality data for four sites in and around Great Bay. This project extends the SWMP program to include year-round in situ data for a station at the University of New Hampshire Coastal Marine Lab pier at the mouth of the Piscataqua River and summmer data for a station in the Salmon Falls (SF) River. This suite of stations provides a comprehensive in situ sampling array that monitors the major rivers and open estuary locations within the Great Bay estuarine system

2004 Great Bay Organic Nitrogen (PON & DON) and Light Extinction (PAR) Monitoring Program

Nitrogen is most often considered to be the limiting nutrient for plant growth in marine waters. As a result, knowledge of nitrogen loading and ambient water-column concentrations are considered to be critical to understanding the response of aquatic ecosystems to nutrient over-enrichment—a process known as eutrophication when it results in the excess production of organic matter. Plant production in many estuarine systems may also be limited by light availability as a result of high levels of turbidity in the water resulting from sediments, dissolved organic matter, and phytoplankton in the water column. Light limitation resulting from human-induced increases in turbidity is known to be particularly deliterious to seagrass production/distribution in some ecosystems and also play an important role in determining how phytoplankton respond to nutrient enrichment. EPA is developing water qulaity criteria for estuaries that require knowledge of both total nitrogen and light availability (measured as photsynthetically active radiation, PAR). Through the National Estuarine Research Reserve (NERR) System-Wide Monitoring Program (SWMP), inorganic nutrient concentrations, chlorophyll-a concetration, and a number of hydrographic and water quality parameters are sampled on a monthly basis at 7 sites in the Great Bay system. In addition, these same parameters, as well as bacteria concentrations, are measured at a number of sites in Great Bay and Hampton Harbor through the National Coastal Assessment (NCA) funded through the EPA. This project takes advantage of these existing monitoring activities to collect and analyze for particulate organic nitrogen (PON), dissolved organic nitrogen (DON) and photosynthetically active radiation (PAR) at a up to 10 existing sample sites in the New Hampshire seacoast region. When combined with existing dissolved inorganic nitrogen measurements, PON and DON allow the entire Total Nitrogen (TN) pool to be quantified. PAR measurements provide, for the first time, an estimate of the light availability in the system

2004 Great Bay Water Quality Monitoring Program (DataSonde)

In situ water quality assessment has become an important source of data for monitoring, research and management activities in estuaries nationwide. As part of the National Estuarine Research Reserve System, the Great Bay System-Wide Monitoring Program (SWMP) produces in situ water quality data for four sites in and around Great Bay. This project extends the SWMP program to include year-round in situ data for a station at the University of New Hampshire Coastal Marine Lab pier at the mouth of the Piscataqua River and summmer data for a station in the Salmon Falls (SF) River. This suite of stations provides a comprehensive in situ sampling array that monitors the major rivers and open estuary locations within the Great Bay estuarine system

2005 Great Bay Organic Nitrogen (PON & DON) and Light Extinction (PAR) Monitoring Program

Nitrogen is most often considered to be the limiting nutrient for plant growth in marine waters. As a result, knowledge of nitrogen loading and ambient water-column concentrations are considered to be critical to understanding the response of aquatic ecosystems to nutrient over-enrichment—a process known as eutrophication when it results in the excess production of organic matter. Plant production in many estuarine systems may also be limited by light availability as a result of high levels of turbidity in the water resulting from sediments, dissolved organic matter, and phytoplankton in the water column. Light limitation resulting from human-induced increases in turbidity is known to be particularly deliterious to seagrass production/distribution in some ecosystems and also play an important role in determining how phytoplankton respond to nutrient enrichment. EPA is developing water qulaity criteria for estuaries that require knowledge of both total nitrogen and light availability (measured as photsynthetically active radiation, PAR). Through the National Estuarine Research Reserve (NERR) System-Wide Monitoring Program (SWMP), inorganic nutrient concentrations, chlorophyll-a concetration, and a number of hydrographic and water quality parameters are sampled on a monthly basis at 7 sites in the Great Bay system. This project takes advantage of these existing monitoring activities to collect and analyze for particulate organic nitrogen (PON), dissolved organic nitrogen (DON) and photosynthetically active radiation (PAR) at existing sample sites in the New Hampshire seacoast region. When combined with existing dissolved inorganic nitrogen measurements, PON and DON allow the entire Total Nitrogen (TN) pool to be quantified. PAR measurements provide an estimate of the light availability in the system

2008 Great Bay Organic Nitrogen (PON & DON) and Light Extinction (PAR) Monitoring Program

This project takes advantage of these existing monitoring activities to collect and analyze for particulate organic nitrogen (PON), dissolved organic nitrogen (DON) and photosynthetically active radiation (PAR) at existing sample sites in the New Hampshire seacoast region. When combined with existing dissolved inorganic nitrogen measurements, PON and DON allow the entire Total Nitrogen (TN) pool to be quantified. PAR measurements provide an estimate of the light availability in the system

2006 Great Bay Organic Nitrogen (PON & DON) and Light Extinction (PAR) Monitoring Program

Nitrogen is most often considered to be the limiting nutrient for plant growth in marine waters. As a result, knowledge of nitrogen loading and ambient water-column concentrations are considered to be critical to understanding the response of aquatic ecosystems to nutrient over-enrichment—a process known as eutrophication when it results in the excess production of organic matter. Plant production in many estuarine systems may also be limited by light availability as a result of high levels of turbidity in the water resulting from sediments, dissolved organic matter, and phytoplankton in the water column. Light limitation resulting from human-induced increases in turbidity is known to be particularly deliterious to seagrass production/distribution in some ecosystems and also play an important role in determining how phytoplankton respond to nutrient enrichment. EPA is developing water qulaity criteria for estuaries that require knowledge of both total nitrogen and light availability (measured as photsynthetically active radiation, PAR). Through the National Estuarine Research Reserve (NERR) System-Wide Monitoring Program (SWMP), inorganic nutrient concentrations, chlorophyll-a concetration, and a number of hydrographic and water quality parameters are sampled on a monthly basis at 7 sites in the Great Bay system. This project takes advantage of these existing monitoring activities to collect and analyze for particulate organic nitrogen (PON), dissolved organic nitrogen (DON) and photosynthetically active radiation (PAR) at existing sample sites in the New Hampshire seacoast region. When combined with existing dissolved inorganic nitrogen measurements, PON and DON allow the entire Total Nitrogen (TN) pool to be quantified. PAR measurements provide an estimate of the light availability in the system

2005 Great Bay Water Quality (DataSonde) Monitoring Program

In situ water quality assessment has become an important source of data for monitoring, research and management activities in estuaries nationwide. As part of the National Estuarine Research Reserve System, the Great Bay System-Wide Monitoring Program (SWMP) produces in situ water quality data for four sites in and around Great Bay. This project extends the SWMP program to include year-round in situ data for a station at the University of New Hampshire Coastal Marine Lab pier at the mouth of the Piscataqua River and summmer data for a station in the Salmon Falls (SF) River. This suite of stations provides a comprehensive in situ sampling array that monitors the major rivers and open estuary locations within the Great Bay estuarine system

2003 Great Bay Water Quality (DataSonde) Monitoring Program

In situ water quality assessment has become an important source of data for monitoring, research and management activities in estuaries nationwide. As part of the National Estuarine Research Reserve System, the Great Bay System-Wide Monitoring Program (SWMP) produces in situ water quality data for four sites in and around Great Bay. This project extends the SWMP program to include year-round in situ data for a station at the University of New Hampshire Coastal Marine Lab pier at the mouth of the Piscataqua River and summmer data for a station in the Salmon Falls (SF) River. This suite of stations provides a comprehensive in situ sampling array that monitors the major rivers and open estuary locations within the Great Bay estuarine system

2006 Great Bay Water Quality (DataSonde) Monitoring Program

In situ water quality assessment has become an important source of data for monitoring, research and management activities in estuaries nationwide. As part of the National Estuarine Research Reserve System, the Great Bay System-Wide Monitoring Program (SWMP) produces in situ water quality data for four sites in and around Great Bay. This project extends the SWMP program to include year-round in situ data for a station at the University of New Hampshire Coastal Marine Lab pier at the mouth of the Piscataqua River and summmer data for a station in the Salmon Falls (SF) River. This suite of stations provides a comprehensive in situ sampling array that monitors the major rivers and open estuary locations within the Great Bay estuarine system