Nutrients Why monitor nutrients? Plant and algae growth Carbon, nitrogen, phosphorus, oxygen, silica, magnesium, potassium, calcium, iron, zinc, and copper Health concerns Reproductive problems Methemoglobinemia in infants Global warming Ozone depletion

Nutrients Eutrophication High nutrient concentrations stimulate excessive algal blooms When the algal blooms decompose, the decomposing bacteria deplete the oxygen in the system. Organic production (algae) can also lead to sediment accumulation. Because of these impacts, nutrients such as nitrogen and phosphorus are monitored, and used as indicators of estuarine health.

Nutrients Phytoplankton blooms Hypoxic Anoxic Could cause decrease of SAV Harmful Hypoxic Anoxic

Nutrient Sources Natural Sources Freshwater running over geologic formations Decomposing organic matter Extraction from the atmosphere

Nutrient Sources Anthropogenic Sources Atmospheric deposition Surface water Groundwater Atmospheric deposition = fossil fuel burning by power plants and automobiles; may fall to land directly or with precipitation Surface water = point and non-point source discharges; effluent from wastewater treatment plants, urban stormwater runoff, lawn and agriculture fertilizer runoff, industrial discharges, and livestock wastes Groundwater = underground seepage from agricultural fields and failing septic systems

Nutrient Levels Water & Wastewater samples Milligrams per liter mg/L Micrograms per liter μg/L Air, soils, sludges, & semisolids Parts per million ppm Parts per billion ppb Mass per unit volume Mass per unit mass Usually, ppm = mg/L, if specific gravity is correct Since a liter of water weighs ~ 1000 g or 1000000 mg

Nutrient Levels Safe Water Drinking Act Passed in 1974 Maximum Contaminant Levels National Primary Drinking Water Regulations Safe Water Drinking Act passed in 1974 US EPA set Maximum Contaminant Level Goals (MCLG’s) (non-enforceable levels) Nitrates = 10 ppm Nitrites = 1 ppm US EPA set Maximum Contaminant Levels (MCL’s) (enforceable levels) for public water systems These drinking water standards and the regulations for ensuring these standards are met, are called National Primary Drinking Water Regulations. All public water supplies must abide by these regulations. (see US EPA website)

The Different Forms of Nutrients Determined by environmental conditions Nitrogen: Nitrate NO3- Nitrite NO2- NO NO2 Ammonium NH4+ Ammonia NH3 Urea Organic form NOx Oxidation states of nitrogen Seven Nitrate (NO3-) Nitrite (NO2-) NO (nitric oxide) NO2 (nitrogen dioxide) Together called Nox (“nox”) Ammonium (NH4+) Ammonia (NH3) Urea

Forms of Phosphorus Phosphorus occurs naturally in rocks Inorganic Weathering releases phosphate ions (PO4-3) Inorganic Orthophosphates Polyphosphates (Metaphosphates) Organic phosphate Phosphorus occurs naturally in rocks and other mineral deposits. Weathering of these rocks releases phosphate ions in solution

Forms of Phosphorus Orthophosphates Readily available to the biological community Typically found in low concentrations in unpolluted waters H3PO4 H2PO4- HPO42- PO43-

Forms of Phosphorus Organic Phosphate bound or tied up in plant tissue, waste solids, or other organic material When decomposed thru bacterial action, phosphate released and returned to environment

Silica in Water Silicon dioxide SiO2 + 2H2O H4SiO4 Three forms: H4SiO4 (monosilicic acid) Three forms: Reactive Colloidal Suspended particles Young seawaters that are highly undersaturated with H4SiO4 are far more corrosive to SiO4 (there is more water to combine with it). Older seawaters that have been dissolving and accumulating H4SiO4 over hundreds of thousands of years are less corrosive. Reactive = SiO2 dissolved in water, creating monosilicic acid (H4SiO4); generally un-ionized in this form at most natural pH levels Collodial = either silicon that has polymerized with multiple units of silicon dioxide or silicon that has formed loose bonds with organic compounds Suspended particles (quartz = sand)

The Nitrogen Cycle Atmospheric N Takes up ~ 80% of the Earth’s atmosphere, but mostly inaccessible Bacteria and cyanobacteria can “fix” nitrogen gas (change it to an inorganic form; protein) thereby making it accessible to other organisms, especially plants Electrical discharge (lightening) can also remove atmospheric N; in this case nitrogen is oxidized to nitrous oxide which if further oxidized by ozone to nitrogen dioxide Combustion processes (such as in automobiles) can also remove atmospheric N Quantity and form of nitrogen in water is closely related to dissolved oxygen levels Nitrification = aerobic conditions; bacteria breakdown ammonia into nitrite and then to nitrate (could be limited by low levels of DO, then ammonia and nitrite could accumulate); oxidation Denitrification = anaerobic conditions; bacteria convert nitrate to nitrite and then to nitrogen gas; reduction Animals and human beings are dependant upon plants for their nitrogen to make proteins. Within animals, protein is largely used for growth and repair of muscle tissue. Nitrogen compounds are then released in the waste products of the body = urea in urine Urea is then either nitrified or denitrified by bacteria Nitrate and urea are highly soluble in water which facilitates their transport to estuaries by runoff Ammonium is also soluble in water, where it can be transformed to ammonia in low oxygen environments

Phosphate Cycle Phosphorus enters the environment from rocks or deposits laid down long ago (uplifting, erosion, weathering, and leaching) P can also be found in high concentrations in sedimentary rocks containing fossilized wastes or remains of marine plants and animals. This phosphate can be mined and used in commercial fertilizers. Main P rock = apatite = commercially available form of rock containing calcium, iron, chlorine, and several other elements in varying quantities Bird and bat guano contains high concentrations of P. Ecosystems containing the breeding and feeding grounds are often very productive Soluble forms are washed into streams and rivers where it becomes available to plants as a nutrient. Dead plants/phytoplankton releases P back to the environment At the bottom of the ocean, chemical reactions with seawater can also result in the precipitation of phosphorus to form nodules on the ocean floor.

Dissolution of seafloor basalts = 7% Inputs: Riverine = 80% Aeolian deposition = 7% Dissolution of seafloor basalts = 7% Hydrothermal vents = 6% Inputs: Riverine = 80% Aeolian deposition = 7% (pertaining to the action or effect of the wind) Dissolution of seafloor basalts = 7% Seafloor hydrothermal inputs = 6% Outputs: Sedimentation of biogenic opal

Turbidity Measure of relative sample clarity How much light is scattered by suspended particles Turbidity increases with increased suspended particulate matter and increased plankton abundance

Turbidity Measurements Slow-moving, deep waters Secchi disk Rule of Thumb: light penetrates 2-3x Secchi depth Secchi disk = tells us how far light can penetrate in meters; primarily used as an indicator of algal abundance and general water productivity

Turbidity Measurements Fast-moving, shallow water Turbidimeter (Nephelometer) Nephelometric Turbidity Units (NTU’s) Turbidimeter = measures the scattering of light Has a photocell set at 90 degrees to the direction of the light beam to estimate scattered rather than absorbed light This measurement generally provides a very good correlation with the concentration of particles in the water that affect clarity

NC Waters Average NTU’s Salt ~ 25 Fresh ~ 50 http://h2o.enr.state.nc.us/

Factors Affecting Turbidity High Flow Rate Soil Erosion Urban Runoff Wastewater & Septic System Effluent Decaying plants & animals Bottom feeding fish Algal blooms Flooding High flow rates = fast running water carries more and larger sediment. Rains pick up particles from land and carry it to surface waters; particulates may be resuspended from the bottom if the flow is high enough Soil erosion = caused by disturbance of a land surface, such as Building and road construction Forest fires Logging Mining Urban runoff = runoff from streets, industrial, commercial and residential areas. Concrete has replaced natural settling areas so increased sediment carried through storm drains to creeks and rivers Wastewater and septic effluent = from wastewater treatment plants containing food, human waste etc. Most removed from plant – but not all!! Decaying plants and animals Bottom feeding fish = carp stir up sediments Algal blooms = algal production is enhanced when nutrients are released from bottom sediments during seasonal turnovers and changes in water current Flooding = as flood waters recede, they bring along inorganic and organic particles from the land surface, and contribute this to the water body

Sediment Analysis Ogeechee Corer Ogeechee(tm) Sand Corers The Wildco® Ogeechee™ sand corer is the first sampler to effectively sample most bottom sands. The Ogeechee™ sand corer is a low cost core sampler designed for coring in fresh, salt, or brackish waters. The top closing valve is located inside its solid 316 stainless steel head assembly, and is under full control of the operator by means of its own closing line. The closing valve design provides for long life of both the valve and valve seat and for tight sealing against air leakage under sandy conditions. When cleaning and lubricating is desired, the entire valve and valve seat are easily removed, cleaned, and/or replaced. The Ogeechee™ sand corer was designed to sample in swiftly moving water with the use of an extension handle up to 4.5 meters (15 feet) long. Extension handles allow both twisting and downward pressure to work together to obtain a long core sample in firm or sandy bottoms. In depths greater than 4.5 meters (15 feet), the Ogeechee™ Sand-Pounder corer can be hammered into the sand with the optional drive hammer. The drive hammer is used to drive only the Ogeechee™ Sand-Pounder corer into the sediments and sand by repeated lifting and dropping of the drive hammer. The drive hammer will severely damage other corers. Caution: clays, heavy soils, or long cores may make sampler removal difficult, requiring a power winch! Ogeechee head assembly fits all 51 mm (2") threaded corer tubes and their accessories. Center pivot for low bottom disturbance • Tapered scoop edges for a clean cut • Heavy duty hinges for high impact work • Hefty scoop volume: 8200 mL • 316 SS scoops and underlip or all 316 SS • Removable stainless steel top screens • Self-releasing pinch-pin™ Widely used in fresh and salt water for taking samples of hard bottoms such as sand, gravel, consolidated marl or clay, this sturdy dredge is a deliberately heavy device for biting deep into the bottom and has proven success at invertebrate recovery. The simple design means it is simple to use. Heavy duty hinges and hinge pin can absorb thousands of bottom impacts. Self-closing scoops have center pivot closing action. When the scoops strike the bottom, their tapered cutting edges penetrate well with very little sample disturbance. An attached underlip wipes the scoop clean of pebbles and cobble that would interfere with closing. By the same token, removable side plates prevent the lateral loss of sample as scoops close. This well-regarded self-closing sampler uses our patented spring-loaded pinch-pin™ that releases when cable or line slackens. A safety pin replaces the pinch-pin™ when not in use to prevent injury. Removable screens on top of each scoop allow water to flow through as it descends. This lessens the frontal shock wave and reduces surface disturbance. Both screens are covered with neoprene rubber flaps that close during retrieval. Choose all stainless steel for severe conditions. Ship wt: 67 lbs. Crane and winch recommended due to working weight.

Sediment Analysis