1. 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

2. 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.

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

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

5. 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

6. 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 mg

7. 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)

8. 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

9. 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

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

11. 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

12. 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)

13. 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

14. 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.

15. 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

16. 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

17. 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

18. 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

19. NC Waters Average NTU’s Salt ~ 25 Fresh ~ 50

20. 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

21. 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.

22. Sediment Analysis