WHAT IS IT:Temperature is a measure of the average energy (kinetic) of water molecules. It is measured on a linear scale of degrees Celsius or degrees Fahrenheit.It can change moderately within a day as a result of tides, current, surface heating. In the NY Harbor it changes significantly across seasons (35F to 75F). Temp at any given time and range over time is dependent on depth; the surface layer is always the warmest and has the widest range. The deeper the water the more likely the temperature will remain steady. The mean depth of the HMP is 6 ft. therefore the temperature measured on the platform will be closely

WHY IS IT IMPORTANT:• Water Temperature is a controlling factor for all aquatic life. It controls the rate of

metabolic activities, reproductive activities, rate of photosynthesis by algae and other aquatic plants, sensitivity to disease and toxicity, timing of aestivation (dormancy or hibernation), and life cycles in general. If water temperatures increase, decrease or fluctuate too widely, metabolic and reproductive activities may speed up, slow down, malfunction, or stop altogether.

• Temperature also directly controls the potential concentration of dissolved oxygen in a water body. Oxygen is more easily dissolved in cold water; therefore the lower the water temperature the more potential dissolved oxygen. For example, fresh water at 0°C can contain up to 14.6 mg of oxygen per liter of water, but at 20°C, it can only hold 9.2 mg of oxygen per liter.

• It is a general rule that the more oxygen there is in the water, the healthier the estuary is, especially when the water temperature is warmer.

RANGE:Extreme low: 30oF (saline water has a lower freezing point than fresh water)Average seasonal range: 35-75oFTolerance level for oysters: 28 to 85oF (?)Ideal range for oyster growth in NY harbor: 65-75oF (?) *bacterial diseases affecting oysters may be more likely to occur in warmer waters, therefore even though oysters grow faster in warmer waters it may be dangerous if temp rises above 75oF for a prolonged period (>week)Record high in NY Harbor (Battery): (?)

USEFUL LINKS:NOAA Marine Station: http://tidesandcurrents.noaa.gov/stationhome.html?id=8518750Text adapted from:http://www.dnr.mo.gov/env/esp/waterquality-parameters.htm#Temperature

SAMPLE IMAGES:

Water Temperature

WHAT IS IT:pH is a measure of how acidic or basic (alkaline) the water is. pH is measured by a numeric scale with a range of 0 to 14. Solutions with a pH of less than 7 are acidic, and those with a pH greater than 7 are basic (or alkaline). Distilled water is neutral and has a pH of 7.(The term pH comes from the French: "puissance d'Hydrogène" which means strength of the hydrogen. It is defined as the negative log of the hydrogen ion concentration. The pH scale is logarithmic. For each whole number increase (i.e. 1 to 2) the hydrogen ion concentration decreases ten fold and the water becomes less acidic.)

WHY IS IT IMPORTANT:• The essential biochemical reactions of aquatic organisms, such as cellular

metabolism, require a narrow pH range. If solutions in the internal or external environment of an organism have pH outside the required range then the organism may become sick and die.

• Most aquatic organisms are adapted to live in solutions with a pH between 5.0 and 9.0.

• The pH of an estuary tends to remain constant (around 6.5) because the chemical components in seawater resist large changes to pH. Biological activity, however, may significantly alter pH in an estuary.

• Through photosynthesis, plants remove carbon dioxide (CO2) from the water and expel oxygen (O2). Since CO2 becomes carbonic acid when it dissolves in water, the removal of CO2 results in a higher pH, and the water becomes more alkaline, or basic. When algae naturally begin to increase in estuaries during the spring, pH levels tend to rise. An overabundance of algae (called an algal bloom) may cause pH levels in an estuary to rise significantly, and this can be lethal to aquatic animals.

• At the extreme ends of the pH scale, (2 or 13) physical damage to gills, exoskeleton, fins, occurs.

• Changes in pH may alter the concentrations of other substances in water to a more toxic form. For example: a decrease in pH (below 6) may increase the amount of mercury soluble in water. An increase in pH (above 8.5) enhances the conversion of nontoxic ammonia (ammonium ion) to a toxic form of ammonia (un-ionized ammonia).

RANGE:

pH

Total range: 0-14.0Tolerance level for all aquatic life: 5.0 to 9.0Tolerance level for oysters: 6.5 to 9.0

Useful Links:http://www.arroyoseco.org/wqparameters.htm http://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar10f_ph.html

Sample Images:

WHAT IS IT:Dissolved Oxygen is the measure of the concentration of oxygen gas in water. A concentration is the weight or mass of a particular substance per a given volume of liquid. DO is the mass of oxygen gas present in a given sample of the estuary, usually expressed in milligrams per liter of water. Milligrams per liter, or mg/L, can also be expressed as parts per million, or ppm.

Oxygen enters the water through two natural processes: (1) diffusion from the atmosphere and (2) photosynthesis by aquatic plants. The mixing of surface waters by wind and waves increases the rate at which oxygen from the air can be dissolved or absorbed into the water.

DO levels are also influenced by temperature and salinity. The solubility of oxygen, or its ability to dissolve in water, decreases as water temperature and salinity increase. DO levels in an estuary also vary seasonally, with the lowest levels occurring during the late summer months when temperatures are highest.

WHY IT’S IMPORTANT:

Dissolved Oxygen

• To survive, fish, crabs, oysters and other aquatic animals must have sufficient levels of dissolved oxygen (DO) in the water. The amount of dissolved oxygen in an estuary’s water is the major factor that determines the type and abundance of organisms that can live there.

• Bacteria, fungi, and other decomposer organisms reduce DO levels in estuaries because they consume oxygen while breaking down organic matter. 

• Oxygen depletion may occur in estuaries when many plants die and decompose, or when wastewater with large amounts of nitrogen or other organic material enters the estuary. In some estuaries, large nutrient inputs, typically from sewage, stimulate algal blooms. When the algae die, they begin to decompose. The process of decomposition depletes the surrounding water of oxygen and, in severe cases, leads to hypoxic (very low oxygen) conditions that kill aquatic animals. Shallow, well-mixed estuaries are less susceptible to this phenomenon because wave action and circulation patterns supply the waters with plentiful oxygen.

• From mid July through September some areas of NY Harbor such as Jamaica Bay suffer from hypoxia. During this period, oxygen levels at the bottom levels of the Harbor fall to levels inadequate to support healthy populations of aquatic life. Summer hypoxia is caused by a combination of warm temperatures (limiting oxygen solubility) and excessive nitrogen loading in the Harbor from sewer outfalls and treated effluent (more than 200,000 lbs. per day!)

• Additional Causes of Low D.O.o Removal of riparian vegetation may lower oxygen concentrations due to

increased water temperature resulting from a lack of canopy shade and increased suspended solids resulting from erosion of bare soil.

o Urban runoff bearing salts, sediments and other pollutants increases the amount of suspended and dissolved solids, which may lead to lower D.O.

o Channelizing or dredging may pose an oxygen supply problem. Although deeper water is cooler, it may be low in oxygen if large amounts of organic matter has fallen to the bottom and has been decomposed by bacteria.

TOLERANCE LEVELS:See charts below...3.0 mg/l is considered the lower limit for fish survival by NYC DEC and US EPAAnything below 2.0 mg/l will result in lethal effects for most aquatic lifeWorms and other bottom dwelling invertebrates can tolerate levels as low as 1.0Oysters needs at least 4.5 mg/l to survive and grow

USEFUL LINKS:

SAMPLE IMAGES:

WHAT IS IT:Salinity is the concentration of salt in water, usually measured in parts per thousand (ppt). The salinity of seawater in the open ocean is remarkably constant at about 35 ppt. Salinity in an estuary varies according to one's location in the estuary, the daily tides, and the volume of fresh water flowing into the estuary.

In estuaries, salinity levels are generally highest near the mouth of a river where the ocean water enters, and lowest upstream where freshwater flows in. Actual salinities vary throughout the tidal cycle, however. Salinity levels in estuaries typically decline in the spring when snowmelt and rain increase the freshwater flow from streams and groundwater. Salinity levels usually rise during the summer when higher temperatures increase levels of evaporation in the estuary.

WHY IT’S IMPORTANT:• Estuarine organisms have different tolerances and responses to salinity changes.

Many bottom-dwelling animals, like oysters and crabs, can tolerate some change in salinity, but salinities outside an acceptable range will negatively affect their growth and reproduction, and ultimately, their survival.

• Salinity also affects chemical conditions within the estuary, particularly levels of dissolved oxygen in the water. The amount of oxygen that can dissolve in water, or solubility, decreases as salinity increases. The solubility of oxygen in seawater is about 20 percent less than it is in fresh water at the same temperature.

Salinity

• In an estuary, where salt and fresh water meet, salinity is generally higher and more stable at the bottom depths. This allows organisms that have a higher salinity preference to remain at the bottom depths as they migrate through the harbor. Oysters generally prefer the middle to upper levels of the water column due to lower salinity, higher DO, and more consistent nutrient flow.

TOLERANCE LEVELS:• Oysters’ salinity tolerance range is relatively wide. Generally below 5 is deadly, 5

to 7.5• They can tolerate brackish water with salinity as low as 5 parts per thousand

(ppt) all the way up to full strength seawater (at 35 ppt salinity) BUT their growth rates will be extremely limited in particularly in the lowest extremes.

• Eastern oysters (c. virginica) cannot survive for more than a few hours in water with salinity less than 5 ppt. Their ideal range is somewhere right in the middle (around 15 to 20 ppt) but their specific preferences and adaptations depend on the local habitat and water body in which the oyster lives.

• In the Upper Bay of the New York Harbor, the salinity varies from as low as 10 ppt around the George Washington Bridge to as high as 30 near the Verrazano.

• EXO2 does not have a salinity specific sensor but calculates it through conductivity and temperature

LINKS:http://hudson.dl.stevens-tech.edu/maritimeforecast/maincontrol.shtml http://www.floridaocean.org/uploads/files/Research/Water%20Quality/131212.pdf

SAMPLE IMAGES:

Turbidity, Total Solids (Suspended or Dissolved), and

WHAT IS IT:These three parameters are related:

• Turbidity is a measure of the cloudiness (opacity) of water. Cloudiness is caused by suspended solids (mainly soil particles) and plankton (microscopic plants and animals) that are suspended in the water column.

• Total Solids is a measure of the quantity (usually in grams or milligrams per liter) of all types of solids in a body of water (either dissolved or suspended).

• Conductivity is a measure of how well water can pass an electrical current. It is an indirect measure of the composition of total dissolved solids (TDS) or total suspended solids (TSS) including inorganic dissolved solids such as chloride, nitrate, sulfate, phosphate, sodium, magnesium, calcium, iron and aluminum versus organic substances like oil, alcohol, and sugar. The presence of inorganics increases the conductivity of a body of water while organics general decrease conductivity.

WHY IT’S IMPORTANT:Turbidity is an indirect measurement of how much light can penetrate to the deeper levels of the Harbor. Moderately low levels of turbidity may indicate a healthy, well-functioning ecosystem, with moderate amounts of plankton present to fuel the fuel the food chain. However, higher levels of turbidity pose several problems for the estuary. Turbidity blocks out the light needed by submerged aquatic vegetation. It also can raise surface water temperatures above normal because suspended particles near the surface facilitate the absorption of heat from sunlight.

Oysters are adapted to live in a wide range of sedimentary conditions, as is the nature of an estuary. Total suspended solids may include abundant algae (oyster food), however too much suspended solids (consisting of soil particles, nutrients, and contaminants) can inhibit or block oyster growth altogether.

Turbid waters may also be low in dissolved oxygen. High turbidity may result from sediment bearing runoff, or nutrients inputs that cause plankton blooms. Once the sediment settles, it can foul gravel beds and smother fish eggs and benthic insects. Extreme high levels of TDS may also clog fish gills.

Range and Tolerance Level: • In general estuaries have a very wide range of turbidity and TSS. The highest

turbidity and TDS levels in NY Harbor are found in the Upper Bay and lower Hudson where currents mix and salt water meets sediment bearing fresh water.

• Oysters are adapted to live in a wide range of sedimentary conditions, as is the nature of an estuary. Total suspended solids may include abundant algae (oyster food), however too much suspended solids (consisting of soil particles, nutrients, and contaminants) can inhibit or block oyster growth altogether. Extreme highs and extreme lows are generally not good.

• TSS tolerance level for adult oyster survival is unknown but Kennedy et al estimate .25 grams per liter (dry weight) to be the maximum for survival of eggs and .5 g/l for survival of larvae.

• Generally anything above .5 G/L TSS should be considered detrimental to oyster growth.

• EXO2 calculates TSS and TDS in mg/L. The range for TSS is 0 to 1500 mg/L and for TDS 0 to 100,000 G/L.

• EXO2 calculates turbidity in FNU or Formazin Nephelometric Units. FNU is essentially the degree to which light is scattered by particles suspended in a liquid; however scattering depends on the angle of the beam applied and the type of light source. In the case of FNU the angle is 90 degrees and the light source is infrared.

• The full FNU range in the EXO2 is 0 to 4000 FNU• Typical estuarine range in FNU is (?)

WHAT IS IT:Chlorophyll is a green pigment in plants that turns light energy into food and allows plants to grow, and releases oxygen in a process called photosynthesis. The microscopic one-celled plants (algae) that float in healthy waters are called phytoplankton. Chlorophyll is an indicator of the prevalence of phytoplankton.

WHY IT’S IMPORTANT: • Tracking chlorophyll over time gives us an understanding of the range of

phytoplankton levels in our estuary. We can track and try to understand the causes for detrimental algal blooms (identified by extreme high levels of chlorophyll) and smaller fluctuations caused by natural ecological changes, weather events, runoff, and sewage discharges.

• By measuring the amount of chlorophyll in the water, we can determine the density of phytoplankton in an estuary and the amount of primary productivity (the conversion of light energy into plant material).

• Phytoplankton forms the base of the aquatic food web in an estuary. It is eaten by zooplankton (microscopic animals) and small fish, which, in turn, are eaten by larger creatures. The abundance of healthy animals in an estuary often depends on the amount of phytoplankton and primary productivity taking place.

• Phytoplankton is oyster food. The main classes of Phytoplankton that oysters eat are Diatoms, Dinoflagelates, Coccolithophorids and Micro-Flagellates. Of these there are hundreds of genera and hundreds of thousands of species. Oysters like a varied diet of species from all classes.

• As an element of total dissolved solids, chlorophyll content upstream and downstream from an oyster restoration site can give us an estimate of how much suspended sediment including phytoplankton oysters are removing from the water column.

RANGE AND LEVELS• EXO2 measures chlorophyll in μg/L (micrograms per liter). The total range is 0 to 400• Typical estuarine range in μg/L is (?)

Chlorophyll

Source: University of Maryland, Kennedy et al 2006

Source: YSI EXO2 Technical Manual

I. SonTec XR Argonaut Current Profiler

WHAT IS IT:The current profile is the velocity and direction of the water column measured at specific increments (also called cells) from the seafloor to the surface. The current profiling instrument on the science platform is the SonTec XR Argonaut.

The SonTec XR has a total range of 6 meters and 10 cells plus one dynamic (auto adjusting) cell. Each cell has a minimum size of .2 meters therefore we can measure the current at 11 levels at least .2 m apart.

The XR automatically adjusts with the changing tide (total depth) so that one cell is continuously profiling just below the surface while the other ten cells can be set at constant depth from the seafloor.

The depth range at the GI reef site is approximately 6 to 15 feet depending on tide and location within the (downward sloping) footprint of the reef.

The range of water velocity and direction currently estimated at the reef site is:0 to 2kts (0 to 1 m/s and 0 to 2.25 mph) using Stevens Institute NYHOPS modeling system.

Water Velocity and Direction

WHY IT’S IMPORTANT:We expect the installation of the reef to have an attenuating effect on tidal current on and around the site. We plan to place the current profiler just behind (shoreward) the reef structures. We plan to install the XR at least one month prior to the installation of the reef structures in order to collect sufficient (baseline) data. These data will help to explain the predominant current patterns prior to the installation of the reef. With this baseline we will be able to compare the impacts of installing the oyster reef. The reef structures will be installed in components starting in June 2014 with full build-out expected to be completed by October of 2014.

The other important reason for continuous profiling of the current at the GI reef site is site safety. Regardless of potential attenuating effects of the reef structure, divers and vessel operators need real time current information prior to and during operations on the site. This information will help them make better informed decisions about site safety, manuervability and dive logistics. In the absence of current profiling we use slack tide as the best predictor of when it’s safe to dive. Having real time velocity and direction data will allow divers and vessel operators to expand operations beyond the short 1.5 hour window typically created by slack tide.

The XR also measures depth up to a max of 20 feet. The dashboard will continuously display the total depth reading on site. Divers and vessel operators will compare real time depth with predicted tides and use the total information to assess site safety and logistics. Up to date tides and water levels for the battery can be found at the NOAA monitoring station dashboard: http://tidesandcurrents.noaa.gov/stationhome.html?id=8518750

II. External Eventsa. Externally measured WQ parameters

i. Total Nitrogen, Phosphate, Ammonia

These are key nutrients affecting the health of the estuary. Total nitrogen is usually in excess in NY Harbor due to sewer outfalls and other urban impacts. Phosphate is typically a limiting nutrient though it too can occur in excess as a result of upstream agricultural activities as well as sewer outfalls. Ammonia is typically the result of anoxic conditions and is highly toxic to aquatic life in concentrations higher than ______

Technology does not exist to measure these parameters in real time in saline water bodies. Harbor School marine biology research students do measure these parameters by hand (using chemical solutions) at a max frequency of twice monthly. The data for these measurements can be found at https://docs.google.com/spreadsheet/pub?key=0AjkpjB8fZIOIdGZYRFRtRGl3M01fSUM0b2UxejJULXc&output=html

Nutrient measurements will be considered external events and graphed as color coded single points along the continuous lines of the real time parameters measured by the

Tides and Depth

EXO2. Externally collected nutrient parameters could also be displayed separately in their own gauges on the dashboard; however because of the infrequency of these measurements the readings will only be of interest in relationship to the real time parameters.

ii. Bacteria – Enterococcus Enterococcus is a fecal coliform bacteria occurring in high concentrations in human waste. When high levels or sudden spikes in enterroccocus are found in NY Harbor the cause is generally sewage outfalls. In NYC stormwater runoff from the street is not separated from household waste. In dry weather this system works fine however in a rain event the entire combined volume must be treated by wastewater treatment plants. NYC’s 16 wastewater treatment plants have a combined capacity of 1.7 billion gallons per day. On average 1.4 billion gallons of fresh water flows into the five boroughs everyday from the upstate reservoir system. The remaining 300 million gallons is essentially excess capacity for stormwater runoff. A rain event of .25 inches fallen across the city in 24 hours or less amounts to approximately 300 million gallons of total runoff; therefore whenever it rains a quarter inch or more in 24 hours the city’s combined sewer system will overflow in one or more locations.

Low levels of fecal coliform occur naturally in the estuary; and high levels do not necessarily pose an acute risk for aquatic life. The concern around fecal coliform is largely an issue for HUMAN health. Presence of high levels of fecal coliform is a concern by itself and can make people sick if they are directly exposed to it, but it is also a strong predictor of the presence of other forms of bacterial and viral pathogens spread by untreated sewage. (e. coli and others?)

The original cause for the closure of NY Harbor shellfisheries was precisely this concern over the spread of fecal pathogens such as cholera and typhoid fever. Consumption of shellfish and swimming are two of the most common ways of exposing oneself to this risk.

*For the safety of SCUBA divers and others interacting directly with the Harbor enterococcus levels are the single most important factor in determining whether Harbor water is safe for swimming.

The Harbor School marine biology program monitors for enterococcus using the Enterolert system. Harbor water is collected in sterile containers and placed in a specialized incubator for 48 hours after which the samples are analyzed under a microscope. Currently the MBR program conducts the Enterolert test twice per month.

The Enterolert data will be uploaded to the dashboard and displayed alongside the EXO2 parameters and nutrient tests to provide a complete picture of the water quality of the Buttermilk Channel.

b. Meteorological Data

i. Rainfall – this is the prime cause for sewage overflow events.

ii. Wind speed – this can affect DO levels

iii. Barometric pressure

Other Types of External Events: These can be any incidents that we believe have an effect over water quality or the general health of the estuary. The ideal would be to graph events that have direct correlations with WQ changes as measured by the HMP: ie immediately after a major rainfall or spring warming event HMP salinity drops markedly. Or immediately after a wastewater treatment plant experiences a prolonged shutdown, HMP chlorophyll levels spikes. Some examples of external events are:

1. Placement of new reef structures around the HMP site2. Placement of additional organisms or beginning of experiments at the HMP site

3. Major Weather events including rainfall, wind, heat, or snowfall events (with road salting)

4. Infrastructure improvements or major construction projects

5. Infrastructure failures ie malfunction of a wastewater treatment plant

6. Policy changes ie Clean Water Act of 1972

7. Point source pollution events ie oil spill

8. NYC DEP water quality alerts or data uploads

9. NYC Water trails data