Fecal Bacteria

What is Fecal Bacteria?

Fecal bacteria are bacteria from animal (including human) waste or feces, and are measured as a concentration of most probable number (MPN/100mL) present in the water. MPN is a statistical method used to estimate the viable numbers of bacteria. Fecal bacteria are a diverse group of microorganisms, several of which are used for monitoring water. In this study, we measure the concentration of Enterococcus fecal bacteria, which can indicate potential sewage contamination and constitute a human health risk from water contact. Fecal bacteria enter waterways through stormwater runoff. Sources include animal waste, undisposed of pet waste, and sewage overflows of septic systems, sanitary sewer pipes, and wastewater treatment plants.

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Why is Fecal Bacteria important?

Enterococcus fecal bacteria are reliable indicators for waterborne pathogens that are excreted by mammals and humans. Including Staphylococcus, Hepatitis A, Cryptosporidium, West Nile Virus, and other microorganisms that may cause gastrointestinal illness and skin and eye infections. Risk factor makes collection of this data vital for assessing human health risk during recreational water contact.

How do we measure Fecal Bacteria?

Fecal bacteria are measured through collection of water samples at both tidal and nontidal stations and analyzed by our in house water quality laboratory. Nontidal stream samples are collected at the deepest point of moving water in the vicinity of our station, and away from riffles. Tidal samples are collected 1 meter from the surface. All samples are stored on ice, and delivered the same day to the Blue Water Baltimore Water Quality Laboratory. Samples are processed and analyzed in house. We assess Enterococcus fecal bacteria data using the Code of Maryland Regulation's (COMAR) pass/fail scale based on the <130 MPN/100mL human health thresholds for tidal and nontidal waters.

Chlorophyll α

What is Chlorophyll α?

Chlorophyll α is a type of green pigment, essential for photosynthesis, found in most algae and phytoplankton. Chlorophyll α is measured as a concentration in micrograms per liter (µg/L). Because Chlorophyll α is contained within algae, it can be used as an indicator for the amount of green-pigmented algae present in the water.

Why is Chlorophyll α important?

As an indicator for the amount of algae in waterways, Chlorophyll α is important for determining whether algal cells are present at ecologically healthy levels. When there is too much nutrient pollution (measured by Total Nitrogen and Total Phosphorus) present in the water, algae will rapidly reproduce and create visible blooms in the water. Sometimes these algal blooms are comprised of harmful species that secrete toxins which can stress or kill fish and other aquatic animals. When algae blooms die they are decomposed by bacteria that consume oxygen and cause a rapid decline in dissolved oxygen levels. These conditions can also stress or kill fish and other aquatic organisms. However, appropriate levels of Chlorophyll α are important to indicate that enough algae are present to serve as food for other aquatic creatures.

How do we measure Chlorophyll α?

We measure Chlorophyll α at tidal sampling sites using two different methods. First, using an optical probe lowered from our Waterkeeper boat the R/V Muckraker into the water at each station location, we collect readings at 0.25, 0.5 or 1.00 meter intervals from the water surface to just above the river bottom. Second, we collect a water sample from 1 meter below the water’s surface at each station, store samples on ice, and deliver samples the same day to the Blue Water Baltimore Water Quality Laboratory. Samples are processed in house and batch shipped to an outside laboratory for analysis. We assess Chlorophyll α data using a numeric pass/fail ecological threshold for mesohaline [https://encyclopedia2.thefreedictionary.com/mesohaline] systems of ≤6.2 µg/L in spring and ≤7.7 µg/L in summer, which was established by the Mid-Atlantic Tributary Assessment Coalition (MTAC) Sampling and data analysis protocols for Mid-Atlantic tidal tributary indictors.

Dissolved Oxygen

What is Dissolved Oxygen?

Dissolved Oxygen is the measure of the amount of oxygen present in the water and available to aquatic organisms. Dissolved Oxygen is measured both as a concentration in milligrams per liter (mg/L) and percent-saturation.  Which indicate the amount of oxygen water is capable of holding at any given temperature. Dissolved Oxygen enters tidal and nontidal streams and rivers through physical mixing at shallow stream riffles, man-made structures, and photosynthetic production by algae and aquatic plants.

Why is Dissolved Oxygen important?

Dissolved Oxygen is an essential element of survival for most aquatic life. Fin-fish and aquatic macroinvertebrate insects try to avoid areas of water containing low levels of Dissolved Oxygen, but can become trapped. When trapped in an area of low Dissolved Oxygen, aquatic life become stressed and die off. Some causes of low levels of Dissolved Oxygen can be decaying algal blooms being decomposed by bacteria and reactions during thermal inversion (water column inversion due to temperature). During thermal inversion, Sulfur bacteria rise to the surface of the water column and perform anoxic photosynthesis (photosynthesis without the production of oxygen) which uses up dissolved oxygen in the water.

How do we measure Dissolved Oxygen?

Dissolved Oxygen is measured at tidal sampling sites with an optical probe lowered from our Waterkeeper boat the R/V Muckraker, into the water at each station location. Dissolved Oxygen readings are automatically collected at 0.25, 0.5 or 1.00 meter intervals from the water’s surface to just above the river bottom. Dissolved Oxygen at nontidal stations is measured by placing a YSI Probe into the water, completely submerging the sensor. We assess Dissolved Oxygen data using the Code of Maryland Regulation's (COMAR) pass/fail scale of ≥5.0 mg/L.

pH

What is pH?

pH is a measurement of the concentration of hydrogen ions in the water. pH is measured on a logarithmic scale (0-14 pH units), with lower values considered acidic (high levels of H+ ions) and higher values considered basic (lower levels of H+ ions). The carbonate system is a natural process that maintains pH equilibrium in waters impacted by the photosynthesis and respiration of aquatic plants and decomposition by bacteria. Pollution from sewage overflows, stormwater runoff, carbon dioxide emissions, chemical spills and acid precipitation can negatively impact healthy pH levels.

Why is pH important?

Consistent and moderate levels of pH are critical for the survival of aquatic life. pH affects the availability of essential nutrients and minerals, and the presence of toxic substances in the water. Acidic waters (low pH) impede the ability of freshwater invertebrates to build their calcium carbonate shells. Low pH levels also increase the availability of phosphorus, driving algal blooms that can ultimately result in harmful decreases of dissolved oxygen. Basic waters (high pH) increase the availability of ammonia, which is toxic to aquatic life.

How do we measure pH?

pH is measured at tidal sampling sites with an optical probe lowered from our Waterkeeper boat the R/V Muckraker, into the water at each station location. pH readings are automatically collected at 0.25, 0.5 or 1.00  meter intervals from the water’s surface to just above the river bottom. pH at nontidal stations is measured by placing a YSI Probe into the water, completely submerging the sensor. We assess pH data using a numeric pass/fail threshold of 6.5 – 8.5 (SU pH), which was established by the Mid-Atlantic Tributary Assessment Coalition (MTAC) Sampling and data analysis protocols for Mid-Atlantic tidal and nontidal tributary indictors.

Phycoerythrin

What is Phycoerythrin?

Phycoerythrin is a red protein pigment found in some phytoplankton and algae, such as Cyanophyceae (Cyanobacteria) and Cryptophyceae. Phycoerythrin is measured as a concentration in cells per milliliter (cells/mL). Because Phycoerythrin is contained within Cyanophyceae, it can be used as an indicator for the amount of Cyanobacteria present in the water.

Why is Phycoerythrin important?

As an indicator for the amount of Cyanophyceae in waterways, Phycoerythrin is important for determining whether Cyanobacteria are present at ecologically healthy levels. When too much nutrient pollution, measured by Total Nitrogen and Total Phosphorus, is present in the water, Cyanobacteria will rapidly reproduce. The result being algal blooms comprised of potentially-harmful species that secrete toxins which, under some circumstances, may stress or kill fish and other aquatic animals. Less often, these toxins may also pose a risk to humans.

How do we measure Phycoerythrin?

Phycoerythrin is measured at tidal sampling sites with an optical probe lowered from our Waterkeeper boat the R/V Muckraker, into the water at each station location. Phycoerythrin readings are automatically collected at 0.25, 0.5 or 1.00 meter intervals from the water’s surface to just above the river bottom. We assess the Phycoerythrin data for readings collected above the pycnocline [https://en.wikipedia.org/wiki/Pycnocline] using the World Health Organization’s numeric human health pass/fail threshold of ≤20,000 cells/mL.

Salinity

What is Salinity?

Salinity is the measurement of the concentration of dissolved salts in the water. Salt compounds, which originate through erosion of rocks, include sodium chloride, magnesium sulfate, and sodium bicarbonate. When these compounds dissolve they become present as ions in the water. Salinity is affected by the relative input of freshwater. Inputs include freshwater streams and rivers and saltwater from the Chesapeake Bay and Atlantic Ocean. Salinity is measured in Parts Per Thousand (PPT) and can range from nearly 0 in freshwater to 35 in the open ocean.

Why is Salinity important?

Aquatic plants and animals are evolutionarily adapted to live in different levels of salinity. When salinity levels change and exceed acceptable ranges, organisms can be excluded from their habitat.

How do we measure Salinity?

Salinity is measured at tidal sampling sites with an optical probe lowered from our Waterkeeper boat the R/V Muckraker, into the water at each station location. Salinity readings are automatically collected at 0.25, 0.5 or 1.00 meter intervals from the water’s surface to just above the river bottom. The State of Maryland has not established an assessment threshold for Salinity, but we utilize our Salinity data to measure the pycnocline in the water column in order to assess Dissolved Oxygen data. 

Specific Conductance

What is SPECIFIC CONDUCTANCE?

Specific Conductance is the measurement of how well water conducts electricity through its content of ions and is measured in standard unit microSiemens per centimeter (µS/cm) at a water temperature of 25 degrees Celsius. Naturally occurring ions include calcium and magnesium, but urban streams and rivers are also subject to pollution from sewage overflows, industrial discharge, and stormwater runoff containing nitrate, phosphate, chloride, salt, and metals ions.

Why is SPECIFIC CONDUCTANCE important?

Elevated Specific Conductance can be an indicator of an unnatural or harmful imbalance of ion content in the water. Low levels of Specific Conductance may indicate a lack of elements essential for aquatic life, such as calcium and magnesium. A factor causing this can be pollution discharges containing noncharged ions, such as oil and phenols.

How do we measure SPECIFIC CONDUCTANCE?

Specific Conductance is measured at tidal sampling sites with an optical probe lowered from our Waterkeeper boat the R/V Muckraker, into the water at each station location. Specific Conductance readings are automatically collected at 0.25, 0.5 or 1.00 meter intervals from the water’s surface to just above the river bottom.  Specific Conductance at nontidal stations is measured by placing a YSI Probe into the water, completely submerging the sensor. We assess Specific Conductance data using a numeric pass/fail threshold of ≤100 µS/cm for tidal streams which was established by the Mid-Atlantic Tributary Assessment Coalition (MTAC) Sampling and data analysis protocols for Mid-Atlantic tidal tributary indictors. The State of Maryland has not established an assessment threshold for Specific Conductance in nontidal streams.

Temperature

What is Temperature?

Water Temperature is the measurement of heat energy in water. Scientific applications typically record Temperature in degrees Celsius. Many factors affect Temperature including ambient air Temperature, water velocity and volume, inputs from runoff, and other natural and human sources of physical, biological, and chemical thermal pollution.

Why is Temperature important?

Aquatic plants and animals are evolutionarily adapted to live in specific Temperature ranges with seasonal variations. When water Temperature exceeds the acceptable range for a given organism, that organism may die, become stressed, or become excluded from their habitat. Other critical water-quality parameters, such as Dissolved Oxygen, are dependent on Temperature.

How do we measure Temperature?

Temperature is measured at tidal sampling sites with an optical probe lowered from our Waterkeeper boat the R/V Muckraker, into the water at each station location. Temperature readings are automatically collected at 0.25, 0.5 or 1.00 meter intervals from the water’s surface to just above the river bottom. Temperature at nontidal stations is measured by placing a YSI Probe into the water, completely submerging the sensor. We assess Temperature data using the Code of Maryland Regulation's (COMAR) pass/fail scale of ≤32°C (Use Class I & II waters), ≤20°C (Use Class III waters), ≤23.9°C (Use Class IV waters). COMAR defined use classes are listed below and ensure ecological health of aquatic ecosystems in Maryland waters.

Class I Waters — Water Contact Recreation and Protection of Nontidal Warmwater Aquatic Life.

Class II Waters — Support of Estuarine and Marine Aquatic Life and Shellfish Harvesting.

Class III Waters — Nontidal Cold Water.

Class IV Waters — Recreational Trout Waters.

http://www.dsd.state.md.us/comar/comarhtml/26/26.08.02.03-3.htm

Total Nitrogen

What is Total Nitrogen?

Total Nitrogen is a measurement of how much elemental nitrogen in various molecular forms is present in the water. Total Nitrogen is measured as a concentration in milligrams per liter (mg/L). Nitrogen enters waterbodies from organisms that naturally live in and around the water and through discharges of various sources of water pollution. Pollution may include sewage overflows, industrial discharges, and stormwater runoff containing animal waste, fertilizers, any other nitrogen-rich substances.

Why is Total Nitrogen important?

Nitrogen is an essential element for cellular formation of plant, bacteria and animal life. Nitrogen is the most limiting nutrient in saltwater systems. This means when nitrogen is added to a saltwater system, rapid algal cell growth often occurs. This creates an algal bloom and can have serious impacts on aquatic and human life. Some species of algae secrete toxins that can stress or kill aquatic and terrestrial animals. When toxic and nontoxic algae die, they are decomposed by bacteria that consume oxygen, causing a rapid decline in dissolved oxygen levels in the water column. These conditions stress or kill fish and other aquatic organisms. Excess levels of nitrogen are often input directly, or discharge from upstream, to receiving tidal salt or brackish waters and can cause limited dissolved oxygen zones, referred to as "dead zones" by the mechanism explained above.

How do we measure Total Nitrogen?

Total Nitrogen is measured through the collection of water samples at both tidal and nontidal stations for analysis by an outside laboratory. Nontidal stream samples are collected at the deepest point of moving water in the vicinity of our station, and away from riffles. Tidal samples are collected 1 meter from the surface. All samples are stored on ice, and delivered the same day to the Blue Water Baltimore Water Quality Laboratory where they are frozen. Samples are batch shipped to an outside laboratory for analysis. We assess the Total Nitrogen data using a numeric pass/fail threshold for mesohaline [https://encyclopedia2.thefreedictionary.com/mesohaline] tidal systems of ≤0.6 mg/L. For nontidal systems we use ≤1.65 mg/L for piedmont nontidal streams and ≤1.52 mg/L for coastal plain nontidal streams which was established by the Mid-Atlantic Tributary Assessment Coalition (MTAC) Sampling and data analysis protocols for Mid-Atlantic tidal and nontidal tributary indictors.

Total Phosphorus

What is Total Phosphorus?

Total Phosphorus is a measurement of how much elemental phosphorus in various molecular forms is present in the water. Total Phosphorus is measured as a concentration in milligrams per liter (mg/L). Phosphorus enters waterbodies through discharges of various sources of water pollution. Pollution may include sewage overflows, industrial discharges, and stormwater runoff containing animal waste, fertilizers, and other phosphorus-rich substances.

Why is Total Phosphorus important?

Phosphorus is an essential element for cellular formation of plant, bacteria and animal life. Phosphorus is the most limiting nutrient in freshwater systems. This means when phosphorus is added to a freshwater system, rapid algal cell growth often occurs. This creates an algal bloom and can have serious impacts on aquatic and human life. Some species of algae secrete toxins that can stress or kill aquatic and terrestrial animals. When toxic and nontoxic algae die, they are decomposed by bacteria that consume oxygen, causing a rapid decline in dissolved oxygen levels in the water column. These conditions stress or kill fish and other aquatic organisms. Excess levels of phosphorus are often input directly, or discharge from upstream, to receiving fresh waters and can cause limited dissolved oxygen zones, referred to as "dead zones" by the mechanism explained above.

How do we measure Total Phosphorus?

Total Phosphorus is measured through the collection of water samples at both tidal and nontidal stations for analysis by an outside laboratory. Nontidal stream samples are collected at the deepest point of moving water in the vicinity of our station, and away from riffles. Tidal samples are collected 1 meter from the surface. All samples are stored on ice, and delivered the same day to the Blue Water Baltimore Water Quality Laboratory where they are frozen. Samples are batch shipped to an outside laboratory for analysis. We assess the Total Phosphorus data using a numeric pass/fail threshold for mesohaline [https://encyclopedia2.thefreedictionary.com/mesohaline] tidal systems of ≤0.04 mg/L. For nontidal systems we use ≤0.03 mg/L for piedmont nontidal streams and ≤0.06 mg/L for coastal plain nontidal streams which was established by the Mid-Atlantic Tributary Assessment Coalition (MTAC) Sampling and data analysis protocols for Mid-Atlantic tidal and nontidal tributary indictors.

Turbidity

What is Turbidity?

Turbidity is the measurement of how much light can penetrate through the water. Turbidity is measured in Nephelometric Turbidity Units (NTU) and is an indicator of the amount of particles including sediment and phytoplankton, are suspended in the water.

Why is Turbidity important?

Low Turbidity levels are important for the survival of aquatic plants and animals. Low levels of Turbidity allow sunlight to reach aquatic plants, enabling critical fish-habitat forming plants to photosynthesize. Low levels of Turbidity also indicate low levels of suspended solid particles including algae, sediment (silt and clay), and other pollutants. Particles that may otherwise interfere with the ability of aquatic animals to respire (breathe) and locate crucial food and habitat. Increased Turbidity levels often indicate high levels of sediment pollution. Sediment settles on the bottoms of water bodies and smothers stream macroinvertebrate insects and fish spawning habitat.

How do we measure Turbidity?

Turbidity is measured using a portable field instrument capable of analyzing water samples. Nontidal stream samples are collected at the deepest point of moving water in the vicinity of our station, and away from riffles, and analyzed with the field instrument. We assess the Turbidity data using a numeric pass/fail threshold of ≤4.75 NTUs which was established by the Mid-Atlantic Tributary Assessment Coalition (MTAC) Sampling and data analysis protocols for Mid-Atlantic nontidal tributary indictors.

Water Clarity

What is Water Clarity?

Water Clarity is the measurement of how much sunlight can penetrate through the water. Water Clarity is measured as a distance in decimeter units (dm) from the water’s surface to the depth where sunlight can no longer penetrate the water. Water Clarity is diminished when solid particles like dirt and algae are suspended in the water column and absorb or reflect sunlight.

Why is Water Clarity important?

High water clarity is important for the survival of aquatic plants and animals. High water clarity allow sunlight to reach aquatic plants, enabling critical fish-habitat forming plants like bay grasses to photosynthesize. High water clarity also indicate low levels of suspended solid particles including algae, sediment (silt and clay), and other pollutants. Particles that may otherwise interfere with the ability of aquatic animals to respire (breathe) and locate crucial food and habitat.

How do we measure Water Clarity?

Tidal Water Clarity is measured using an instrument called a Secchi Disk. The black-and-white colored weighted disk is attached to a graduated line and lowered into the water until the point where the disk is no longer visible. The disk is raised and lowered several times to ‘zero in’ on the depth where the disk becomes invisible and visible. The midpoint of these two depths is recorded as the Secchi depth. If the Secchi disk is still visible on the bottom, the Secchi depth is recorded as the water depth and noted. We assess Water Clarity data using a numeric pass/fail threshold of ≥1.6 dm which was established by the Mid-Atlantic Tributary Assessment Coalition (MTAC) Sampling and data analysis protocols for Mid-Atlantic tidal tributary indictors.