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Great Lakes Water Quality


The Great Lakes Water Quality program at GLERL and the Cooperative Institute for Limnology and Ecosystems Research (CILER) is focused on understanding human health effects in the Great Lakes related to three research priority areas: beach closures, drinking water quality, and harmful algal blooms. Understanding ecosystem processes, particularly hydrodynamics and the influence of abiotic factors on the fate and transport of sources and loadings of bacteria and microbial contaminants, will ultimately lead to sound environmental decision-making and reduce human health risks. There are many processes and events that can influence sources, transport, and loading of bacteria and nutrients to the lakes, such as land-use and meteorological processes. Our research will improve forecasts of water quality to reduce risks to human health associated with recreational exposure and human consumption of Great Lakes water. Effective management of coastal ecosystems requires timely and continuing predictions of ecosystem change.

Pictured above clockwise from left: Harmful algal bloom in western Lake Erie, August 4, 2014; Rock bass. Grand Traverse Bay, Lake Michigan, 2007; MODIS satellite image. Lake Erie, March 11, 2012; Processing samples at the NOAA Great Lakes Environmental Research Lab in Ann Arbor, MI, June 26, 2014; Metro Beach on Lake St. Clair, June 16, 2014; Sampling harmful algal bloom in western Lake Erie, August 4, 2014. Credit: NOAA

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Harmful Algal Blooms

enviroTiggers zebraLink esp microcystinLink trackerLink

GLERL and CILER researchers are working to identify factors that influence harmful algal blooms (HABs) and to develop methods to forecast toxic cyanobacteria blooms. Research is focused on improving our ability to predict when algal blooms will occur, whether or not they are toxic, and their impact on human health. Field monitoring and observations collected by GLERL researchers keep track of nutrients at six master stations and two fixed moorings in western Lake Erie. The information gained from the field monitoring and observation assists in the development of probabilistic models for Lake Erie, which will be used to predict the magnitude of algal blooms while taking into account seasonal factors. GLERL and CILER's research and models support NOAA's National Centers for Coastal Ocean Science in monitoring and forecasting these harmful blooms through the the Harmful Algal Bloom Bulletin.

Harmful Algal Blooms in Lake Erie- Experimental HAB Bulletin

Lake Erie HAB Bulletin E-Mail Sign Up

An experimental HAB bulletin has been developed to provide a weekly forecast for Microcystis blooms in western Lake Erie. When a harmful bloom is detected by the experimental system, scientists will issue the forecast bulletin below. The bulletin depicts the HABs’ current location and future movement, as well as categorizes its intensity on a weekly basis.

Most recently updated Experimental Lake Erie HAB Bulletin

Latest Bulletin (.pdf)


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Hypoxia Warning System


Pictured: Dissolved oxygen concentrations (mg/l) in Lake Erie during September 7-11, 2005. Sampling stations are denoted with black dots. Note the large area of bottom hypoxia (i.e., dissolved oxygen levels < 4 mg/l) in the central basin, which can be stressful to fish. The thickness of this low-oxygen layer ranged from 1 to 5 m above the lake bottom (surface waters had sufficient oxygen). Data were collected as part of the IFYLE program, coordinated by scientists at NOAA's Great Lakes Environmental Research Laboratory (GLERL) in Ann Arbor, Michigan.

The Lake Erie ecosystem faces wide and varied threats to its health and integrity, including recurring low oxygen episodes ('dead zones') in the central basin. A prominent feature of Lake Erie's central basin is the lake bottom area of severe hypoxia ( < 2-3 ppm dissolved oxygen concentration) that recurs annually during late summer. Although the size of the dead zone declined with reduced phosphorus inputs during the mid-1980s, current levels of oxygen depletion are on par with those observed during the preceding period of severe cultural eutrophication, which is of concern to both Lake Erie resource management agencies and user groups.

Lake Erie Hypoxia Warning System (Click to view)

The Hypoxia Warning System is intended to combine observed data and forecasted surface currents to provide Lake Erie central basin drinking water managers information about the transport of hypoxic water into water intakes. The objectives of the project are to understand the chemistry and biology surrounding the microbial-driven formation of hypoxia and subsequently provide warnings of water chemistry changes, upwelling events and internal waves impacting drinking water quality at Cleveland, OH.

The Cleveland Water Department (CWD) provides drinking water to approximately 1.5 million people in 72 communities in Northeast Ohio. The water system gets its source water from the Lake Erie central basin through four water intakes covering approximately 27 miles of shoreline in the greater Cleveland area. Water treatment plants can be exposed to hypoxic waters (oxygen depleted) from Lake Erie, compromising water quality in the system (Ruberg, et al.). Hypoxic waters are low in pH and temperature, negatively impacting water treatment and subsequently drinking water quality. Low oxygen conditions also result in an increase in anaerobic bacteria that contribute high levels of manganese and iron to the hypolimnion (bottom water layer), leading to drinking water taste and odor problems. When hypoxic water reaches CWD intakes, pre-treatment operations are disrupted, and corrosion control strategies are affected by changes in temperature and pH. In addition, reduced and dissolved forms of iron and manganese from the hypolimnion enter the distribution system resulting in numerous customer water quality complaints about discolored water.

Ruberg S, E Guasp, N Hawley, R Muzzi, S Brandt, H Vanderploeg, J Lane, T Miller, S Constant. (Fall 2008). Societal Benefits of the Real-time Coastal Observation Network (ReCON): Implications for Municipal Drinking Water Safety. Marine Technology Society Journal 42:3:103-109

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Beach Water Quality

One of the main projects being done at GLERL and CILER is nearshore watershed modeling, with linkages to hydrodynamic modeling used to develop a framework for the fate and transport of bacteria in Lake Erie using information about surface currents, water levels, wind speeds, and water temperature. The nearshore water quality model is intended to assist in the prediction of levels of E. coli as it is dependent on the watershed, which is the amount of bacterial accumulation that is attributed to bacteria present on land. This project incorporates data gathered from the field observation and monitoring project. These data aid in calibration and adjustment of the model to have the best accuracy in predicting future E. coli concentrations, which becomes even more important during and after a storm event. As a result, the nearshore water quality model uses what is called a "linked model" type, which uses few calibrated parameters and is working in conjunction with the watershed model to determine the effects of runoff and bacterial load from the Clinton River into Lake St. Clair. The watershed model characterizes the deposition, decay, and accumulation of bacteria on the landscape and is important in predicting the source of bacterial loading.

When a storm event occurs, the bacteria that have accumulated on land due to a variety of sources, including both manmade and natural sources, can easily become part of the runoff that becomes part of the river and near shore environment, ultimately resulting in a drastic change in E. coli levels. The nearshore water quality model is used to understand how this bacterial loading changes over a given period of time, when the most loading occurs, and how long the high bacterial concentrations last after a storm event.

For the latest information on swimming advisories and closures in the Great Lakes, please contact your local public health authority. For supplemental information please see Great Lakes BeachCast.

Current Projects

(Click on items to reveal descriptions)

Great Lakes Beach, Tributary, and Near-shore Water Quality: Hydrologic and Hydrodynamic Data and Model Assimilation

  

Team: Alicia Ritzenhaler, Eva Kramer, Lauren Fry, Eric Anderson, Drew Gronewold and in collaboration within GLERL and University of Michigan's Cooperative Institute for Limnology and Ecosystems Research.

Our team uses a process based pollutant fate and transport model in order to simulate the process of bacteria accumulating on the ground and being washed into the river/steam/etc. when it rains. The amount of fecal indicator bacteria (FIB) in the river then becomes the input value for the hydrodynamic model; which simulates where this bacteria goes in the lake. Linking the two models together this way for use as a forecasting tool assumes that the watershed makes a significant contribution to the nearshore water quality. Specifically, it assumes that pollution introduced to the nearshore environment directly from the landscape (i.e. waterfowl dropping on the beach water directly into the lake) is negligible relative to the contribution introduced via river(s).

In order to make sure that our forecasting system is working well, we need to be able to confirm its results. Since June 2012 our team has been collecting weekly samples from nearshore locations in Macomb County, MI to analyze for FIB. Our results give us real data we can compare to the model to. The overall goal is to develop a model and decision support system for many watersheds within the Great Lakes. To learn more, please check out the project's website (best viewed in Mozilla Firefox or Google Chrome/Chromium).


60 hour Beach Forecasting Model

University of Michigan's Cooperative Institute for Limnology and Ecosystems Research received a grant to develop a process to forecast beach water quality in the Great Lakes. David Rockwell and Kent Campbell used weather data from the National Weather Service (NWS) and NOAA's Great Lakes Environmental Research Laboratory`s Coastal Forecasting System capable of generating 60-hour forecasts of fecal bacteria at 24 beaches in Indiana, Wisconsin, Ohio, Michigan, New York, and Pennsylvania.

The project compared the accuracy of its bacteria forecasts with predictions based on the previous day's bacteria concentration. Decision support systems (DSS) developed with the Virtual Beach 2.3 software (regression based model), resulted in fewer errors at 70% of the sites. Principal conclusions and implications for future work: 1) At the sites studied, E.coli variation was influenced by weather patterns. 2) Forecast independent variables explain up to almost 40% of the variation in beach E.coli concentrations. 3) This study reinforced the concept that a beach with 5% or fewer samples exceeding the State Regulatory E. coli standard may not be suitable for predictive modeling. This allows a beach manager to quickly determine if a forecast DSS should be attempted if the samples exceeding the standard is above 5%.

If forecast DSS are used by County Health Departments where sufficient bacterial data is available, timely and more accurate advisories could be issued. This could result in recreational water users avoiding unnecessary health risks. At Great Lake beaches potential substantial economic loss from banning swimming unnecessarily could be avoided and beach microbial sources could be targeted for remedial action.

As a result of this project, NOAA released Technical Memorandum GLERL-156 Beach Water Quality Decision Support System

NOAA beach water quality experimental forescasts: Poster from the Great Lakes Beach Association Conference October 16-17 2012


NOAA Beach Water Quality Experimental Forecasts

Timely accurate forecasts of beach water quality are critical to protect human health against adverse exposure situations. In collaboration with the National Weather Service, Detroit Pontiac Office, we have developed and tested beach management forecast decision support systems at five beaches in Michigan. The NOAA Beach Water Quality Experimental Forecasts are possible because Bay, Macomb, and Ottawa County Health Departments have provided their E. coli monitoring data. The beaches involved are:

  • Bay City State Rec. Area, Bay County, MI
  • Metro and Memorial Beaches, Macomb County,MI
  • North Beach Park and Grand Haven State Park, Ottawa County, MI

During 2012 swimming season between Memorial Day and Labor Day, the first three beaches were monitored approximately four times per week by Bay County and Macomb County Health Departments and the last two beaches were monitored approximately one time per week by the Ottawa County Health Department.

The National Weather Service Forecast Office in White Lake, Michigan (WFO DTX), will provide four forecasts each day for these five Michigan Beaches through the 2013 swimming season (Memorial Day to Labor Day). The four forecasts are generated at midnight, 6 am, Noon and 6pm EDTon a given day. These forecasts are aimed at predicting water quality bacterial concentrations for the 8 am expected morning sampling time or the 8 am sampling time the next day. Forecast output will include a minimum value, a most likely value, and maximum expected values of E. coliconcentrations.

Just like a weather forecast, the NWS provides an estimate of the chance that E. coli counts will exceed the Michigan's State standard of 300 E. coli counts per ml. These forecasts are made available to beach managers by the National Weather Service as one tool to help the beach manager determine water quality bacterial concentrations.

Links to decision support systems:


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Frequently Asked Questions

Harmful Algal Blooms

General

What is an algal bloom?

An algal bloom occurs when the numbers of algal cells increase rapidly to reach concentrations usually high enough to be visible to the naked eye. Many types of algae form blooms. Not all algal blooms are toxic. Some, such as the blooms of diatoms in the early spring, are very important to the health of the ecosystem.

What is a HAB?

HAB stands for Harmful Algal Bloom. There are many species of single-celled organisms living in the oceans, including algae and dinoflagellates. When certain conditions are present, such as high nutrient or light levels, these organisms can reproduce rapidly. This dense population of algae is called a bloom. Some of these blooms are harmless, but when the blooming organisms contain toxins, other noxious chemicals, or pathogens it is known as a harmful algal bloom, or HAB. HABs can cause the death of nearby fish and foul up nearby coastlines, and produce harmful conditions to marine life as well as humans.

What are Cyanobacteria (blue-green algae)?

Blue-green algae is the common name for several different types of algae. They are actually bacteria (Cyanobacteria) which are able to photosynthesize, hence the green color. Cyanobacteria are bacteria that grow in water and are photosynthetic (use sunlight to create food and support life). Cyanobacteria live in terrestrial, fresh, brackish, or marine water. They usually are too small to be seen, but sometimes can form visible colonies. Cyanobacteria have been found among the oldest fossils on earth and are one of the largest groups of bacteria. Cyanobacteria have been linked to human and animal illnesses around the world, including North and South America, Africa, Australia, Europe, Scandinavia, and China. Cyanobacteria are the most common, but not the only, group of algae to from HABs.

What does a cyanobacterial bloom look like?

Some cyanobacterial blooms can look like foam, scum, or mats on the surface of fresh water lakes and ponds. The blooms can be blue, bright green, brown, or red and may look like paint floating on the water. Some blooms may not affect the appearance of the water. As algae in a cyanobacterial bloom die, the water may smell bad.

How do I know if water contains blue-green algae?

If you detect an earthy or musty smell, taste or see surface scums of green, yellow or blue-green the water may contain blue-green algae. Only examination of a water sample under the microscope will confirm the presence of blue-green algae.

How can I test for cyanobacterial toxins?

Most of the toxins require specialized testing that can weeks to perform. Some kits are available to test for microcystins on site.

Causes

What causes an algal bloom?

There is no single factor which cause an algal bloom. A combination of optimum factors such as the presence of good nutrients, warm temperatures and lots of light all encourage the natural increase in numbers of blue-green algae in our waterways. Nature mostly takes care of the temperature and light, but the increased presence of nutrients such as phosphorous is largely due to poor farming practices such as high use of fertilizers and presence of livestock near water supplies, as well as effluent and run-off from towns and cities near waterways. The ponding of water and reducing river flow rates tends to improve the light and sometimes the nutrient environment for algal growth making water turbulence a major factor in bloom development. Pesticides and other chemicals may affect the natural grazers which would otherwise control algal growth and their presence increases the risk of blooms.

How do cyanobacterial blooms form?

Cyanobacterial blooms occur when algae that are normally present grow exuberantly. Within a few days, a bloom can cause clear water to become cloudy. The blooms usually float to the surface and can be many inches thick, especially near the shoreline. Cyanobacterial blooms can form in warm, slow-moving waters that are rich in nutrients such as fertilizer runoff or septic tank overflows. Blooms can occur at any time, but most often occur in late summer or early fall. They can occur in marine, estuarine, and fresh waters, but the blooms of greatest concern are the ones that occur in fresh water, such as drinking water reservoirs or recreational waters.

I've heard zebra mussels are causing the blooms. How does that work?

Zebra mussels have been implicates as a factor promoting the formation of harmful algal blooms in the Great Lakes region, particularly for low-phosphorus inland lakes. By removing natural competitors (green algae) and/or altering the chemical composition of the water, zebra mussels may promote HABs. Zebra mussels have been shown to be capable of selecting which algae they consume -- spitting out presumably toxic forms such as Microcystis. By filtering the water, zebra mussels also increase the amount of light reaching the bottom of the lake, which promotes the growth of large benthic forms of algae such as Ciadophora which may break free during storms or due to wave action to form floating mats or wash up on the beaches.

Can you get a blue-green algal bloom in winter?

Yes, however, this is less likely than in summer. Algal blooms can occur at any time of year as long as conditions such as temperature and nutrients are right for growing.

Dangers

What are the dangers of Harmful Algal Blooms?

  • They spoil water quality when present in large numbers by producing odors or thick scums.
  • They can make drinking water smell and taste bad.
  • They can make recreational areas unpleasant.
  • Dense blooms can block sunlight killing other plants and animals.
  • When algae decompose they may use up oxygen in the water and cause fish kills.
  • Some cyanobacteria can produce toxins that are among the most powerful natural poisons know. These toxins have no know antidotes. The toxins are poisonous to humans and may be deadly to livestock and pets.
  • CyanoHABs can make people, their pets, and other animals sick. Often, the first sign that a HAB exists is a sick dog that has been swimming in a algae-filled pond. Children are at higher risk than adults for illness from CyanoHABs because they weigh less and can get a relatively larger dose of toxins.

Are all blue-green algae poisonous?

No. There are many species of blue-green algae. Some are not known to have any toxins, others have one or more different types of toxin. Species known to be toxic may only be toxic at certain times and places within the bloom. Blue-green algae are a natural part of all waterways. Under certain conditions some blue-green algae multiply to bloom levels and may produce toxins which are dangerous to livestock and humans.

What species of cyanobacteria form harmful algal blooms in fresh water?

The most common HABs in the Great Lakes region are:
  • Microcystis aeruginosa
  • Anabaena circinalis
  • Anabaena flos-aquae
  • Aphanizomenon flos-aquae
  • Cylindrospermopsis raciborskii

What types of illnesses can people and animals get from exposure to HABS?

  • Getting it on the skin may give people a rash, hives, or skin blisters (especially on the lips and under swimsuits).
  • Inhaling water droplets from irrigation or water-related recreational activities can cause runny eyes and nose, a sore throat, asthma-like symptoms, or allergic reactions.
  • Swallowing water that has toxins in it can cause:
    • Acute, severe gastroenteritis (including diarrhea and vomiting).
    • Liver toxicity (i.e., increased serum levels of liver enzymes). Symptoms of liver poisoning may take hours or days to show up in people or animals. Symptoms include abdominal pain, diarrhea and vomiting.
    • Neurotoxicity. These symptoms can appear within minutes after exposure. In dogs, the neurotoxins can cause salivation and other neurological symptoms, including weakness, staggering, difficulty breathing, convulsions, and death. People may have numb lips, tingling fingers and toes, or they may feel dizzy.
    • Paralytic shellfish poisoning (PSP). PSP is caused by consumption of shellfish (e.g., mussels and clams) which bioaccumulate a toxin produced by dinoflagellates (red tide). Dinoflagellates similar to those responsible for PSP are occasionally found in the Great Lakes, but dangerous levels of PSP toxin have not been observed there.

How could you be exposed to HABs and toxins?

  • Drinking water that comes from a lake or reservoir with a HAB.
  • Drinking untreated water.
  • Engaging in recreational activities in waters with HABs.
  • Inhaling aerosols from water-related activities such as jet skiing or boating.
  • Inhaling aerosols when watering lawns, irrigating golf courses, etc., with pond water.
  • Using cyanobacteria-based dietary supplements that are contaminated with microcystins.
  • Consuming contaminated fish or shellfish (see safety precautions below).

Health and Safety

How can you protect yourself, your family, and your pets from exposure to HABs?

  • Don't swim, water ski, or boat in areas where the water is discolored or where you see foam, scum, or mats of algae on the water.
  • If you do swim in water that might have a HAB, rinse off with fresh water as soon as possible.
  • Don't let pets or livestock swim in or drink from areas where the water is discolored or where you can see foam, scum, or mats of algae in the water.
  • If pets (especially dogs) swim in scummy water, rinse them off immediately - do not let them lick the algae (and toxins) off their fur.
  • Don't irrigate lawns or golf courses with pond water that looks scummy or smells bad.
  • Report any musty smell or taste in your drinking water to your local water utility.
  • Respect any water body closures announced by local public health authorities.

Is it safe for livestock to drink water with blue-green algae in it?

No. An alternative safe drinking supply must be found until the water supply is declared safe. Most livestock will prefer not to drink the water if an alternative supply is available.

Are all animals affected the same?

Most important is the amount of exposure to the toxins. Some animals are particularly sensitive. Dogs have sensitive noses and lick their fur to clean themselves, possibly taking in concentrated algae. Fish and water birds appear to be little affected. Most livestock will avoid contaminated water, if possible, but where they are forced to drink through scum (for example where a fence forces them to the leeward side of a dam) they may die.

Can livestock pick up toxins from irrigated pasture?

Yes. Some of the blue-green algal toxins will remain toxic in dry form. Continued application of heavily affected waters (say from dairy waste recycling dams) can lead to significant toxin build up on foliage. Although this is a rare occurrence requiring special circumstances, this residue can affect livestock.

Is blue-green algae affected water safe to drink after it has been boiled or filtered?

NO. The water needs to be filtered through activated carbon to remove any toxins. Toxins will not be removed by boiling, normal water filter systems or adding household disinfectant.

Can I cook with water with blue-green algae in it?

NO. Remember boiling does not remove toxins from the water.

Can I wash clothes and dishes in water with blue-green algae in it?

Where possible use alternative water supplies. If you are unable to find another water source, take the following precautions:
  • Use rubber gloves when handling wet washing or dishes.
  • Rinse dishes with uncontaminated water.
  • Remove surplus water with a dish towel.
  • If possible, give the laundry a final rinse with uncontaminated water. Sun dry the clothes and air them for a few days.

Can I water fruit and vegetables with contaminated water?

Yes. These do not appear to take up the toxins. However, avoid fruit and vegetables coming in contact with the contaminated water. Make sure you wash the fruit and vegetables in clean water before eating.

Can I eat fish or shellfish caught in water with blue-green algae in it?

You should not eat shellfish as they can concentrate toxins. The liver and gut of fish are also likely to be toxic. Other parts of the fish may be eaten but they must be well cleaned. Further studies need to be done on the build-up of toxins in fish.

Is it safe to swim in water with blue-green algae in it?

Generally no. This will depend on the numbers and type(s) of algae present. At even low levels of some blue-green algae people and animals with sensitive skin may show some allergic reactions to the toxins present in the water. Not all people are sensitive to blue-green algae allergens and for those who are the effect increases with increased exposure. The more concentrated the algae and the longer people remain in the water the more severe the symptoms.

Is it safe to boat or canoe in water where there is an algal bloom?

Safety will depend on the level of the blue-green algae. Always avoid skin contact with the water. Not all people are sensitive to blue-green allergens and for those who are, the effect increases with increased exposure. The more concentrated the algae and the longer people remain in the water the more severe the symptoms.

Will wearing a wetsuit protect me from algal toxins?

No. In fact wetsuits may concentrate algae at the collar and cuff areas and rub cells against the skin. This may cause a particularly strong skin reaction at the points where water enters the suit. Be careful to rinse algae off the suit with fresh water if you have used it where algae concentrations are high.

Will blue-green algae affect my irrigated crops?

Not directly in relation to toxins. The crops are not known to take up the toxins. However, blue-green algae are fast growing and can shade and foul rice crops if they occur in bays before the crop established a cover above water level. This can cause significant yield loss

When blue-green algae is present should I pump water from a greater depth?

Water in deep dams may form layers of different temperature. If there is no alternative water supply using water form areas not covered by scums or from deeper (notably cooler) layers in dams MAY reduce algal exposure and risks.

Is the water safe once it appears to no longer have a bloom on it?

No. Blue-green algal cells lave gas bubbles in them which affect how they float. It is common for blooms to rise to the surface in calm light conditions and sink down at other times becoming much less evident from the bank. When cells die and break up it can take days for nerve toxins to disintegrate and weeks for liver toxins to disappear. It is best to wait a couple of weeks after a scum forming bloom has gone before using the water

How to treat people or animals that have been exposed to cyanobacterial toxins?

Get medical treatment right away if you think you, your pet, or your livestock might have been poisoned by cyanobacterial toxins. Remove people from exposure and give them supportive treatment.

Prevention

How can I prevent an algal bloom?

Algae need three things for optimal growth: light, nutrients and high temperatures. Lowering the nutrients, light and temperature available to the blue-green algae in the water supply will help reduce algal growth. The speed at which water is flowing and mixing is important in controlling light and nutrient availability to algal cells. Keeping livestock away from the farm dam or water supply; avoiding run-off into water supply from fertilizers and pesticides; taking some water treatment measures BEFORE bloom starts; and if practical - changing mixing patterns or covering the dam or water supply to screen out light may help.

How can I reduce the occurrence of HABs?

Reduce nutrient loading of local ponds and lakes by using only the recommended amounts of fertilizers and pesticides on your yard. Properly maintain your household septic system. Maintain a buffer of natural vegetation around ponds and lakes to filter incoming water.

Can I use chemicals to treat water with blue-green algae in it?

Most chemicals work to PREVENT an algal bloom. Water in small dams can be protected from blue-green algae by dosing with gypsum and alum. These chemicals work by removing phosphorus from the water. Algaecides can be used to safeguard water for agricultural use in farm dams BEFORE algal blooms occur. However, if used to treat a bloom, the algaecide may cause a release of toxins into the water when it destroys the algae. Algaecides may be toxic to organisms that naturally control algal blooms or, if not correctly applied, to livestock and humans. Before using algaecides seek advice from the relevant authority.

Great Lakes Beach, Tributary, and Nearshore Water Quality

See the project page for more details.

What is nearshore water?

Nearshore water is typically defined to extend from the shoreline offshore to the depth at which the thermocline rests on the bottom of the lake in late summer/early fall (i.e. the depth at which the water warms clear through to the lake bottom; approx 20-30meters depth). It is the place which the terrestrial watershed directly interacts with the lake (or ocean).

What are fecal indicator bacteria (FIB)?

Fecal indicator bacteria (FIB) are bacteria such as E. coli and Entercoccus, which live in the gut of warm blooded animals and are introduced into the environment through fecal matter. Most FIB are harmless to humans. The presence of FIB indicates that pathogens also found in fecal matter, which are harmful to humans, may also be present.

Where do FIB come from?

Fecal indicator bacteria (FIB) could be coming from a number of different sources. FIB is found in the fecal matter of warm blooded animals. It can be introduced to the environment in a number of ways including, but not limited to, wildlife, livestock, leaking septic systems, and combined sewer overflows (CSOs). There are molecular methods, collectively referred to as bacterial source tracking, which allow scientists to determine if the bacteria are from human or non-human sources. Depending on the specificity of the method it is possible to determine the specific animal (cow, pig, geese, etc.). Our team does not conduct any source tracking.

How do you analyze water samples for E. Coli?

We quantify the concentration of E. Coli for this project using both membrane filtration and IDEXX Colilert methods. Membrane filtration allows for the quantification of E. Coli in a water sample by growing the organism on selective media which encourages E. Coli growth yet prevents the growth of other organisms. Each E. Coli organism in the water sample grows into a colony which is then counted.

The IDEXX Colilert method detects E. Coli when the organism metabolizes a nutrient indicator (MUG) using a unique enzyme (β-galactosidase) causing it to fluoresce. Results are reported by indicating the most probable number (MPN) of organisms present in every 100mL of water. After dissolving the nutrient indicator in the sample, it is poured into a special tray with a number of depressions, or 'wells'. The MPN is based on the number of E. Coli positive wells viewed under long-wave UV light (365nm).

What is the difference between routine sampling and rainfall event sampling?

Routine samples are samples collected on 'regular' days. These samples are collected, typically weekly, as part of a regular schedule. Rainfall event sampling is sampling which occurs very shortly after it rains (typically within 24 hours). We collect rainfall event samples because we anticipate more bacteria to wash off the landscape into the river immediately following a rain than it would on routine day.

What is a pollutant fate and transport model?

A pollutant fate and transport model allows us to simulate and predict the process by which bacteria accumulates on the landscape and washes off into nearby rivers or lakes. By doing so, it tells us how much bacteria is entering the river or late on any given day. We do this using rainfall, estimating the number of wildlife and leaking septic systems in the watershed, and accounting for the lifespan of the bacteria in different conditions.

What is a hydrodynamic model?

A hydrodynamic computer model is a tool that simulates the physical environment of the water body, describing the motion and the energy of the water to predict aspects such as currents, temperatures, and water level fluctuations. The hydrodynamic model uses information from meteorologic information (wind speed/direction, air temperature, cloud cover, dewpoint temperature, solar radiation) and connected tributaries (inflows/outflows) to make these predictions.

Why do you need to collect and analyze water samples if you can predict water quality?

We need to collect and analyze water samples in order to confirm that our models are working well. The closer the model can predict to what we observed the better. We can't be sure the modeling is working unless we have 'observed' results to compare it too.

Are you working with the health department?

We work with the health department to the extent that we communicate regularly to share data and project updates as well as to discuss overlapping/related nearshore water quality topics. We do not actively work on the same projects. Although we share the same overarching goal to protect public health, we play two distinct, yet equally important, roles.

How is your project different from what the health department is doing?

Our project is related to the work of the health department however it is distinctly different as well. The role of local health departments (among its many responsibilities) is to monitor the swimming areas and determine if advisories or closures should be posted. Rather than to determine if water is safe for public recreations (such as swimming), the goal of our project is to develop decision support tools for use by beach managers and public health officials who are responsible for posting beach advisories and closures.

Contacts

At GLERL