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LAKE HIWASSEE. BLUE GREEN ALGAE Public Education Information Presented by : July 12, 2013 Marshall Environmental Management, Inc 1601 SW 89 th Street, Suite A-100 Oklahoma City, OK 73159. Dr. Charles L. Marshall, Ph.D., CIH Certified Industrial Hygienist. Senate Bill 259. SB 259
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LAKE HIWASSEE BLUE GREEN ALGAEPublic Education Information Presented by: • July 12, 2013 • Marshall Environmental Management, Inc • 1601 SW 89th Street, Suite A-100 • Oklahoma City, OK 73159 Dr. Charles L. Marshall, Ph.D., CIH Certified Industrial Hygienist
Senate Bill 259 SB 259 • This Bill created an Oklahoma Law that delegated specific requirements to: • Oklahoma Tourism and Recreation Department • State Department of Health • Both are directed to educate and provide information on BGA, its health effects, and issue • ADVISORIES– the advisories are to be posted by any state or municipal agency with Authority to manage a recreational lake or reservoir. • Private Lakes voluntarily cooperate on an individual basis.
Blue Green Algae - BGA Basic Biology • Blue Green Algae are now referred to as Cyanobacteria • They are microorganisms that flourish in water bodies where conditions become limiting for the growth of other forms of algae. Algae are part of the plankton, which are microscopic aquatic life forms that are suspended in the water column. • BGA grow best when the conditions for other more beneficial algae become limiting. Such as when the nutrients required to support growth of the more complex competing forms of algae are used up. • As a result, BGA can dominate or “Bloom” because they get all the food they need from just photosynthesis. Another attribute of BGA includes their ability to fix (obtain) nitrogen from the air. Nitrogen is an essential element in protein and DNA synthesis.
What Factors InfluenceBGA Blooms Eutrophication Eutrophication plus - • Pollution of the Lake by increased nutrient loading leading to detrimental changes in water quality that result in Algae Blooms. • Primarily influenced by human activities in land use and factors that allow the runoff of nutrients into the watershed from urbanization, agricultural use of fertilizers, poorly treated sewage effluent, concentrated leakage from residential septic systems and related factors. • Warm Temperatures • Season of Prolonged Sunlight • Combined with nutrients Consultant’s Anecdotal Observation: Seasonal changes, that include multiple warmer summers, may contribute to changes in the succession or the pattern of “normal” freshwater plankton growth, which leads to more frequent or denser BGA Blooms from one year to the next.
Other Contributing Factors Major Contributors Lesser Contributors • Sunlight – essential for photosynthesis • Phosphorus – major nutrient controlling algae blooms • Temperature– Surface water warms. That factor greatly enhances a zone in the water column suitable for bloom formation. • Turbulence– The action of wind, boat wakes and other recreation, disrupt the surface of the lake where environmental factors favor the growth of these specific phytoplankton. • Trophic Factors* – lesser seasonal variations in water temperature, along with eutrophorication, may prevent the replacement of BGA with a more diverse biota, resulting in a perpetual consequence, seen in the occurrence of annual blooms of BGA. * Note: This is referring to a very complex interaction of factors that influence the growth of competing forms of plankton and other organisms. • Nitrogen- Some BGA can obtain nitrogen from the Atmosphere (i.e. fix nitrogen). So they don’t depend on nitrogen from the nutrients that are entering the lake. • Nitrogen Compounds – However, the loading of different forms of nitrogen into the lake (ammonia and nitrate nitrogen) starts the process of accelerating algae growth, which often ends up allowing specific types of BGA to dominate when growth conditions limit the growth of other types of phytoplankton. • Lake Water Level – Fluctuation in water levels, the lack of a consistent outflow or discharge from a lake or reservoir, can influence the distribution and occurrence of phytoplankton, and in some cases restrict or enhance the growth of phytoplankton. These factors are temporary, and correlate with season rainfall or lake withdrawal patterns.
Type of Dominant BGA Found at Lake HiwasseeAphanizomenon sp. at approx. 78,400 cells/ml1 – typically Aphanizomenon flos-aqua Species like Aphanizomenon are filamentous, greatly increasing the cell count per milliliter of water the occupy. They also can produce gas vacuoles that enhance there ability to float at the surface creating obnoxious green blooms. 1DEQ Sampling Data from 6/4/13.
Toxins versus Cell Counts for BGA Not All Forms make Toxins Dense Growths or Blooms Aphanizomenon – looks like grass clippings Aphanizomenon Microcystisaeruginosa Microcystis aeruginosa – looks like a surface scum
Current Guidelines • WHO Guidelines: • World Health Organization guidelines for moderate probability of adverse health effects of one hundred thousand (100,000) cells per milliliter for cell count and twenty (20) micrograms per liter for microcystin toxin levels. • Cell Counts: • May vary based on type of BGA (filamentous vs. unicellular), sampling location (surface vs. subsurface), lab procedures and experience of analyst. • Toxin Levels: • Can vary widely based on type of BGA and factors that influence toxin formation (specific to life cycle of the organisms).
Advisory Criteria1 BGA Cell Count BGA Toxin • Titer – refers to density , concentration as “cell counts” of BGA in a water sample. Requires trained analyst with experience in taxonomy of freshwater phytoplankton. • Alert Level– 100,000 cells/milliliter (or 100 million cells per liter) • Visible Scum – Visible as a green mass or mate, typically on downwind side of water body or at surface. Should be avoided, may be >100 times the alert level. Counting is difficult due to clumping of cells into mats or dense colonies. • Chlorophyll–a: Measured as a chemical extracted from algae cells, which does not identify species, but can be more reliable indicator for comparison purposes. 1WHO Guidelines and as provided in SB 259 2Note: Not all BGA are easily counted as individual cells. Many are filamentous . Counting bias can occur. Measurement of the level of Chlorophyll-a can be used for comparison, thus eliminating counting bias. • Biota and Toxins– Toxin in this context is not the same as that which we commonly associate with toxic chemicals. The BGA toxins are metabolites made by the microorganism in response to growth at a given point in there life cycle and often when presented with specific environmental factors. • Types of Toxins*: • Endotoxins - are contained inside the cells of the BGA, but ca be released when cells are damaged or die. Most BGA toxins are formed inside the cells. • Exotoxins – are excreted from the cells and can accumulate in a micro-environment around a community of cells (e.g. colony) • Level of Toxin – Current guidelines 1 have established a specific level for alert using microcystin** as the indicator compound for the presence of BGA toxin in the water sample. *Not all BGA species and strains make toxins ** Some data exists that Aphanizomenon sp. may not produce microcystin toxin.
Microcystin General Information WHO Guideline 20-µ/ml • Most common form of BGA Toxin. • Primarily found in freshwater samples. • Primarily target organ in high dose is Liver. • Persons with Liver ailments, history of Hepatitis diseases may be at greater risk. • Named after the BGA Microcystisaeruginosa • WHO reported in 1999 that there are relatively few documented cases of human illness from cyanotoxins • Toxins may be present in association with high BGA cell counts which are often found in areas of the water body where surface “scum” or wind-blow accumulations of BGA have concentrated on the surface. UNITS OF MEASURE (amount of toxin) • µ = microgram • 1 millionth of a gram • a packet of sugar is a gram (1-µ = less than one speck of sugar) TOXICITY – General Requirements: • Dose (amount), Duration, Route DOSE = Swimming in dense algae growth with visible scum are examples of a high risk activity. DURATION: Repeated ingestion, eye and skin contact increase the potential for health effects. ROUTE: Swallowing or entry through openings in skin, eyes, etc. BGA toxins can also also be in water used for irrigation or products containing extracts of BGA Source: Toxic Cyanobacteria in Water, WHO:1999
Alert Levels for BGA WHO states that it is difficult to define "safe" concentrations of cyanobacteria in recreational water in relation to allergenic effects or skin reactions, because individual sensitivities vary greatly.
Available Public Information(click on these Hyperlinks) • Okla. Dept. Tourism & Recreation Links to Tips on Lake Safety • DEQ BGA Fact Sheet • Purdue Univ. BGA Fact Sheet • What are Harmful Algae Bloom - USGS.pdf • Guidelines for Safe Recreational Water Environments • Guidelines for Sampling Cyanobacterial Toxin Studies - USGS 2010 • WHO Toxic Cyanobacteria in Water • Harmful Algae Bloom Strategy
Managing Lake Water QualityBGA Awareness and Control • Stress Individual Efforts. • Good Environmental Stewardship. • Adhere to WHO Guidelines for now. • Conduct Water Quality Trend Monitoring. • Educate/Evaluate Watershed Management Practices. • Adopt Best Management Practices for Land & Wastewater. • Review historical and future property/land use and indentify practices that are impacting the Lake. • Decide on making changes in the HOA By-Laws.
Management Planning Recommendations for Lake Hiwassee • More Data is needed to implement a Management Plan. • Recommend selecting 3-4 sampling locations for trend monitoring. • Field Data should include Depth, Oxygen, Temperature, SecchiDisc readings. • Lab Analysis for Total Cell Counts & ID, Chlorophyll-a, and a Microcystin Assay. • Periodically (quarterly) measure nutrient and fecal coliform levels. • Recommend shoreline and watershed assessments for Water Quality Impact Evaluations. This indentifies potential sources of pollutants and related factors. • Sampling locations should be marked on maps and assigned GPS coordinates (i.e. waypoints) so you can reliably reproduce sampling at nearly the same locations. • Institute a Best Management Practices Education Program for the Lake Hiwassee Area residents. • Establish a budget to conduct trend monitoring. • Purchase sampling equipment (Kemmer, Secchi Disk, Dissolved Oxygen & Temperature Meter) and sampling containers or use consult to perform work. • Review Association By-Laws and make needed changes/restrictions (e.g. restrictions on fertilizer use, maintenance requirements for septic systems, etc.) • d
Consultant Contact Information Dr. Charles L. Marshall, President Business Experience since 1987 as a Environmental Consultant with Marshall Environmental Management, Inc. 1601 SW 89th Street, Suite A-100 Oklahoma City, OK 73159 405-616-0401 E-mail: marshenv@swbell.net • Environmental Scientist, Biologist, Industrial Hygienist and Consultant • Former Limnologist with Oklahoma City County Health Department • Experience in Water Quality Trend Monitoring and Blue Green Algae Blooms • MS Research on Interactions of Phytoplankton and BGA • Ph.D. Dissertation on Oklahoma Water Quality Management • Extensive field experience in pollution investigation and assessment • Background in Public Health and Industrial Hygiene • 40 years of applied experience in assessing environmental/pollution impacts