Black Lake2009 Report

What attracts people to Northern Michigan? In general,people come north to enjoy the natural beauty of the area'spristine ecosystems, but if asked for one specific landscapefeature, most would undoubtedly say our "lakes". Lakesdefine the landscape of Northern Michigan and sustainlocal economies, providing stunning views, abundantfisheries, and tremendous recreational opportunities.

In the Tip of the Mitt Watershed Council service area thereare nearly 60 lakes greater than 100 acres in size,and 14 of these are among the State’s largest withover 1,000 acres of lake-surface area. Theregion also boasts some of the State’s deepestlakes with five lakes having maximum depths of100 feet or more. Black Lake, in eastern CheboyganCounty, stands among these lake “giants” withover 10,000 acres of surface area and 50 feetof depth.

True to its name, the waters of Black Lake aredark, obscured by tannins, yet exceptionally cleanand pure. Within its mysterious waters you will findan enchanting and vibrant ecosystem; from thelarge prehistoric sturgeon inhabiting its depths tothe resplendent purple pickerel weeds emergingfrom its surface. Over the last few decades, theWatershed Council has put forth great effortto preserve Black Lake and ensure it remains ahigh quality resource for the enjoyment of futuregenerations. Water quality of the region’s lakes,both large and small, has been monitored by staffand volunteers alike, providing valuable data onthe overall health of our waters. Our cornerstonewater quali ty monitoring programs includeComprehensive Water Quality Monitoring andVolunteer Lake Monitoring.

The Comprehensive Water Quality Monitoringprogram is run byWatershed Council staff who havemonitored water quality of Northern Michigan’slakes and streams for over 20 years. The VolunteerLake Monitoring program was started in 1984 andhas relied on hundreds of dedicated volunteers whomonitor water clarity, algae abundance, phosphoruslevels and more.

In addition to monitoring, the Watershed Councilhas worked with lake shoreline owners and lakeorganizations on a variety of projects to protect thelakes scattered throughout Northern Michigan.

Projects carried out on these lakes have ranged from com-prehensive aquatic plant surveys to shoreline restorationprojects. Details about recent monitoring activities and lakeprojects on Black Lake are included in this report.

We hope you find this report both informative and helpful.If you have any questions, comments, or concerns, pleasecontact Tip of the Mitt Watershed Council at (231) 347-1181or visit our website at www.watershedcouncil.org.

Over the last few decades, Tip of the Mitt Watershed Council has putforth great effort to preserve Black Lake and ensure it remains a highquality resource for the enjoyment of future generations.

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Comprehensive Water Quality Monitoring

Water Quality Trends: 20 years of data

In 2007, Tip of the Mitt Watershed Council completed its In2007, Tip of the Mitt Watershed Council completed its 20thyear of comprehensive monitoring. Starting on just 10 lakesin 1987, the Watershed Council’s Comprehensive WaterQuality Monitoring Program has expanded to include over50 lakes and rivers throughout Northern Michigan. Anincredible amount of data has been generated from thisprogram and is utilized by the Watershed Council, lake andstream associations, local governments and regulatoryagencies in an effort to protect and improve the waterresources that are so important to the region.

Every three years, Watershed Council staff head into thefield as soon as ice is out to monitor lakes and rivers spreadacross the tip of the mitt. Over 60% of the region’s lakesgreater than 100 acres in size, and all major rivers areincluded in the program. In each of these water bodies, theWatershed Council collects a variety of data, includingparameters such as dissolved oxygen, pH, chloride,phosphorus and nitrogen.

Information gathered in the Comprehensive Water QualityMonitoring Programhas proven to be very useful. The data areused by the Watershed Council and others to characterizewater bodies, identify specific problems and examine trendsover time. One obvious trend found by analyzing data fromthis program is that chloride (a component of salt) levelshave increased significantly in many water bodies during thelast 22 years. Why? We need not look any farther than our-selves to find the answer as we use salt in everything fromde-icing to cooking.

The following pages contain descriptions of the types of datacollected in the program as well as select data from BlackLake. We have also included charts to provide a graphicdisplay of trends occurring in the lake. For additionalinformation about the Comprehensive Water QualityMonitoring Program please visit our web site at www.watershedcouncil.org/protect

Parameters and Results

pHpH values provide a measurement of the acidity or alkalinityof water. Measurements above 7 are alkaline, 7 is consideredneutral, and levels below 7 are acidic. When pH is outsidethe range of 5.5 to 8.5, most aquatic organisms becomestressed and populations of some species can becomedepressed or disappear entirely. State law requires that pH

be maintained within a range of 6.5 to 9.0 in all waters of thestate. Data collected from Black Lake show that pH levelsconsistently fall within this range, with a minimum of 7.35(1992) and maximum of 8.39 (2001).

Dissolved OxygenOxygen is required by almost all organisms, including thosethat live in the water. Oxygen dissolves into the water fromthe atmosphere (especially when there is turbulence) andthrough photosynthesis of aquatic plants and algae. Statelaw requires that a minimum of 5 to 7 parts per million (PPM)be maintained depending on the lake type. Dissolvedoxygen levels recorded in Black Lake have consistentlyexceeded State minimums, ranging from 8.8 PPM (1998) to13.6 PPM (1995).

ConductivityConductivity is a measure of the ability of water to conduct anelectric current, which is dependent upon the concentrationof charged particles (ions) dissolved in the water. Readingson lakes monitored by the Watershed Council have rangedfrom 175 to 656 microSiemens (µS), and in Black Lake,ranging from a low of 225 µS (1987) to a high of 294 µS(2004). There was a trend of increasing conductivity levelsfrom 1987 to 2004, followed by a decrease in 2007.A steadyincrease in conductivity levels generally occurs due togreater human activity in the watershed and may indicatethat water pollution is occurring.

Kevin Cronk, our Monitoring and Research Coordinator, measures thewater clarity on Black Lake with a secchi disc. This is just one of the

many tests done to thoroughly check the health of the lake.

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Chloride

Chloride, a component of salt, is present naturally at lowlevels in Northern Michigan surface waters due to the marineorigin of bedrock (typically < 5 PPM). Chloride is a “mobileion,” meaning it is not removed by chemical or biologicalprocesses in soil or water. Many products associated withhuman activities contain chloride (e.g., de-icing salts, watersoftener salts, and bleach).Althoughmost aquatic organismsare not affected until chloride concentrations exceed 1,000PPM, increasing chloride concentrations are indicative ofother pollutants associated with human activity (such asautomotive fluids from roads or nutrients/bacteria from septicsystems) reaching our waterways. Chloride concentrationshave tripled in Black Lake, from a low of 2.0 PPM in 1987to a high of 6.8 PPM in 2007.

Total Phosphorus

Phosphorus is themost important nutrient for plant productivityin surface waters because it is usually in shortest supplyrelative to nitrogen and carbon. Awater body is consideredphosphorus limited if the ratio of nitrogen to phosphorus is

greater than 15:1. In fact, most lakes monitored by theWatershed Council are found to be phosphorus limited.Although water quality standards have not been set forlakes, the U.S. EPA recommends that total phosphorusconcentrations in streams discharging into lakes not exceed50 parts per billion (PPB). Phosphorus is normally found atconcentrations of less than 10 PPB in high quality surfacewaters. In Black Lake, total phosphorus concentrationshave decreased during the last two decades, falling from10PPB in 1987 to approximately 4 PPB in 2007.

Total Nitrogen

Nitrogen is another essential nutrient for plant growth. It isa very abundant element throughout the earth’s surfaceand is a major component of all plant and animal matter.Although nutrients occur naturally, nutrient pollution is usuallythe result of human activities (e.g. fertilizers, faulty septicsystems, and storm water runoff). In general, the lowestnutrient levels were found in Lake Michigan and large deepinland lakes, while the highest nutrient levels were found insmall shallow lakes. Total nitrogen levels in Black Lakehave ranged from 223 PPB in 1998 to 1010 PPB in 1987.Nitrogen concentrations have gone up and down with ageneral trend of decreasing levels over time.

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Comprehensive Water Quality Monitoring Program2007 Data

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Phragmites and Quagga MusselSurveys on Black Lake

With two new invasive species on the horizon the Tip of theMitt Watershed Council, with support from the Black LakeAssociation, was awarded a grant to survey the region’slakes for these emerging threats. Grant funding from theNational Fish and Wildlife Foundation is being used tointensively survey lakes and rivers throughout the CheboyganRiver watershed for the presence of an invasive tall grasscalled Phragmites and an invasive mollusk called quaggamussels. Black Lake was surveyed for Phragmites in thesummer of 2008 and surveyed for quagga mussels duringthe 2009 field season.

There are now two types of Phragmites found in NorthernMichigan: native Phragmites and invasive Phragmites.Both varieties inhabit wet areas, whether shorelines, openwater, or wetlands, and are distinct in that they are tallgrasses that can reach over 15 feet in height (12’ highestyet recorded for the native). The native type is part of NorthernMichigan’s natural ecosystem, intermingled and co-existingwith other native wetland plant species. The invasive typehowever, grows in dense stands, crowding out native speciesand dominating wetland areas. In Southern Michigan andmany other areas throughout the United States, the invasivePhragmites has proliferated to cover extensive coastalareas, such as in SaginawBay where it completely dominatesthousands of acres.

Quagga mussels are relatives of the invasive zebra musselsthat have become so prolific and problematic in our lakesand streams. Like zebra mussels, quaggas filter feed onfree-floating algae in the water (up to 1 liter/day/mussel).Quagga mussels however, have far greater impacts on ouraquatic ecosystems for a variety of reasons. Quaggas arefound at greater depths and do not hibernate in the winterlike zebra mussels. Lake Michigan and the other GreatLakes are now dominated by quagga mussels,which arecausing major changes in the lake ecosystem by filtering outthe algae that are the base of the food chain. Surprisinglyand fortunately, quagga mussels have not yet been foundin any inland lakes in Michigan.

Survey results thus far are VERY encouraging. Phragmiteswas found at 34 locations along the Black Lake shorelineand even out in open water in the northwest corner of thelake. Fortunately, every stand found was of the native variety.Results from the quagga mussel survey give us anotherreason to celebrate: 16 areas were surveyed in Black Lakeand not a single quagga mussel found! The WatershedCouncil will continue working with the Black LakeAssociationto track the spread of these invasive species and to keepthem out of Black Lake and adjoining waters.

Partnering to ProtectBLACK LAKE

Quagga mussels are relatives of the invasive zebra mussels that havebecome so prolific and problematic in our lakes and streams. Fortunately,quagga mussels have not yet been found in any inland lakes in Michigan.

Kevin Cronk, Monitoring and Research Coordinator for Tip of the MittWatershed Council, surveys a stand of Phragmites on Black Lake.

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Volunteer Lake Monitoring

Local VolunteersMonitor & Protect Our Lakes

Since 1984, Tip of theMittWatershedCouncil has coordinatedthe Volunteer Lake Monitoring program (VLM), relying uponhundreds of volunteers to monitor the water quality of dozensof lakes in the northern Lower Peninsula of Michigan. Duringthe summer of 2008, 40 volunteers monitored water quality at33 stations on 25 lakes.

A tremendous amount of data has been generated by the VLMprogram and is available to the public via our web site(www.watershedcouncil.org/protect). This data is essential fordiscerning short-term changes and long-term trends in thelakes of Northern Michigan. Ultimately, the dedicated effort ofvolunteers and staff will help improve lake management andprotect and enhance the quality of NorthernMichigan’s waters.

Volunteers measure water clarity on a weekly basis usinga Secchi disc. Every other week volunteers collect watersamples to be analyzed for chlorophyll-a. Staff at theWatershed Council process the data and determine TrophicStatus Index (TSI) scores to classify the lakes and makecomparisons. On Black Lake, volunteers have monitoredwater quality since 1987 near the deepest part of the lake.The following section summarizes the results.

Secchi Disc

The Secchi disc is a weighted disc (eight inches in diameter,painted black and white in alternating quarters) that is usedto measure water clarity. The disc is dropped down throughthe water column and the depth at which it disappears isnoted. Using Secchi disc measurements, we are able todetermine the relative clarity of water, which is principallydetermined by the concentration of algae and/or sediment in

the water. The clarity of water is a simple and valuable wayto assess water quality. Lakes and rivers that are very clearusually contain lower levels of nutrients and sediments and,in most cases, boast high quality waters. Throughout thesummer, different algae bloom at different times, causingclarity to vary greatly. Secchi disc depths have ranged fromjust a few feet in small inland lakes to 40-50+ feet in largeinland lakes and Great Lakes’ bays.

Chlorophyll-a

Chlorophyll-a is a pigment found in all green plants, includingalgae. Water samples collected by volunteers are analyzedfor chlorophyll-a to determine the amount of phytoplankton(minute free-floating algae) in the water column. There is astrong relationship between chlorophyll-a concentrations andSecchi disc depth. Greater amounts of chlorophyll-a indicategreater phytoplankton densities, which reduce water clarityand, thus, the Secchi disc depth as well. So why collectchlorophyll-a data? The chlorophyll-a data provides supportfor Secchi disc depth data used to determine the productivityof the lake, but it can also help differentiate between turbiditycaused by algal blooms versus turbidity caused by otherfactors such as sedimentation or calcite.

Trophic Status Index

Trophic Status Index (TSI) is a tool developed by BobCarlson,Ph.D. from Kent State University, to determine the biologicalproductivity of a lake. Formulas developed to calculate theTSI value utilize Secchi disc depth and chlorophyll-ameasurements collected by our volunteers. TSI values rangefrom 0 to 100. Lower values (0-38) indicate an oligotrophic orlow productive system, medium values (39-49) indicate a

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mesotrophic or moderately productive system, and highervalues (50+) indicate a eutrophic or highly productive system.Lakes with greater water clarity and smaller phytoplanktonpopulations would score on the low end of the scale, whilelakes with greater turbidity and more phytoplankton wouldbe on the high end.

TSI values do not measure water quality, but simply placethe lake on a scale of biological productivity. Oligotrophiclakes are characteristically deep, clear, nutrient poor, andwith abundant oxygen. On the other end of the spectrum,eutrophic lakes are shallow, nutrient rich and full ofproductivity, which when excessive can lead to oxygendepletion. Mesotropic lakes lie somewhere in between andare moderately productive.

Lakes may be placed in the eutrophic category as a resultof algal blooms, which are often a public concern and canbe indicative of water pollution problems. On the otherhand, low productivity of oligotrophic lakes may result ina lackluster fishery when compared to highly productiveeutrophic lakes.

(2008 TSI Values forall lakes on back page.)

Results from Black LakeVolunteer monitors have collected water quality on BlackLake for over 20 years! Since 1987, the lake has beenmonitored near its deepest point in the southern half of thelake. The long-term Secchi disc and chlorophyll-a data fromthis site allow Watershed Council staff to assess waterquality and examine changes over time.

During the last 20 years, average Secchi disc depths inBlack Lake have increased while average chlorophyll-aconcentrations have decreased. These changes occurredin a time period that coincides with the introduction of theinvasive zebra mussel. Zebra muscles are voracious filter-feeders that feed upon algae and essentially clear the watercolumn. Unfortunately, zebra mussels are not cleaning thewater, but rather removing the algae that are the base ofthe food chain and ultimately, causing ecosystem disruptions.Their feeding habits make them a very likely culprit for thechanges we are seeing in Black Lake.

Trophic status index numbers show that Black Lake waspreviously in the mesotrophic category (moderatelyproductive), but has dropped into the oligotrophic category(low productivity). Initial TSI scores of around 40 from theearly 1990s have dropped considerably and now fallconsistently in the 25 to 30 range. At one point borderingbetween mesothophy and oligotrophy, Black Lake appearsto have moved into the oligotrophic category for the long-term. Even with tannins its waters have become clearer,nutrient levels have dropped, but dissolved oxygen levelsremain high.

Overall, data show that Black Lake has exceptionally highquality waters. Without dedicated volunteers, we wouldhave less data, so we would like to send out a big “thank

you” to all those that have helped with theprogram. We would also like to encourageothers to become involved with ourvolunteer program to help us monitorand protect the aquatic treasures ofNorthern Michigan.

If you would like to get involved, pleasecontact the program coordinator, KevinCronk, at (231) 347-1181 ext. 109 or bye-mailing kevin@watershedcouncil.org.

Tools of the Trade...Volunteer Lake Monitors use aSecchi disc to measure water clarity.

426BayStreetPetoskey,MI49770

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Special Thanks to Our Black Lake VolunteersWe couldn’t do it without you.

Trophic Status Index (TSI) Values for Lakes Monitored in 2008

Bass Lake 44

Black Lake 28

Burt Lake, Central Basin 34

Burt Lake, North 34

Burt Lake, South 36

Crooked Lake 38

Douglas Lake - Cheboygan 39

Douglas Lake - Otsego 42

Elk Lake 38

Lake Charlevoix, Main 24

Lake Charlevoix, South Arm 32

Huffman Lake 31

Lake Marion 23

Lake Michigan, Bay Harbor 14

Lake Michigan, Little Traverse Bay 27

Long Lake, Cheboygan County 31

Mullett Lake, Center 25

Mullett Lake, Pigeon Bay 32

Munro Lake 39

Paradise Lake 45

Pickerel Lake 38

Six Mile Lake 44

Thayer Lake 43

Thumb Lake 32

Twin Lake 38

Walloon Lake, Foot Basin 34

Walloon Lake, North 37

Walloon Lake, West Arm 33

Walloon Lake, Wildwood 33

Lake TSI Lake TSI Lake TSI