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1 Marcellus Lakes 2017 Aquatic Vegetation, Water Quality, and 2018 Management Recommendations November, 2017

2 Marcellus Lakes 2017 Aquatic Vegetation, Water Quality, & 2018 Management Recommendations Report Restorative Lake Sciences West Spring Lake Road Spring Lake, Michigan Website:

3 Table of Contents Section 1: The Marcellus Lakes Summary (2017)... 4 Section 2: The Marcellus Lakes Water Quality Data (2017)... 5 Section 3: The Marcellus Lakes Aquatic Plants (2017) Section 4: The Marcellus Lakes Recommendations (2018)... 18

4 Section 1 Marcellus Lakes 2017 Aquatic Vegetation, Water Quality, & 2018 Management Recommendations Report The following information is a summary of key lake findings collected in T he overall condition of the Marcellus Lakes is ranked in the top 50% of developed lakes of similar size in the state of Michigan. All of the lakes have enough nutrients (phosphorus and nitrogen) to support rigorous algae and submersed aquatic plant growth. Invasive species such as Eurasian Watermilfoil, Curly-leaf Pondweed, and Starry Stonewort are able to thrive in these waters and thus are a challenge to the Marcellus Lakes ecosystem. It has been particularly a challenge since the milfoil in the Marcellus Lakes have been genetically determined to be hybridized, which makes the milfoil much more resistant or tolerant to aquatic herbicides and thus much higher doses will be needed for effective control in the future. Further complicating the treatment is the need to apply only Triclopyr nearshore as the systemic herbicide due to shallow well restrictions. Nearshore treatment of nuisance native aquatic plants has been restricted by the MDEQ to occur prior to June 15 unless the invasives are also present in those areas later in the season. Protection of the 26 native aquatic plant species is paramount for the health of the lakes fishery and these plants should only be managed in areas where they are dense enough to cause recreational issues. 4

5 Section 2 The Marcellus Lakes Water Quality Data (2017) Water Quality Parameters Measured There are hundreds of water quality parameters one can measure on an inland lake but several are the most critical indicators of lake health. These parameters include water temperature (measured in F), dissolved oxygen (measured in mg/l), ph (measured in standard units-su), conductivity (measured in micro-siemens per centimeter-µs/cm), total alkalinity or hardness (measured in mg of calcium carbonate per liter-mg CaCO 3/L), total dissolved solids (mg/l), Secchi transparency (feet), total phosphorus and total nitrate nitrogen (both in µg/l), chlorophyll-a (in µg/l), and algal species composition. Water quality is measured in the deep basins of the Marcellus Lakes each year. Table 1 below demonstrates how lakes are classified based on key parameters. The Marcellus Lakes would be considered eutrophic (quite productive) since they contain ample phosphorus, nitrogen, and aquatic vegetation growth but have excellent water clarity and moderate algal growth water quality data for the Marcellus Lakes are shown below in Tables 2-4. Table 1. Lake trophic classification (MDNR). Lake Trophic Status Total Phosphorus (µg L -1 ) Chlorophyll-a (µg L -1 ) Secchi Transparency (feet) Oligotrophic < 10.0 < 2.2 > 15.0 Mesotrophic Eutrophic > 20.0 > 6.0 < 7.5 5

6 Table 2. Fish Lake water quality parameter data collected in the deep basin (May 25, 2017). Depth ft Water Temp ºF DO mg L -1 ph S.U. Cond. µs cm -1 Turb. NTU Total Kjeldahl Nitrogen mg L -1 Total Alk. mgl -1 CaCO 3 Total Phos. mg L Table 3. Finch Lake water quality parameter data collected in the deep basin (May 25, 2017). Depth ft. Water Temp ºF DO mg L -1 ph S.U. Cond. µs cm -1 Turb. NTU Total Kjeldahl Nitrogen mg L -1 Total Alk. mgl -1 CaCO 3 Total Phos. mg L Table 4. Saddlebag Lake water quality parameter data collected in the deep basin (May 25, 2017). Depth ft. Water Temp ºF DO mg L -1 ph S.U. Cond. µs cm -1 Turb. NTU Total Kjeldahl Nitrogen mg L -1 Total Alk. mgl -1 CaCO 3 Total Phos. mg L

7 Water Clarity (Transparency) Data Elevated Secchi transparency readings allow for more aquatic plant and algae growth. The transparency throughout the Marcellus Lakes in late May was adequate (12-18 feet) to allow abundant growth of algae and aquatic plants in the majority of the littoral zone of the lakes. Secchi transparency is variable and depends on the amount of suspended particles in the water (often due to windy conditions of lake water mixing) and the amount of sunlight present at the time of measurement. Total Phosphorus Total phosphorus (TP) is a measure of the amount of phosphorus (P) present in the water column. Phosphorus is the primary nutrient necessary for abundant algae and aquatic plant growth. TP concentrations are usually higher at increased depths due to higher release rates of P from lake sediments under low oxygen (anoxic) conditions. Phosphorus may also be released from sediments as ph increases. The dissolved oxygen levels are low enough at the bottom to cause release of phosphorus from the bottoms of all three lakes. TP concentrations in late May, 2017 ranged from mg L -1 for the lakes which was slightly lower than in These concentrations are high and indicative of nutrient-rich (eutrophic) waters. Total Alkalinity Lakes with high alkalinity (> 150 mg L -1 of CaCO 3) are able to tolerate larger acid inputs with less change in water column ph. Many Michigan lakes contain high concentrations of CaCO 3 and are categorized as having hard water. Total alkalinity may change on a daily basis due to the re-suspension of sedimentary deposits in the water and respond to seasonal changes due to the cyclic turnover of the lake water. The alkalinity of the Marcellus Lakes was moderate in late May of 2017 and ranged from mg L -1 of CaCO 3 and indicates a moderately hard water lake system that is well-buffered. ph Most Michigan lakes have ph values that range from 6.5 to 9.5. Acidic lakes (ph < 7) are rare in Michigan and are most sensitive to inputs of acidic substances due to a low acid neutralizing capacity (ANC). The Marcellus Lakes are considered slightly basic on the ph scale. The ph of the Marcellus Lakes in late May of 2017 ranged from years to S.U. which is ideal for inland lakes. Conductivity Conductivity is a measure of the amount of mineral ions present in the water, especially those of salts and other dissolved inorganic substances. Conductivity generally increases as the amount of dissolved minerals and salts in a lake increases, and also increases as water temperature increases. The conductivity values for the Marcellus 7

8 Lakes in late May of 2017 were moderate and ranged from µs/cm. Severe water quality impairments do not occur until values exceed 800 µs/cm and are toxic to aquatic life around 1,000 µs/cm. Chlorophyll-a and Algal Species Composition Chlorophyll-a is a measure of the amount of green plant pigment present in the water, often in the form of planktonic algae. High chlorophyll-a concentrations are indicative of nutrient-enriched lakes. Chlorophyll-a concentrations greater than 6 µg L -1 are found in eutrophic or nutrient-enriched aquatic systems, whereas chlorophyll-a concentrations less than 2.2 µg/l are found in nutrient-poor or oligotrophic lakes. The mean chlorophyll-a concentrations in the Marcellus Lakes did not exceed 4.0 µg/l which is moderate for inland Michigan lakes and lower than in The algal genera were determined from composite water samples collected over the deep basins of the Marcellus Lakes in 2017 were analyzed with a compound bright field microscope. The genera present included the Chlorophyta (green algae; Figure 1): Chlorella sp., Cladophora sp., Scenedesmus sp., Chloromonas sp., Mougeotia sp., and Pandorina sp.; The Cyanophyta (blue-green algae; Figure 2): Gleocapsa sp. and Oscillatoria sp, the Bascillariophyta (diatoms; Figure 3): Synedra sp., Navicula sp., Fragilaria sp., and Cymbella sp. The aforementioned species indicate a diverse algal flora and represent a good diversity of alga with an abundance of diatoms that are indicative of great water quality. 8

9 Figure 1. A Green Alga Figure 2. A Blue-Green Alga Figure 3. A Diatom 9

10 Section 3 Aquatic Vegetation Data (2017) Status of Native Aquatic Vegetation in the Marcellus Lakes The native aquatic vegetation present in the Marcellus Lakes is essential for the overall health of the lake and the support of the lake fishery. The most recent survey in September of 2017 determined that there were a total of 26 native aquatic plant species in the Marcellus Lakes. These include 15 submersed species, 3 floating-leaved species, and 8 emergent species. This indicates a very high biodiversity of aquatic vegetation in the Marcellus Lakes. The overall % cover of the lake by native aquatic plants is low relative to the lake size and thus these plants should be protected unless growing near swim areas at nuisance levels. The most dominant native aquatic plant species in the summer of 2017, included: 1) Chara (Figure 4), a macro-alga that has a skunky smell and lies close to the lake bottom, 2) Cattails (Figure 5), which are an emergent aquatic plant found along much of the shorelines of the lakes, and 3) Common Waterweed (Figure 6) and Thin-leaf (Figure 7) Pondweed, which are both excellent fish forage and habitat. Table 5 below shows the native aquatic plant species found in the lakes in

11 Figure 4. Chara Figure 5. Cattails Figure 6. Common Waterweed Figure 7. Thin-leaf Pondweed 11

12 Table 5. Native aquatic plants found in Big Fish, Saddlebag, and Finch Lakes (May 25, 2017). Aquatic Plant Species Common Name Growth Form Frequency (%) Chara vulgaris Muskgrass Submersed 3.4 Potamogeton pectinatus Thin-leaf Pondweed Submersed 0.9 Potamogeton zosteriformis Flat-stem Pondweed Submersed 1.1 Potamogeton robbinsii Fern-leaf Pondweed Submersed 0.1 Potamogeton richardsonii Whitestem Pondweed Submersed 0.1 Potamogeton illinoensis Illinois Pondweed Submersed 0.1 Potamogeton amplifolius Large-leaf Pondweed Submersed 0.1 Potamogeton zosteriformis Flatstem Pondweed Submersed 1.1 Potamogeton natans Floating-leaf Pondweed Submersed 0.1 Potamogeton gramineus Variable Pondweed Submersed 0.1 Vallisneria americana Wild Celery Submersed 0.1 Myriophyllum verticillatum Whorled Watermilfoil Submersed 0.1 Ceratophyllum demersum Coontail Submersed 0.1 Elodea canadensis Common Waterweed Submersed 2.8 Utricularia vulgaris Bladderwort Submersed 0.1 Nymphaea odorata White Water lily Floating-Leaved 0.1 Nuphar sp. Yellow Water lily Floating-Leaved 0.3 Lemna minor Duckweed Floating-Leaved 0.1 Sagittaria sp. Arrowhead Emergent 0.1 Pontedaria cordata Pickerelweed Emergent 0.1 Peltandra virginica Arrow Arum Emergent 0.2 Typha latifolia Cattails Emergent 3.6 Iris pseudacorus Yellow Flag Iris Emergent 0.1 Scirpus sp. Bulrushes Emergent 0.1 Rhynchospora sp. Beak Rush Emergent 0.1 Decodon verticillata Swamp Loosestrife Emergent

13 Status of Invasive (Exotic) Aquatic Plant Species in the Marcellus Lakes The amount of Eurasian Watermilfoil (EWM; Figure 8), Curly-leaf Pondweed (CLP; Figure 9), and Starry Stonewort (Figure 10) present in the Marcellus Lakes varies each year and is dependent upon climatic conditions, especially runoff-associated nutrients experienced above average summer temperatures and precipitation, and consequently many lakes experienced nuisance milfoil and algal outbreaks of significant scope. The spring 2017 conducted on May 25, 2017 revealed that approximately 3.45, 1.43, and 3.82 acres of milfoil was found throughout Fish, Finch, and Saddlebag Lakes, respectively. On June 8-9, 2017, the milfoil was treated in all lakes with high dose granular Triclopyr (Renovate OTF ). Additionally, approximately 29.11, 8.45, and 6.2 acres of Curly-Leaf Pondweed was found throughout Fish, Finch, and Saddlebag Lakes, respectively. The treatments were very successful overall, and removed the pondweeds along with other nuisance Wild Celery growth in nearshore areas. Distribution maps of these invasive species are shown in Figures below. Figure 8. Eurasian Watermilfoil 13

14 . Figure 9. Curly-leaf Pondweed Figure 10. Starry Stonewort 14

15 Figure 11. Eurasian Watermilfoil distribution in the Marcellus Lakes (May 25, 2017). 15

16 Figure 12. Curly Leaf Pondweed distribution in the Marcellus Lakes (May 25, 2017). 16

17 Figure 13. Starry Stonewort distribution in the Marcellus Lakes (May 25, 2017). 17

18 Section 4 Management Recommendations for 2018 Continuous aquatic vegetation surveys are needed to determine the precise locations of EWM, Curly-leaf Pondweed, Starry Stonewort, or other problematic invasives in the Marcellus Lakes. These surveys should occur in late-may to early-june and again post-treatment in Restorative Lake Sciences will again oversee all aquatic herbicide treatments in 2018 as in previous years. Due to high densities of native aquatic vegetation in the Marcellus Lakes, the continued management of these species is recommended with the use of mechanical harvesting as in previous years if desired. This method was well-received in previous years and reduced the overall aquatic plant biomass so that less falls to the bottom and decays, contributing to muck on the lake bottoms. The plan for 2018 includes the use of higher doses of systemic aquatic herbicides due to the genetically determined strains of hybrid milfoil that require such doses for effective treatment. Higher doses such as Sculpin G at a dose of 250 lbs. per acre would be recommended offshore and a dose of 250 lbs. per acre for Renovate OTF nearshore for effective control of the hybrid milfoil. Curly-leaf Pondweed will respond well to Aquathol-K at 1-2 gallons per acre. Starry Stonewort will respond well to a mixture of Clipper at 200 ppb and chelated copper. In conclusion, the Marcellus Lakes are a healthy lake ecosystem with good aquatic plant biodiversity, excellent water clarity, moderately high nutrients, and a healthy lake fishery. Management of all invasives and nuisance native weeds and protection of the water quality are paramount for the long-term health of the lake. 18

19 Glossary of Scientific Terms used in this Report 1) Biodiversity- The relative abundance or amount of unique and different biological life forms found in a given aquatic ecosystem. A more diverse ecosystem will have many different life forms such as species. 2) CaCO3- The molecular acronym for calcium carbonate; also referred to as marl or mineral sediment content. 3) Eutrophic- Meaning nutrient-rich refers to a lake condition that consists of high nutrients in the water column, low water clarity, and an over-abundance of algae and aquatic plants. 4) Mesotrophic- Meaning moderate nutrients refers to a lake with a moderate quantity of nutrients that allows the lake to have some eutrophic qualities while still having some nutrient-poor characteristics 5) Oligotrophic- Meaning low in nutrients or nutrient-poor refers to a lake with minimal nutrients to allow for only scarce growth of aquatic plant and algae life. Also associated with very clear waters. 6) Sedimentary Deposits- refers to the type of lake bottom sediments that are present. In some lakes, gravel and sand are prevalent. In others, organic muck, peat, and silt are more common. 19