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Aquatic Macrophyte Survey with Remediation Suggestions for Best Hills Ranch. Brad Kalb Tyson Fehringer Marie Pengilly Kristen Pilcher Montana Skovlin John Schisel Tim Barbier. Objectives. Estimate amount of aquatic vegetation in the lake Estimate phosphorus in the lake
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Aquatic Macrophyte Survey with Remediation Suggestions for Best Hills Ranch Brad Kalb Tyson Fehringer Marie Pengilly Kristen Pilcher Montana Skovlin John Schisel Tim Barbier
Objectives • Estimate amount of aquatic vegetation in the lake • Estimate phosphorus in the lake • Estimate phosphorus stored in the plants • Explore options for remediation • Cost efficient • Reduce aquatic vegetation
Study Site • Best Hill Ranch, Coeur d’Alene, Idaho • Sampled October 7 and 14, 2009
Methods • Aquatic vegetation • Collected from 14 areas • Macrophyte sampler • Dried in oven for 48 hours • Weighed • Analyzed for phosphorus
Results • Aquatic vegetation • ~2,700 kg (~6,000 lbs) dry mass for entire lake • ~93 kg (~205lbs) phosphorus in the plants
Discussion • Estimated 659 kilograms (~1,500 lbs) total phosphorus in sediment • Plants are storing large amounts of phosphorus • Summer pump is only adding 23 grams (0.05 lbs) • Most of the phosphorus most be coming from runoff
Remediation • Physical removal • Harvest in a striped pattern • Raking and hand pulling • Harvest when growth is at its highest • 160 hours of work • ~$2,000 annually
Remedation • Use strips to keep the sediment down and the water clear • Removing plants could cause an algae bloom • Use chemicals to keep algae down
Macrophyte Remediation • Chemicals • Aquashade • $70 for a gallon bottle • 4 bottles • $280 annually
Our Recommendation • Decrease nutrient loading • Manual removal of macrophytes • Long term removal of nutrients from system