Presentation on theme: "The State of Deep Creek Lake, 2012 Second Annual State of Deep Creek Lake, 2012 14 November 2012 John R. Griffin, Secretary Maryland Department of Natural."— Presentation transcript:
The State of Deep Creek Lake, 2012 Second Annual State of Deep Creek Lake, 2012 14 November 2012 John R. Griffin, Secretary Maryland Department of Natural Resources
The State of Deep Creek Lake, 2012 Introduction Secretary John R. Griffin MD Department of Natural Resources
The State of Deep Creek Lake, 2012 to protect the lake as a man-made resource, preserve its ecological balance, and maintain its use as a recreational and economic asset. Goals for Deep Creek Lake
The State of Deep Creek Lake, 2012 The state of Deep Creek Lake today is that of a healthy reservoir that meets most users needs under the federal Clean Water Act… Good water quality Diverse plant and animal life Moderate levels of nutrients to support aquatic life Even so… the lake has its share of issues…
The State of Deep Creek Lake, 2012 Water Quality Bruce Michael Director, Resource Assessment Service MD Department of Natural Resources
The State of Deep Creek Lake, 2012 Water quality monitoring goals : characterize existing water quality conditions in the lake and its tributary coves – physical and chemical characteristics, levels of nutrients and primary productivity establish baseline conditions to evaluate trends in water quality conditions monitor water quality conditions at tributary stream gage sites to eventually determine nutrients and sediment loads entering the lake from the watershed
The current monitoring program has defined seasonal and spatial variations and established a baseline of conditions to evaluate how changes in population/land use in the watershed affect Deep Creek Lake. Deep Creek Lake has a diverse aquatic plant community with a wide range of species ranging from microscopic phytoplankton species to vascular aquatic plants, including invasive species. Weather conditions (temperatures/precipitation) have varied each year during the summer, which can affect some measures… 2009 - cool, moderately dry summer 2010 – very warm, dry summer 2011 - very warm, wet summer 2012 - hot, moderately dry summer Monitoring Summary
The State of Deep Creek Lake, 2012 2012 Monitoring Results Water temperatures in summer 2012 were highest recorded during this monitoring period (2009-2012). Oxygen levels in the upper waters of the lake, pH, conductivity, and nutrients (nitrogen and phosphorus) are at levels that support a diverse biological community (plankton, aquatic plants, fish and wildlife). Algal levels are limited by the low concentrations of phosphorus in the lake. Open waters are very clear and support swimming, boating and growth of aquatic plants in deeper waters
The State of Deep Creek Lake, 2012 Health advisory to limit consumption of bass and walleye caught in the lake due to elevated mercury. This is a Statewide concern in many lakes. Summer oxygen levels in the cool, deep portions of the lake (greater than 21-34 feet) are too low (< 2 ppm; hypoxic) to support aquatic life. This is naturally occurring but increases in nutrients to the lake = increases in algae = longer hypoxic periods and occurrences in more shallow areas of the lake. Water Quality Issues
The State of Deep Creek Lake, 2012 Water Quality Trends, 1970-2012 Long-term trends in lake productivity (measured as the amount of chlorophyll in microscopic phytoplankton) show little change and indicates that phosphorus levels have not appreciably increased. nutrient polluted nutrient enriched moderate nutrients supports diverse aquatic life nutrient poor
The State of Deep Creek Lake, 2012 Water Quality Trends, 1970-2012 Long term trends in electrical conductivity in the lake (a measure of input of dissolved salts in fertilizers, septage, and deicer chemicals from the watershed) have doubled but are not yet at levels that impact aquatic life.
The State of Deep Creek Lake, 2012 Aquatic Vegetation
The State of Deep Creek Lake, 2012 Locations of DNRs Aquatic Vegetation survey transects, 2010-2012
The State of Deep Creek Lake, 2012 2012 EWM shoreline survey summary – I 86 acres of Eurasian water milfoil (EWM) were mapped in a complete shoreline survey conducted July 9-10, 2012 –2.3% of the lake surface –5.8% of shallow (less than 6m deep) water –EWM co-occurred with other SAV species Northwest half of Deep Creek Lake
The State of Deep Creek Lake, 2012 2012 EWM shoreline survey summary - II Transect data indicate no significant difference in percent cover of EWM between 2010, 2011 and/or 2012 Seen from the surface, other native submerged grasses are far more common, specifically Potamogetons and Vallisneria, which occupy virtually all of the lake shallows Southeast half of Deep Creek Lake
The State of Deep Creek Lake, 2012 Control options for EWM Most effective / lowest impact large scale (acres) control option is the use of herbicide 2,4-D (repeated application necessary over years) Cost of $500 to $1000/acre Can be used in spot treatments Low toxicity to most fish (some salts are highly toxic to trout), but might be an endocrine disruptor to aquatic vertebrates Localized control measures include benthic barriers or hand removal Care must be used to capture all hand-harvested removal to minimize spread Benthic barriers are expensive per unit area (4 installations in 2012; $300- 500/mat – cost, install, removal), but very effective Hand removal is inexpensive and very low impact, but is inefficient Mechanical harvesting Expensive ($8-10,000 for two days) Risk of spreading EWM from fragments or introducing other SAV species carried in on equipment from other water bodies
The State of Deep Creek Lake, 2012 EWM Control options rejected / reasons Herbicides other than 2,4-D Some impacts to other SAV species and/or fish Less effective in DCL – due to the large lake volume ($300-500/acre) Biological controls Grass carp are illegal in Maryland Milfoil weevils havent been approved for importation into the state by Invasive Species Matrix Team –Risk of escape into Chesapeake / other waterbodies Very expensive ($1,000s per acre) –Efficacy uncertain in Deep Creek Lake –In other regions, EWM control is very slow –Controls are vulnerable to sunfish predation - DCL has a lot of sunfish
The State of Deep Creek Lake, 2012 Going forward… Continue transect surveys at 6 locations in the lake (3 times per year) Monitor / assess Eurasian water milfoil –Complete statistical analyses –Conduct 2 nd targeted EWM survey in June 2013 Implement pilot control actions –Monitor results to guide future actions
The State of Deep Creek Lake, 2012 Pilot project proposed to evaluate effectiveness of EWM control measures in selected Deep Creek Lake sites –Herbicide (2,4-D) control – location TBD –Harvest of limited areas – location TBD
The State of Deep Creek Lake, 2012 Sedimentation Phase II – DCL Sediment Plan
The State of Deep Creek Lake, 2012 Lake Sediments - Completed Field Work April 2012 - Field Work –Sub-bottom seismic survey and bathymetry collected along transects throughout the lake. –Complete sidescan sonar imagery of the lake and GPS-referenced shoreline video inventory May-September 2012 - Data processing / analysis –QA/QC and processing/correcting and interpretation of data results –Identify areas of sedimentation / no sedimentation using sidescan imagery, bathymetric comparisons, and sub-bottom seismic data. October 2012 – Field Work –Collected 42 sediment cores throughout lake and analyzed selected cores and deposited sediment for chemicals and pollutants. All samples were determined and documented to have no pollutants at detectable and reportable levels. –Alternatives Analysis and Sediment Reduction contracts have been written and are awaiting the bidding process.
The State of Deep Creek Lake, 2012 Sub-Bottom Seismic/Bathymetry Survey Coverage
The State of Deep Creek Lake, 2012 Sediment Cores –42 Cores collected throughout lake –Core lengths ranged from 0 (Rock confirmation) to 7 feet in length. The average collected length of each core was 3 feet. –Cores were described, photographed, and sampled. Select samples are being analyzed for pollutants, chemical properties, and physical properties.
The State of Deep Creek Lake, 2012 Future Plan November 2012 – May 2013 –Complete analysis of sedimentation within the Lake and publish a comprehensive report (February 2013) –Contractors will develop a sediment reduction plan to be provided to state and local governments and landowners. (May 2013) –Contractors will develop an alternatives analysis determining if dredging is recommended. If so, they will identify costs, methods, and impacts.
The State of Deep Creek Lake, 2012 Status of the Fishery Remember that: in summer 2010, about 10,000 fish died in the lake from a bacterial infection. Yellow perch, Walleye, and Smallmouth bass were most affected.
The State of Deep Creek Lake, 2012 Spring 2012 Walleye Survey Walleye are the most abundant game fish species in the Deep Creek Lake with diverse size classes including trophy-sized fish over 20 inches long. The 2012 adult walleye abundance value was one of the highest recorded to date in Deep Creek Lake.
The State of Deep Creek Lake, 2012 Also in Spring 2012… Maryland DNR Fisheries Service conducted a corrective stocking of 10,000 fingerling Largemouth Bass. These were stocked at several locations in Deep Creek Lake in response to losses from the 2010 fish kill event.
The State of Deep Creek Lake, 2012 Summer 2012 – Conducted seining surveys to monitor reproductive success for Largemouth Bass, Smallmouth Bass, and Yellow Perch. Reproductive success in 2012 was rated as: - Good for Largemouth Bass; - Excellent for Smallmouth Bass; and - Excellent for Yellow Perch
The State of Deep Creek Lake, 2012 Summer – Fall 2012: MD DNR Fisheries Service obtained length, weight, and angler catch data during bass tournaments held on Deep Creek Lake. Analysis of these data have not been completed, but size of fish and catch rates among anglers appear to have improved since the 2010 fish kill event.
The State of Deep Creek Lake, 2012 Fall 2012 – Comprehensive Fish Population Survey - scheduled for Oct. 31, but delayed by some snow on the ground…
The State of Deep Creek Lake, 2012 Lake Water Levels John Grace Water Management Administration MD Department of the Environment
The State of Deep Creek Lake, 2012 Uses of the Lake Deputy Secretary Joe Gill MD Department of Natural Resources
The State of Deep Creek Lake, 2012 5,300 boats, including 600 PWCs Trend - bigger boats, e.g., 26-foot boat with molded platform Trend – wider, longer piers Wake-boarding Recent regulatory changes –Limits on powerboats –Limits on wakeboarding Boating
The State of Deep Creek Lake, 2012 Carrying capacity 2003 study – tolerance to crowding on the surface of the Lake by various types of recreational boating activity No study on maximum build-out of dock slips on the Lake Boating
The State of Deep Creek Lake, 2012 Marinas Mini-marina requirements Impact to Deep Creek Lake -Town Center -Town Residential -Assessment Illustrates need to manage shoreline in concert with the Lake Illustrates larger need to manage watershed
The State of Deep Creek Lake, 2012 Lake / Watershed Management Secretary John R. Griffin MD Department of Natural Resources
The State of Deep Creek Lake, 2012 A lake is a reflection of its watershed… DNR manages only a small portion of the Deep Creek Lake watershed - mostly the lake and buffer areas at the end of each sub-watershed. Private holdings make up most of the watershed. As land use changes occur in the watershed, characteristics of the lake also will change. Addressing stresses in the watershed will slow changes in the quality of the lake and will maintain current conditions for this important asset for the county and State. Image source: Chesapeake EcoCheck. 2011. Deep Creek Lake baseline condition assessment. 4p. Online at: http://www.eco-check.org http://www.eco-check.org
The State of Deep Creek Lake, 2012 Our greatest collective challenge… To take a watershed approach to future lake management.
The State of Deep Creek Lake, 2012 Individual Testimony