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MWC 2005 SPONSORS
U.S. Geological Survey . Senator George J. Mitchell Center . Maine DHS / Drinking Water Program . Portland Water District . Aqua Maine . Maine Coastal Program / State Planning Office . Maine Dept. of Environmental Protection . Maine Geological Survey . Maine Rural Water Association . Maine Wastewater Control Association . Maine Water Utilities Association . Maine Congress of Lake Associations . Maine Volunteer Lake Monitoring Program . Maine Rivers . University of Maine Cooperative Extension . Maine Sea Grant
State of Maine's Environment
Session Co-Chairs: Steve Kahl (Plymouth State University), Charlie Culbertson (USGS)
Catherine Rosfjord (student)1, Katherine Webster2, Steve Kahl3, Steve Norton4, and Ivan Fernandez5
1Senator George J. Mitchell Center for Environmental and Watershed Research, Orono, ME, 207/581-3233, catherine.rosfjord@umit.maine.edu
2Department of Biological Sciences, University of Maine, Orono, ME, 207/581-2542, katherine.webster@umit.maine.edu
3Center for the Environment, Plymouth State University, Plymouth, NH, 603/535-3180, jskahl@plymouth.edu
4Department of Earth Sciences and Climate Change Institute, University of Maine, Orono, ME, 207/581-2156, norton@maine.edu
5Department of Plant Soil and Environmental Science, University of Maine, Orono, ME, 207/581-2932, ivanjf@maine.edu
Are the Clean Air Act Amendments working? A 20 year re-evaluation of biologically relevant chemistry in Northeastern lakes
In 1984, the Environmental Protection Agency conducted the Eastern Lake Survey (ELS-I) to address the overall status of lakes in the east, with particular attention to acid deposition and pH. In 1986, a statistical subset of the ELS-I lakes, consisting of 145 lakes in the northeast, was re-sampled for ELS-II. Since the 1986 sampling, the Clean Air Act Amendment (CAAA) of 1990 mandated reductions in sulfate emissions with an intended result of increasing the pH of surface waters. In 2004, we re-sampled the 145 northeastern lakes on the 20th anniversary of their original sampling. Of particular interest are trends in base cation concentrations which contribute to the acid neutralizing capacity (ANC) of surface waters and buffer against acid inputs. The failure of pH to increase in low ANC lakes despite declines in acid deposition has been attributed to a concurrent decline in surface water base cation concentrations. While sensitive low ANC lakes have been closely studied over the past 20 years, the chemical trends in high ANC lakes are poorly understood. We hypothesize that waters with higher ANC and base cations are not experiencing a decline in base cations while the lower ANC lakes are experiencing a decline. This would indicate that while high ANC are buffered from acid inputs to the watershed, acid deposition is still affecting biologically relevant chemistry in low ANC lakes. Ultimately, this information will allow for assessment of the CAAA and its effectiveness in increasing pH in surface waters through reductions in sulfate emissions.
Kirsten Ness (student)1 , K.E. Webster2, and R.J. Bouchard3
1Senator George J. Mitchell Center for Environmental and Watershed Research, University of Maine, Orono ME, 207/581-3233, kirsten.ness@umit.maine.edu
2Department of Biological Sciences, University of Maine, Orono ME, 207/581-2542, katherine.webster@umit.maine.edu
3Maine Dept. of Environmental Protection, Augusta ME, 207/287-7798, roy.bouchard@maine.gov.
The effects of shoreline development on habitat complexity of lake littoral zones in Maine
Increasing pressures from residential shoreline development threaten to alter littoral habitats of lake ecosystems. Shoreland zoning regulations were instituted in 1971 by the State of Maine to control development and alterations of lake riparian zones; however, the amount of protection provided by these regulations has not been evaluated. Our first goal is to evaluate the natural condition and habitat complexity of littoral habitats in small to moderate size, headwater drainage lakes in Maine. The second goal is to determine how shoreline development affects littoral habitat complexity. Lake littoral habitats are highly heterogeneous due to factors such as substrate composition, slope, and wave action. Physical variables, such as slope, aspect, and substrate type (shoreline and littoral) are used to define the natural riparian/littoral physical template in lakes with little or no shoreline development. This site specific template allows us to create expectations for habitat complexity, which is defined as a function of macrophyte community structure and coarse woody debris. The natural template can be applied to developed lakes to assess differences in habitat complexity between natural and developed conditions. Biological response variables to habitat complexity include macroinvertebrate community and macrophyte species assemblages. Results indicate positive relationships between structural groups of macrophytes and sediment composition in both undeveloped and developed lakes. Lakes with shoreline development also have less coarse woody debris. Results will be used to identify possible indicators of habitat change and the effects of increasing shoreline development intensity on littoral habitat complexity.
Robert D. Dunlap1 and Richard C. Cook2
1University of Maine Professor Emeritus of Chemistry
2President of the Green Lake Association
The Connection Between Ice-Out and Hypolimnion Oxygen Data for Green Lake, Maine
A linear relation exists between hypolimnion oxygen concentrations and the length of time between ice-out dates and the dates when the oxygen concentrations were measured. Thirty eight independent determinations of oxygen concentrations obtained at Green Lake Sample Station 02 between 1942 and 2003 are represented by the equation: y = 13.8±0.3 - 0.064±0.003 x, where y = O2 (mg/L) and x is the number of days between the ice-out date and the measurement date. The Pearson linear regression coefficient is -0.95 and the standard error in the oxygen measurements is 0.5 mg/L.
When the lake stratifies in the summer, a quantity of oxygen is stranded in the hypolimnion layer. The rate at which hypolimnion oxygen decreases with time each summer is constant at 0.064 mg/L/day and is attributed to biological and chemical processes occurring in the lake. Our correlation allows us to compare hypolimnion oxygen concentrations measured at different times of the year, and with historic data.
The rate at which hypolimnion oxygen decreases depends on the mass of oxygen in the hypolimnion stratum and consequently on the depth of the lake. At Green Lake Sample Station 01, the water depth of 51 meters is more than twice that at Sample Station 02, and the rate at which the hypolimnion oxygen decreases is one third that observed at Station 02. The large mass of oxygen in the hypolimnion stratum at Station 01 almost completely buffers the effect of fluctuating ice cover on the oxygen concentrations observed at Sample Station 02.
Brad Caswell
Cherryfield Foods, Inc., Cherryfield, ME, bcaswell@tops-tele.com
APPLICATION OF SURFACE AND GROUND WATER INTERCONNECTION CONCEPTS TO BLUEBERRY IRRIGATION IN MAINE
Interconnection between surface and ground water has been understood since about 1700. There are many examples of using this knowledge to successfully manipulate the relationship for beneficial human purposes without harmful environmental consequences. Unfortunately there also are situations where this hydrogeologic understanding has not been applied to the development of municipal and other water supplies with the result that water availability has been less than anticipated and environment damages have occurred. New guidelines and regulations are addressing this oversight. One of the activities being so addressed in Maine is blueberry farming that uses large volumes of water for irrigation. Surface water sources were used initially, but streams and lakes have conflicting fisheries and recreational water demands. Wells are recognized as more favorable for blueberry irrigation so long as they can be located and operated to avoid adverse impact on surface water. Non-harmful irrigation wells are pumped only seasonally, and are located to take advantage of natural flow divides, perched surface water bodies, and confined aquifers.
Richard Behr1 and Troy Smith2
1Geologist, Maine Dept. of Environmental Protection, 207/287-2651, richard.behr@maine.gov
2Geologist, Maine Dept. of Environmental Protection, 207/287-2651, troy.t.smith@maine.gov
Easy to Use Equipment for Sampling Sediment Pore Water
A new tool allows investigators to collect pore water samples quickly and easily. Many contamination sites in Maine are located near surface water bodies. Typical site investigations rely on groundwater, surface water, and sediment sample results to determine potential risks posed to surface water bodies. In some cases, rock baskets are used to quantify the health of macroinvertebrate populations along stretches of surface water bodies adjacent to contamination sites. However, there is often little attention given to the mass flux of contaminants within the sediment pore water. Sediment pore water contamination can impact macroinvertebrate communities, surface water quality, sediment quality, and groundwater quality. Sediment pore water contamination can pose ecological and human health risks through contact and ingestion pathways. Surface water and sediment samples do not quantify the potential mass transfer of contaminants from groundwater to surface water. Push PointT groundwater/surface water interface sampling devices are very useful in collecting sediment pore water. Field parameters such as dissolved oxygen (DO), oxidation-reduction potential (ORP), specific conductance (Conductivity), pH, and turbidity can be used to help identify areas for laboratory sample collection. MEDEP personnel have used Push Point Samplers to collect pore water samples and groundwater seep samples. Sample results have shown significant contamination in pore water samples and seep samples that more traditional methods have not identified. This technique has been applied to petroleum, hazardous substance, and landfill sites. This presentation provides an opportunity to see Push Point Samplers and sample results from various sampling events in Maine.
Dave Halliwell
Maine Dept. of Environmental Protection, Augusta, ME, 207/287-7649, david.halliwell@maine.gov
White perch distribution, ecology, and management in estuarine and fresh waters
White perch (Morone americana) are native to brackish coastal ponds and estuaries along the Atlantic coast from Nova Scotia to South Carolina. Historically introduced populations are now landlocked in numerous inland lakes and ponds throughout New England as a result of past stockings by fishery managers and unauthorized transplants. In Maine, white perch are very popular and "may be the most often illegally introduced species." They are generally abundant and easily angled by youngsters - while larger (humpback) individuals are eagerly sought after for human consumption. The name white perch is confusing, as they are not really 'perch' per se, but are members of the sea-bass family - closely related to striped bass. In lakes, adults stay in deeper water during the summer - when schools of juveniles inhabit lake shores, "feeding voraciously on very small planktonic water insects (zooplankton) during the evening hours." White perch feed year-round, except shortly prior to and during spawning, which occurs in early summer (May-June). They are a prolific species (up to 250,000 eggs per female) and can be a problem fish in many freshwaters, where they tend to overpopulate and stunt - tying up a substantial portion of the food supply while providing minimal fishing opportunity. Given the presence of a large biomass of white perch in many nutrient enriched nuisance algal blooming lakes in Maine, it is hypothesized that their dominance is detrimental to water clarity. Lake biomanipulation studies are underway to investigate lake trophic relationships within select phosphorus-load mitigated watersheds.
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