Phosphorus Stressor in Lake Champlain Basin Alison Nord, Anna Speed, Ashley Murphy Classifying types of Phosphorus The 1993 Water Quality Agreement established in-lake total phosphorus concentration goals ranging from mg/l for 13 segments of Lake Champlain South Lake B (0.054) Otter Creek (0.014) Port Henry (0.014) South Lake A (0.025) Main Lake (0.010) Burlington Bay (0.014) Isle LaMotte (0.014) Shelburne Bay (0.014) Missisquoi Bay (0.025 ) St. Albans Bay (0.017) Cumberland Bay (0.014) Malletts Bay (0.010) Northeast Arm (0.014) Phosphorus concentrations criteria for various Lake segments LCBP recommended a mg/L phosphorus criterion in the Main Lake and Malletts Bay segments For the rest of the lake (except for St. Albans Bay, Missisquoi Bay, and the South Lake), an alternative phosphorus criterion of mg/L was suggested Missisquoi Bay and the South Lake segments: phosphorus criterion of mg/l (naturally eutrophic) Sources W/ Rankings Non-Point Sources Agricultural land (4) Urban (4) Point sources Waste Water treatment plants (1) Fisheries (.5) Industry (?) Non-Point Sources Non point sources = runoff from roads and developed areas, lawns, farmlands, and other rural areas Runoff from non-point sources contribute to more than 90% of the phosphorus in Lake Champlain Agriculture Rank = 4 in effects filter Agriculture = 14% of the Basins land area o contributes about 38% of the total nonpoint source phosphorus load to the Lake Major sources of agricultural phosphorus Urban Rank = 4 in the effects filter Urban and suburban land contribute up to 4x the phosphorus per unit area than either agricultural or forested land o Urban land constitutes 5% of the land use, yet it is estimated to contribute about 46% of the total phosphorus! 46% of nonpoint source phosphorus load is from urban land uses Point Sources of Phosphorus Point Sources are wastewater treatment plants and industrial discharges Due to reduction efforts, less than 10% of the phosphorus in the Lake comes from point sources Wastewater Treatment Plants Rank = 1 In general, maintained WWTP o Since 1996, over $28 million has been spent in the Lake Champlain Basin to upgrade phosphorus removal technologies at wastewater treatment plants. Fisheries Rank = 0.5 o has some effect, but not extremely important Little literature found regarding fisheries and input of phosphorus into lake Industry Not sure what is included in industry - WWTP and Fisheries already counted for Other industries could be paper mills... Discussion on Sources Matrix/Effects filter o How do we show that, while Ag and Urban are critical (4), urban has more of an impact per area? LCBP considers roads under urban sources & all data sets include roads under urban so it will be difficult to differentiate Need to weigh non-point more than point Would like to have data of watersheds broken down by land use o How do we incorporate land use differences? Much less urban land, but huge impact Habitats Lake Champlain o 6 - diluted enough that dont see big impacts? Lakes/Ponds other than Lake Champlain Rivers/Streams Wetlands Lake Champlain High impact by phosphorus Phosphorus encourages blue-green algae growth Some types of blue-green algae contain natural toxins that are released when these algae die and break down o Toxins are then released into the water creating a health concern Bacteria consume dissolved oxygen and kill off zooplankton, altering the food chain and eventually killing off fish species Recreation ceased during blue-green algae blooms Rivers/Streams High impact by phosphorus Non-point sources account for 76% of the total phosphorus load to watershed streams Surface erosion contributes to increased phosphorus loading into streams Change in stream channels = increased stream bank erosion Phosphorus in surface run off from agricultural fields = 41% of total load to streams in St. Albans Lakes/Ponds Medium impact by phosphorus Examples: Mirror Lake, Lake George, Saranac Lake In general, water consists of 7% of land cover within the basin Lakes contribute greatly to tourism, recreation, and as a water source for residents Wetlands Rank = 0.5 Consume P, act as sink - but very dependent upon vegetation type, water flow Can release phosphorus during storm events if too much phosphorus enters wetland Discussion on Habitats Several of the habitats are also sources of phosphorus o For our purposes, only considered habitats where phosphorus did not originate Need more work on Impacts filter Questions? Comments?