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Moos M.T.,Lake Simcoe Region Conservation Authority | Taffs K.H.,Southern Cross University of Australia | Longstaff B.J.,Lake Simcoe Region Conservation Authority | Ginn B.K.,Lake Simcoe Region Conservation Authority
Journal of Environmental Management | Year: 2014

Innovative management strategies for nutrient enrichment of freshwater are important in the face of this increasing global problem, however many strategies are not assessed over long enough time periods to establish effectiveness. Paleolimnological techniques using diatoms as biological indicators were utilized to establish ecological reference conditions, environmental variation, and the effectiveness of lanthanum-saturated bentonite clay (brand name: Phoslock®) applied to reduce water column phosphorus (P) concentrations in four waterbodies in Ontario, Canada, and eastern Australia. In sediment cores from the two Canadian sites, there were short-lived changes to diatom assemblages, relative to inferred background conditions, and a temporary reduction in both measured and diatom-inferred total phosphorus (TP) before returning to pre-application conditions (particularly in the urban stormwater management pond which has a high flushing rate and responds rapidly to precipitation and surface run-off). The two Australian sites (a sewage treatment pond and a shallow recreational lake), recorded no reduction in diatom-inferred TP. Based on our pre-application environmental reconstruction, changes to the diatom assemblages and diatom-inferred TP appeared to be driven by larger, climatic factors. While laboratory tests involving this product showed sharp reductions in water column TP, management strategies require detailed information on pre-application environmental conditions and variations in order to accurately assess the effectiveness of new technologies for lake management. © 2014 Elsevier Ltd.


Winter J.G.,Environment Canada | Landre A.,Environment Canada | Lembcke D.,Lake Simcoe Region Conservation Authority | O'Connor E.M.,Lake Simcoe Region Conservation Authority | Young J.D.,Environment Canada
Water Quality Research Journal of Canada | Year: 2011

Chloride concentrations in Lake Simcoe have increased significantly (P<0.001) over a 36-year period during which the human population in the watershed has grown. Lake concentrations are now between 36 and 40 mg/L, having increased more than three-fold at the lake's outflow since 1971. Concentrations increased significantly in eight tributaries of the lake from 1993 to 2007 (P<0.05), and were highest in those rivers draining the greatest percentage of urban land and roads, and in a river close to a major highway. The cumulative chloride load estimated at the mouths of seven rivers flowing into Lake Simcoe ranged from 11,563 to 32,107 tonnes/year from 1998 to 2007, and increased significantly over this period (P<0.05). The fluxes or unit area loads of chloride, averaged from 2004 to 2007 for each of 10 tributaries, were positively correlated with the proportion of urban land and roads drained (P1/4 0.005, r 1/4 0.80). Although Lake Simcoe is a large lake and only 12% of its watershed drains urban land and roads, evidence of road salt application can already be seen. This indicates that inputs must be reduced to preclude future ecological impacts on the lake. © Crown Copyright 2011.


Nurnberg G.K.,Freshwater Research | Molot L.A.,York University | O'Connor E.,Lake Simcoe Region Conservation Authority | Jarjanazi H.,Environment Canada | And 2 more authors.
Journal of Great Lakes Research | Year: 2013

Hypoxia and cyanobacterial blooms were extensive in Lake Simcoe during the 1980s and are still a problem to a lesser degree despite extensive nutrient load reduction from the catchment basin. The continuing signs of productivity indicate a potential internal phosphorus (P) source. Internal P load, as a redox-dependent release from bottom sediments, is hard to determine in a large, relatively shallow and partially unstratified lake such as Lake Simcoe. Of the lake's three major basins, only Kempenfelt Bay stratifies long enough to develop hypoxia in the stagnant summer hypolimnion. The following indications of sediment P release are available from historic data: 1) hypolimnetic hypoxia still occurs in Kempenfelt Bay although the hypoxic factor (number of days that an area equal to the bay's surface area is overlain by water of ≤. 2. mg/L dissolved oxygen, DO) has decreased substantially and significantly from 15.8. d/yr (1980-1994) to 4.0. d/yr (1995-2011); 2) hypoxic factors for other lake sections and at different DO levels also indicate widespread hypoxia; 3) concentrations of redox dependent metals, Fe and Mn, increase with depth; and 4) euphotic zone P and chlorophyll concentrations increase and water clarity decreases during fall turnover. Cyanobacterial blooms appear to occur in response to internal load as supported by occasional cyanobacteria counts. These indicators provide evidence that internal loading is likely occurring and affecting the water quality in Lake Simcoe. We expect that further monitoring, specific for internal load, will corroborate these results. © 2013 Elsevier B.V.


Loh P.S.,York University | Molot L.A.,York University | Nurnberg G.K.,Freshwater Research | Watson S.B.,National Water Research Institute | Ginn B.,Lake Simcoe Region Conservation Authority
Inland Waters | Year: 2013

This study evaluated phosphorus (P) and iron (Fe) release from anoxic sediment cores in 3 different water bodies, Lake Winnipeg in Manitoba and Lake Simcoe and Hamilton Harbour in Ontario, and developed empirical models to predict P and Fe release rates as functions of sediment and water chemistry. Maximum P and Fe sediment release rates, which occurred shortly after sulfate (SO4) was depleted in most cores, showed unique positive linear relationships for each lake. High P release rates only occurred from Lake Simcoe and Lake Winnipeg sediments with molar ratios ≤8.1 of NaOH-extractable aluminum (Al) to reducible Fe (Fe extractable with bicarbonate-dithionite [BD]). High Fe release rates only occurred in Lake Winnipeg sediments, perhaps due to low SO4 reduction rates (<115 mg m-2 d-1). Three approaches were used to develop linear regression models for maximum P and Fe release rates using data from all lakes: only Lake Winnipeg, only Lake Simcoe, and low (≤8.1) and high molar ratios (>20) of NaOH-extractable Al to BD-extractable Fe. Regression models differed depending on the study sites used, and only 3 of the 5 significant regression models for P release had high predictive value (R2 > 0.7). Four of the 5 significant Fe release models had R2 > 0.7, but we were unable to find a significant Fe model for Lake Simcoe. These results are important because they delineate the limitations of this approach to modeling release using operationally defined fractions. © Her Majesty the Queen in Right of Canada, as represented by Environment Canada 2013.


Ozersky T.,Ontario Ministry of Natural Resources | Ozersky T.,University of Minnesota | Evans D.O.,Ontario Ministry of Natural Resources | Ginn B.K.,Lake Simcoe Region Conservation Authority
Freshwater Biology | Year: 2015

This study examined the effect of invasive dreissenid mussels on nutrient and carbon dynamics in a large lake (Lake Simcoe, Ontario). We measured rates of nutrient (phosphorus and nitrogen) and carbon excretion and biodeposition by zebra and quagga mussels and the P, N and C content of their soft tissues and shells at different depths throughout the open-water season. Measurements were combined with detailed information about dreissenid biomass and lakewide distribution to examine the impacts of dreissenids on whole-lake dynamics of P, N and C. Mussel tissue P, N and C content and rates of excretion and biodepositon varied among species, seasons and depths, apparently driven by metabolic and stoichiometric factors. Dreissenid mussels excreted, deposited and stored large quantities of P, N and C when compared to lake standing stocks and loadings, and represent an important driver of nutrient cycling in the lake. Living and discarded mussel shell material is shown to represent a potentially important, and hitherto largely overlooked, long-term sink for P, N and C. The concentration of dreissenid biomass in the well-mixed and illuminated littoral portion of L. Simcoe results in redirection of nutrients and carbon from offshore areas to the nearshore zone of the lake. Changes in nutrient and carbon distribution and cycling patterns caused by dreissenid establishment in L. Simcoe and other ecosystems can have implications for the distribution of primary and secondary production and should be considered in the context of water quality and nutrient input management. © 2015 John Wiley & Sons Ltd.


Lembcke D.,Lake Simcoe Region Conservation Authority | Ansell A.,Lake Simcoe Region Conservation Authority | McConnell C.,Lake Simcoe Region Conservation Authority | Ginn B.,Lake Simcoe Region Conservation Authority
Journal of Great Lakes Research | Year: 2011

In 2004 the Lake Simcoe Region Conservation Authority (LSRCA) initiated a sampling program to examine historic and emerging contaminants throughout the Lake Simcoe watershed. Through the sampling program it was determined that Dichlorodiphenyltrichloroethane (DDT) concentrations in sediment were exceeding the Canadian Environmental Quality Guidelines just downstream of the Holland Marsh. The objective of this study was to investigate the presence of DDT in the waters surrounding the Holland Marsh and examine if the concentrations sampled represented a potential threat to aquatic and terrestrial biota in the Holland Marsh environs. Semipermeable membrane devices were used to determine DDT concentrations at different locations within the Holland Marsh and surrounding waters for a month in 2006, 2007 and 2008. DDT concentrations were compared to fish tissue guidelines where it was found that some sections of the Marsh experience concentrations which have the potential to impact the health of biota in the immediate area. Varying weather conditions between study years revealed the importance of precipitation in transporting DDT through the marsh. Precipitation above or equaling long-term normals occurred in 2006 and 2008 which coincided with higher DDT concentrations than the significantly drier year of 2007. The information gained in this study will play a valuable role for both terrestrial and aquatic ecosystem managers in understanding how historic DDT use in the Holland Marsh may still be affecting this environment and Lake Simcoe today. © 2011 Elsevier B.V.


Species composition, distribution, and biomass of submerged aquatic plants were studied in Lake Simcoe (Ontario, Canada) as was the use of macrophytes as indicators of lake trophic status. While previous studies in this lake targeted one eutrophic embayment, this study covered the entire lake area, identified five areas of high plant biomass and recorded 16 macrophyte species; the community was dominated by Ceratophyllum demersum (39.1% of the total biomass), the invasive species Myriophyllum spicatum (27.4%), Elodea canadensis (10.7%) and Chara spp. (9.7%). Canonical correspondence analysis (CCA) identified four significant limnological variables related to plant biomass: (a) depth, likely a proxy for light levels; (b) substrate type, related to nutrient availability, stability, and wave exposure; (c) phosphorus loading from the closest tributary; and (d) size of the area drained by a tributary. Since initial (1971) macrophyte surveys on Lake Simcoe, the community has been dramatically altered by expansion of an invasive species (i.e. M. spicatum) resulting in declines of native shallow-water species (e.g. Chara spp.). The arrival of zebra mussels (Dreissenia polymorpha) ~1995 and reductions in phosphorus loading have increased water clarity, extending the maximum depth of plant colonization (6.0m in 1984 to 10.5m in 2008), and almost tripled macrophyte biomass (1.2kg·m-2 in 1984 to 3.1kg·m-2 in 2008). Increased plant biomass, and a loss of species diversity due to spread of M. spicatum are interpreted by macrophyte indices as a decrease in lake trophic status, which likely explains why these indices did not follow trends in reduced phosphorus loading. © 2011 International Association for Great Lakes Research.


Thompson B.,Lake Simcoe Region Conservation Authority
Environmental Management | Year: 2015

Recreational disturbance associated with trails has been identified as one of the major factors causing a decline of native biodiversity within protected areas. However, despite the negative impacts that recreation can have on biodiversity, providing public access to nature is critical for the future of the conservation of biodiversity. As such, many protected area managers are looking for tools to help maintain a balance between public access and biodiversity conservation. The objectives of this study were to examine the impacts of recreational trails on forest-dwelling bird communities in eastern North America, identify functional guilds which are particularly sensitive to recreational trails, and derive guidelines for trail design to assist in managing the impacts of recreational trails on forest-dwelling birds. Trails within 24 publicly owned natural areas were mapped, and breeding bird communities were described with the use of point count surveys. The density of forest birds, particularly of those species which nest or forage on the ground, were significantly positively influenced by the amount of trail-free refuge habitat. Although management options to control trail use in non-staffed protected areas are limited, this study suggests that protected area managers could design and maintain a trail network that would minimize impacts on resident wildlife, while providing recreational opportunities for visitors, by designing their trail network to maximize the area of trail-free habitat. © 2015, Springer Science+Business Media New York.


Moos M.T.,Lake Simcoe Region Conservation Authority | Ginn B.K.,Lake Simcoe Region Conservation Authority
Lake and Reservoir Management | Year: 2016

Moos MT, Ginn BK. 2016. Developing a lake management strategy by dovetailing lake monitoring with paleolimnological techniques: a case study from a kettle lake on the Oak Ridges Moraine (Ontario, Canada). Lake Reserv Manage. 32: 234–245. In response to concerns about declining water quality, increased aquatic plant biomass, and harmful algal blooms, a lake monitoring program was undertaken on a suburban kettle lake near Toronto, Canada. We identified environmental conditions consistent with eutrophication, and the largest source of phosphorus (P) loading was from sediment release during an extended period of low dissolved oxygen during thermal stratification of the water column. To put these current environmental conditions in perspective, account for long-term limnological trends, and develop a sustainable lake management strategy, we also undertook paleolimnological analysis of a sediment core. Using diatoms as proxy indicators, historic limnological conditions were reconstructed. Although pre-European settlement conditions were typical of lakes with forested catchments in this region, the lake was mesotrophic (total phosphorus [TP] ∼17.5 µg/L), likely from P bound to dissolved organic carbon. P concentrations increased with the use of chemical fertilizers and establishment of seasonal lakeside cottages and resorts starting in the 1920s (the beginning of the diatom-inferred (DI-) TP upward trend). With the conversion of these cottages into year-round homes (since 1960) and further urbanization of the catchment, including servicing with municipal water supply but continued reliance on septic tanks, P has increased further (TP ∼26.1 µg/L). For restoration to a sustainable state, methods of preventing sediment P release (capping the sediment surface or oxygenation of the hypolimnion) should be considered, along with installation of municipal wasterwater servicing and stewardship projects to prevent further P loading from septic systems and surface runoff. © 2016, © Copyright by the North American Lake Management Society 2016.


PubMed | Lake Simcoe Region Conservation Authority
Type: Journal Article | Journal: Environmental management | Year: 2015

Recreational disturbance associated with trails has been identified as one of the major factors causing a decline of native biodiversity within protected areas. However, despite the negative impacts that recreation can have on biodiversity, providing public access to nature is critical for the future of the conservation of biodiversity. As such, many protected area managers are looking for tools to help maintain a balance between public access and biodiversity conservation. The objectives of this study were to examine the impacts of recreational trails on forest-dwelling bird communities in eastern North America, identify functional guilds which are particularly sensitive to recreational trails, and derive guidelines for trail design to assist in managing the impacts of recreational trails on forest-dwelling birds. Trails within 24 publicly owned natural areas were mapped, and breeding bird communities were described with the use of point count surveys. The density of forest birds, particularly of those species which nest or forage on the ground, were significantly positively influenced by the amount of trail-free refuge habitat. Although management options to control trail use in non-staffed protected areas are limited, this study suggests that protected area managers could design and maintain a trail network that would minimize impacts on resident wildlife, while providing recreational opportunities for visitors, by designing their trail network to maximize the area of trail-free habitat.

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