Lake Water Quality 2006 Report - Lakefield Herald

sites for both lakes (Pigeon Lake S and Sturgeon Lake S) have historically had higherconcentrations of total phosphorus. Stony Lake typically has lower phosphorusconcentrations and Lovesick Lake higher concentrations relative to the otherKawartha Lakes. Other researchers have had conflicting results using epiphytebiomass as an indicator of phosphorus concentrations in lakes, but there is someevidence that suggests that it can be a fairly good indicator of localized sources ofnutrients.Sampling was carried out during the first week of September, which is the time whenthis particular community can be found in its greatest abundance.Table 1. Location of sampling sites across the Kawartha Lakes.Pigeon Lake SPigeon Lake CPigeon Lake NSturgeon Lake SSturgeon Lake CSturgeon Lake NLovesick Lake 1Lovesick Lake 2Lovesick Lake 3Stony Lake 1Stony Lake 2Stony Lake 3Emily Provincial ParkGannon's NarrowsOliver Ecological CentreSnug Harbour MarinaGreenhurst ThurstoniaBirch PointMcCallum’s IslandArdagh Cottage ResortFeathers IslandNorthey's Bay Rd - public boat launchoff FR 26 (off Northey's)Viamede ResortTable 1 shows the location of sampling sites that were visited for this year’sassessment of epiphyton and metaphyton biomass. We chose sites that were similarwith respect to turbulent energy (i.e., the degree of exposure to wind and waveactivity), macrophyte community and bottom sediment characteristics. Sampling at allsites occurred at a water depth of approximately 1 m. For determination of algalbiomass on the shoots of two species, we harvested the top 25 cm of intact shoots,placed them into a container of clean water and agitated the container. We thendetermined the amount of algae as indicated by chlorophyll a (an important plantpigment involved in photosynthesis) that was left in the water and used this as asurrogate for the total biomass of algae that was present on the shoots. Harvestedmacrophyte shoots were then dried in an oven and weighed. You’ll notice that wepresent the data in units of µg chl a /g dry wt [micrograms of chlorophyll a per gramof dry weight]. This allows us to standardize the amount of attached algae per unit ofdry weight biomass of macrophyte. We also determined the amount of suspended47