Dissolved oxygen measures the available oxygen within the water column for fish, macro invertebrate and other aquatic life. The dissolved oxygen levels have a direct relationship with fish recruitment, zooplankton and mussels. For example trout require at least 6mg/L whereas bass require 5mg/L and carp can survive at 1mg/L. Dissolved oxygen is influenced by wave action, water temperature, light penetration, amount of oxygen used for respiration and decomposition processes ( University of Wisconsin 2006).
A 2 degree (Celsius) change (increase) in water temperature can change an entire lake’s biodiversity of fish species in addition to algal growth(Casselman 2013, CHA Spring Lake Stewards Meeting).
Secchi disk :
Measures the turbidity in the water column (indication of suspended particles and algae within the water column (MOE, Lake Partner Program).
TP: Total phosphorus.
Measures the quantity of inorganic and organic inputs. Phosphorus occurs naturally in the environment and is needed by plants and animal to grow. When a plant or animals die the phosphorus is released and can enter a water body. In high levels it can impact a water body negatively and encourage algal blooms. Phosphorus is also found in human and animal excrement (i.e., faulty septic tanks) and is a nutrient that controls the growth of algae and aquatic plants in freshwater ecosystems.
Provincial water quality guidelines indicate that to avoid nuisance algal blooms phosphorus concentrations should be lower than 20µg/L in lakes during the ice free period and not below 30 µg/L in rivers (MOE 1999).
Calcium (2013)(Data to be released 2014)
Calcium is necessary for various types of zooplankton and larger invertebrates like crayfish, gastropods, and clams. Canadian Shield lakes are experiencing a decline in calcium levels as result of previous years of acid rain, a reduction of the replenishment of calcium from soil due to forest harvesting practices and as a result of climate change (DESC 2013).
Measures the acidity/alkalinity of the water
Conductivity in water is affected by the presence of inorganic dissolved solids such as chloride, nitrate, sulfate, and phosphate anions (ions that carry a negative charge) or sodium, magnesium, calcium, iron, and aluminum cations (ions that carry a positive charge). Conductivity is also affected by temperature: the warmer the water, the higher the conductivity. (EPA 2014). The measurement of conductivity can be an indicator to a non nutrient potential pollutant.