Involved Communities
Resources and Reports
Volunteer Handbook & Resources
|
Glossary
AllochthonousMaterial found in aquatic ecosystems that originated elsewhere in the watershed (Cole, 1994). Often, allochthonous and dystrophic are both used to describe tea-coloured lakes, which are dominated by organic carbon. These lakes are on a dystrophic scale, meaning clarity is not determined by phytoplankton growth (Clark, 2002a)
AutochthonousMaterial that is internally manufactured within the aquatic ecosystem (Cole, 1994). Autochthonous, or oligotrophic lakes are clear with low colour. Autochthonous lakes can be assigned a trophic status based on total phosphorus loading (Clark, 2002a)
BenthicAssociated with the bottom regions of a lake (Cole, 1994)
Benthic CommunityFound below the pelagic zone and downslope from the littoral zone. Organisms are supported by detritus and associated decomposers (Cole, 1994).
Benthic Organism(or Benthos) Plant or animal that lives at or near the bottom of a lake, river, stream or ocean (Henry and Heinke, 1996)
BlackwaterHousehold effluent used for sewage removal (Scheifer, 2001)
ColiformA large group of gram-negative, facultative bacteria (Madigan et al, 2000)
Compensation PointDepth at which light is reduced to 1% of its surface intensity, and is effectively undetectable. Plants cannot grow below the Compensation Point (Henry and Heinke, 1996)
CopropelSediments found in the profundal zone, rich in organics derived from plankton (rich in faeces) (Cole, 1994)
DimicticHolomictic lakes that experience two mixing periods (vernal and autumnal) (Cole, 1994). Larger lakes such as Lakes Rosseau, Joseph and Muskoka are dimictic. Thermal stability (stratification) is attained in the winter and summer, with full-watemass mixing achieved in the spring and fall.
DystrophyLake type featuring acidic, stained-brown water, low in electrolytes and with reduced transparency due to colloidal and dissolved hummus. Calcium deficiency blocks bacterial action and therefore organic material does not decay. Many dystrophic lakes are in fact oligotrophic due to lack of nutrients, plankton and algal flora despite low dissolved oxygen and low biodiversity (Cole, 1994).
Dystrophic Sediments(or Dy pronounced D¨¹) Are similar to copropel sediments but are acidic and high in carbon. May form yellow-brown fiberous plant-like material (Cole, 1994).
EpidemiologyThe study of the occurrence, distribution and control of diseases (Madigan et al, 2000)
EpilimnionUpper layer of water in a lake (above thermocline). Epilimnion supports algal growth (Henry and Heinke, 1996)
Escherichia Coli O157:H7An emerging enterotoxigenic E.Coli spread by fecal contamination of animal or human origin to food and water (Madigan et al, 2000)
Euphotic ZoneThe surface volume of water in the ocean or deep lake that receives sufficient light to support photosynthesis. Macrophytes grow only when the bottom is within the Euphotic Zone (Henry and Heinke, 1996)
EutrophicThe condition of water being rich in plant nutrients (Cole, 1994). Nutrient-enrichment causes biological productivity to increase, but biodiversity within the aquatic ecosystem to decrease. In turn, eutrophic waters are also anaerobic (deprived of dissolved oxygen). Water is usually considered to be eutrophic if phosphorus loading exceeds 20mg/L.
EutrophicationThe process by which lakes gradually age and become more biologically productive. Eutrophication normally takes thousands of years to progress. However, humans have greatly accelerated this process in thousands of lakes around the globe. More details at http://www.umanitoba.ca/institutes/fisheries/eutro.html (University of Manitoba, 2002)
GreywaterHousehold effluent used for washing and activities other than sewage removal (Scheifer, 2001)
HolomixisIs a phenomenon whereby wind mixes the entire watermass of a lake (Cole, 1994)
HypolimnionLower later of water in a lake or pond (below thermocline), which maintains constant temperature (Henry and Heinke, 1996)
Indicator OrganismsOrganism used to represent all human enteric pathogens, due to its ease of detection, and its ability to conservatively estimate the presence of pathogens. Total coliforms, including E.Coli, are most often used (Henry and Heinke, 1996)
LimnologyThe study of the physical, chemical and biological characteristics of rivers and lakes (i.e. fresh water) (Henry and Heinke, 1996)
Littoral CommunityBound (edge) aquatic systems. Physically transitional (bogs, swamps, marshes) that contain herbivores, omnivores, carnivores and bacterial decomposers (Cole, 1994).
Littoral ZonePeripheral shallows of a lake ecosystem, subject to fluctuating temperatures and erosion. The littoral zone is well-lighted and inhabited by bottom-rooted plants (Cole, 1994).
MacrophytesBottom-rooted aquatic plants (Henry and Heinke, 1996)
MeromicticLakes where only some part of the watermass mixes, and deep water remains stagnant and anaerobic (Cole, 1994)
MesotrophicIs the terminology given to water that is in transition between the stages of oligotrophy and eutrophy. Water is usually considered to be mesotrophic if phosphorus loading is between 10mg/L - 20mg/L.
MetalimnionMiddle layer of water in a lake, containing the thermocline (Henry and Heinke, 1996)
MonomicticHolomictic lakes that experience mixing one during the year (Cole, 1994). Brandy Lake and other shallow lakes in Muskoka are classified as cold monomictic, since thermal stability occurs during the winter, but summertime stratification does not occur.
Nekton CommunityBiological community of larger organisms capable of independent, directed motion (Cole, 1994).
OligotrophicLake that is poor in plant nutrients; generally biologically unproductive (Cole, 1994). Whereas oligotrophic lakes support less biological production, their ecosystems are more biodiverse than nutrient-enriched lakes. Precambrian Shield lakes are usually oligotrophic initially, and naturally progress towards eutrophy over time. This process is often accelerated by anthropogenic effects (see Eutrophication). Water is usually considered to be oligotrophic if its phosphorus loading is less than 10¦Ìg/L.
OmbrotrophicLake that receives all water and mineral inputs from precipitation alone (Cole, 1994).
Pelagic ZoneThe habitat of plankton, where shore and bottom have reduced influence (Cole, 1994)
PeriphytonBenthic algae that grow attached to surfaces such as rocks or larger plants - primary producers and sensitive indicators of environmental change (USEPA, 2002)
PhytoplanktonPlant species of plankton (algae). Predominant species are single-celled green algae. Under proper conditions, blue-green algae can "bloom" (Henry and Heinke, 1996)
PlanktonAny small free-floating organisms living in a body of water (Henry and Heinke, 1996)
Plankton CommunityFound in the pelagic zone. Contains bacteria, protozoans, phytoplankton and zooplankton (Cole, 1994).
Profundal ZoneLakeward of the sublittoral zone, below the thermocline in a stratifed system (Cole, 1994)
Public HealthThe health of the population as a whole (Madigan et al, 2000)
SapropelGlossy black sediments in deep parts of a lake, caused by extended periods of anaerobic conditions (Cole, 1994)
Sublittoral ZoneLakeward from the littoral zone featuring finer-grained sediments. The sublittoral zone is generally well-oxygenated (Cole, 1994).
ThermoclineZone where water temperature changes rapidly with depth. In summer, temperature decreases with depth, in winter it increases with depth as the hypolimnion remains constant in temperature (Henry and Heinke, 1996)
Total ColiformsAll aerobic and facultative anaerobic, gram-negative, non-spore-forming, rod-shaped bacteria that ferment lactose with gas formation within 48 hours at 35 degrees Celcius (APHA et al, 1985, cited in Henry and Heinke, 1996)
Trophogenic ZonePart of a lake's watermass where photosynthesis takes place (Cole, 1994)
Tropholytic ZonePart of a lake's watermass where respiration and decomposition are dominant biological processes (Cole, 1994)
VehicleNonliving source of pathogens that infect large numbers of individuals; common vehicles are food and water (Madigan et al, 2000)
ZooplanktonAnimal species of plankton (crustaceons, rotifers, protozoa etc) (Henry and Heinke, 1996)
|
