Urban Streams
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  • ecology
    The science that deals with the interrelationships between organisms and their environment.

  • ecosystem
    (1) The inter-dependent organisms and physical environment in a given area.
    (2) The sum total of vegetation, animals, organisms, and the physical environment in which they inter-react.
    (3) An ecological unit consisting of biotic communities and the non-living (abiotic) environment which interreact to form a stable system. The largest functional unit in ecology. e.g. pond, forest.

  • erosion
    The wearing down of a surface caused by external factors. Soil erosion may be caused by wind, water or human activity.

  • ESA
    (1) "Environmentally Sensitive Area". Areas which require special management to protect fish and wildlife resources and natural systems or processes, including those which are rare, outstanding or endangered.
    (2) "Endangered Species Act" - (US).

  • estivation
    A kind of summertime hibernation.

  • estuary
    A partially enclosed body of water freely connected to the ocean and within which the seawater of the lower estuary is measurably diluted by mixing with freshwater and in the upper estuary where tidal fluctuations affect river water levels. Within the estuary, species such as salmon can find food, shelter and a seawater/freshwater acclimation holding area.


  • felts
    Non-slip soles on the boots of waders.

  • fish
    (1) Any vertebrate animal provided with gills throughout life and cold-blooded, the limbs being modified into fins.
    (2) Fish are defined as: shellfish, crustaceans, marine animals, the eggs, spawn, spat and juvenile stages of fish, shellfish, crustaceans, and marine animals. (Canada Fisheries Act, sec.31.5)

  • fish habitat
    Spawning grounds and nursery, rearing, food supply and migration areas on which fish depend directly or indirectly in order to carry out their life processes. (Canada Fisheries Act, sec.31.5)

  • fishery operating window
    The time period of reduced risk for commercial, sport and resident fish species, based on their life cycle. The fishery operating window is the time of year in which there are no fish eggs or alevins present in the substrates of local streams or rivers. This is the preferred time for any instream work or development which could have an impact on fish or stream habitat. Prior to work commencing, proponents should contact DFO and MELP for information regarding species timing windows for work in a specific area.

  • freshet
    A sudden rise in water level associated with rainfall or snow melt.

  • fry
    Juvenile salmonids that have matured past the alevin stage such that they have absorbed the yolk sac and emerged from the gravel.