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Aquatic Habitat Toronto

West Nile Virus Monitoring

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Benthic Invertebrate Summary: 2001-08

Fish Community Summary: 2001-09

Fish Communities of the Toronto Waterfront: Summary and Assessment 1989-2005

Diagnosis: Stream Sickness Article!

Are Toronto's Streams sick? A look at the fish and benthic invertebrate communities in the Toronto region in relation to the urban stream syndrome. Abstract Only! 

Tracking Fish in Toronto Harbour, Ontario Nature Summer 2015  

2013 Watershed Report Cards

Resource Library

Photo & Video Gallery

Environmental Monitoring News

 

Training & Workshops


Benthic Invertebrate ID June 4, 5 & 7, 2016!

Class 2 Backpack Electrofishing Certification May 27, 2016. Course is now full.

Ontario Fish ID June 4 & 5, 2016!

Ontario Stream Assessment Protocol (OSAP) June 6 to 10, 2016!

Contact


Angela Wallace, MSc.

Project Manager, Aquatic Monitoring & Analysis

Environmental Monitoring & Data Management

awallace@trca.on.ca

Aquatic Habitat and Species Monitoring

Aquatic4 Collecting BMI Samples (SC Biocriteria) - Cropped Field Crew Electrofishing1 - Cropped Fluvial G 4 RC From 2012 RWMP Progress Report - Cropped

What Do We Monitor and Why?

TRCA monitors the following key indicators to assess the health of our local streams, rivers and Lake Ontario waterfront:

  • Benthic Macroinvertebrates
  • Fish Communities and Habitat
  • Fluvial Geomorphology
  • Water Temperature

Data on benthics are collected annually from May to November at 150 monitoring stations, while the other stream health indicators listed above are sampled on a three-year rotation.  Sampling follows the methodologies outlined in the Ontario Stream Assessment Protocol (OSAP)

Fish surveys have also been conducted within Toronto Harbour since 1989 in order to track the effectiveness of Remedial Action Plan (RAP) remedial measures for the Toronto & Region Area of Concern (AOC). AOCs are formally recognized by the governments of Canada and the United States in the Great Lakes Water Quality Agreement (GLWQA) amendments of 1987.  Fish surveys are also conducted within Toronto Harbour as part of short-term special projects.

TRCA is also a member of Aquatic Habitat Toronto (AHT), a group of agencies that have a vested interest in the improvement of aquatic habitat on the Toronto Waterfront.  AHT is focused on completing the goals of the Toronto Waterfront Aquatic Habitat Restoration Strategy and the Urban Recreational Fisheries Strategy, as well as working with academia on a multi-year fish-tagging study.

Mosquito larvae populations are surveyed through the WNV Surveillance and Monitoring Program. The data collected is used to identify sites of potential concern or vector mosquito "hot spots" and then follow up with appropriate management actions.

By knowing the health of our stream, river and waterfront habitats, TRCA can help protect, improve and restore our watersheds for future generations.

Benthic Macroinvertebrates:Benthic macroinvertebrates ('aquatic bugs') are organisms that live within the bottom of streams and rivers for part of their life.   They can include worms, snails, mussels, leeches, crayfish as well as the immature life stages of insects.

Benthics are useful as water quality 'indicators' in stream ecosystems because they:

  • live in water for all or most of their life,
  • are sedentary and easy to collect,
  • often live between one to three years,
  • are sensitive to disturbances in the environment,
  • are easy to identify in a laboratory, and
  • occur in high diversity, so many different species can be studied for tolerance to amount and types of pollution.

Monitoring biological species can be more effective in explaining changes in stream health over time versus traditional chemical evaluations.  

Water Beetle

Photo: Water Beetle

Fish Community and Habitat:Fish communities are a combination of different fish species living and interacting with each other at a specific location and / or time. 

Fish are excellent indicators of stream health because they:

  • are easy to collect with the right equipment,
  • are easy to identify in the field,
  • live for several years, and only in the water,
  • are sensitive to changes in their environment,
  • differ in their tolerance to amount and types of pollution, and
  • are sensitive to forms of pollution that chemical tests may miss.

Aquatic habitat surveys, both in-stream and bank assessments, were completed together with fish community surveys.  In-stream habitat characteristics such as dominant vegetation, stream widths and water depth can help predict what types of aquatic species are likely to be found.  Bank assessment quantifies the condition and stability of land bordering the stream.

Fish ID Table

Photo: Fish ID Table.

Water Temperature:A thermally stable stream is one that has a temperature that does not experience any large fluctuations throughout the warmer season i.e. late summer.  Wide fluctuations in temperature suggest warm-water habitats that are not moderated by the constant, cool influence of groundwater. At stable sites, water temperature is controlled more by groundwater than by air temperature or the heat from the sun. 

Temperature is a major factor that determines which aquatic species, fish or benthics, live in a particular stream. For example, a thermally stable stream is an important factor for the survival and reproduction of cool and cold-water species such as Brook Trout.  Toronto watersheds are historically dominated by coldwater stream conditions.  The more urbanized the surrounding landscape becomes, the higher the water temperatures.

Brook Trout

Photo: Brook Trout.

Fish Communities and Habitat:Fish communities are a combination of different fish species living and interacting with each other at a specific location and / or time. 

Fish are excellent indicators of stream health because they:

  • are easy to collect with the right equipment,
  • are easy to identify in the field,
  • live for several years, and only in the water,
  • are sensitive to changes in their environment,
  • differ in their tolerance to amount and types of pollution, and
  • are sensitive to forms of pollution that chemical tests may miss.

Aquatic habitat surveys, both in-stream and bank assessments, were completed together with fish community surveys.  In-stream habitat characteristics such as dominant vegetation, stream widths and water depth can help predict what types of aquatic species are likely to be found.  Bank assessment quantifies the condition and stability of land bordering the stream.

Fish ID Table

Photo: Fish ID Table.

Fluvial Geomorphology:Fluvial geomorphology measures the physical characteristics of the stream channels such as physical dimensions, bed and bank properties.  

It also strives to understand how the natural setting and human land use in a watershed determine its shape and attempts to predict the physical changes that may occur in response to alterations in watershed conditions.  For example, man-made channel modifications in urban areas may occur in less than a decade, while natural adjustments of watercourses may take thousands of years.

Understanding these physical processes, both natural and man-made, helps to identify areas in a river system that may be prone to erosion, flooding or other problems.  This data is key to helping guide conservation and restoration planning and development activities.

Note: The 150 fluvial geomorphology sites differ slightly from the sites that are monitored for aquatic fish habitat and communities and benthic macroinvertebrates.

Fluvial Geomorphology

Photo: Surveying long profiles at a restored site that incorporated natural channel design. The survey information will graph how the gradient of the stream changes along its length.

Vector:An insect, animal, etc., that carries germs that cause disease. Not all mosquitos carry West Nile Virus.

Groundwater:Water that occurs below the surface of the Earth, where it occupies spaces in soils or geologic strata.

Most groundwater comes from precipitation, which gradually percolates into the Earth. Typically, 10-20% of precipitation eventually enters aquifers. Most groundwater is free of pathogenic organisms, and purification for domestic or industrial use is not necessary. Furthermore, groundwater supplies are not seriously affected by short droughts and are available in many areas that do not have dependable surface water supplies.

What Are The Data Telling Us?

Aquatic habitat and species data analyses over the last 13 years shows that urban development, including higher road densities, in-stream habitat modifications, and decreases in forest cover, are largely responsible for the overall decline of stream health in our regions. This suggests that decreases in urban area and road density as well as increases in natural cover (e.g. % forest) will maintain or improve the health of our watersheds in the future.

Using recent data analyses, specifically the Index of Biotic Integrity and Hilsenhoff's Family Biotic Index, the map below shows the average health of aquatic habitats and communities across TRCA watersheds.   

Individal monitoring sites in good health are usually located in the Duffins Creek, Rouge River and Humber River watersheds.  Generally, healthier sites are located in coldwater streams in the upper reaches of the watersheds and have low levels of urbanization (<10%) and relatively high levels of forest (12-40%). 

Unhealthy sites are located in streams surrounded by high levels of urbanization (63-100%) and low levels of forest cover (<2%).  These sites also tend to have man-made modifications such as concrete lined channels.  Most of the impaired sites are located in the Mimico Creek, Don River and Highland Creek watersheds.

TRCA Watershed Grades Map - Stream Health

Family Biotic Index (FBI):

Hilsenhoff's Family Biotic Index (FBI) showing the FBI tolerance to organic pollution values, which range from 1 to 10 and increases as water quality decreases.

Biotic Index Water Quality Degree of Organic Pollution

0.00 - 3.75

Excellent

Organic pollution unlikely

3.76 - 4.25

Very Good

Possible slight organic pollution

4.26 - 5.00

Good

Some organic pollution probable

5.01 - 5.75

Fair

Fairly substantial pollution likely

5.76 - 6.50

Fairly Poor

Substantial pollution likely

6.51 - 7.25

Poor

Very substantial pollution likely

7.26 - 10.00

Very Poor

Severe organic pollution likely

 

Index of Biotic Integrity (IBI):

An Index of Biotic Integrity (IBI) score is a measure of stream health that uses nine measures of fish community composition to rate overall water quality on a scale of 9 (poor) to 45 (very good).

IBI Score Water Quality
38-45

Very Good

28-37

Good

21-27

Fair

9-20

Very Poor