Toronto and Region Conservation Authority undertakes special short-term environmental monitoring projects to assess the ecological health of the regional river watersheds and the Toronto waterfront.
Invasive Carp Surveillance
During 2015 routine coastal fisheries surveys, TRCA discovered five Invasive Carp in Toronto Harbour.
Like many invasive species, these adaptive fish can produce many offspring, can outcompete native fishes for food and habitat, and have few native predators to keep their populations in check.
They can also act as carriers for diseases or parasites that could spread to native fishes.
To prevent the establishment of Invasive Carp in Greater Toronto Area waters, TRCA has been actively surveying the Toronto regional waterfront since 2016 in partnership with Fisheries and Oceans Canada.
No additional Invasive Carp have been found since the initial discoveries of 2015.
If you have seen an Invasive Carp or other invasive species, please contact Ontario’s Invading Species Hotline (toll-free) 1-800-563-7711 or report it online at EDD MapS Ontario.
INVASIVE CARP: WHAT YOU NEED TO KNOW!
Sea Lamprey
Since 2005, TRCA has worked in contract partnership with Fisheries and Oceans Canada (DFO) to collect invasive Sea Lamprey during their spawning season (mid-April to mid-June) to reduce their impact on fish communities within Lake Ontario.
There are traps built into the first weirs of the Humber River and Duffins Creek, with the intent of capturing the adult Sea Lamprey as they migrate upstream to spawn.
In 2024, 5,797 invasive Sea Lamprey were caught and removed from three traps in the Humber River and Duffins Creek in partnership with DFO.
The number of Sea Lamprey captured in the Humber trap in 2024 is lower than the previous year.
In 2023, we had a record number of Sea Lamprey visiting the traps, thought to be related to a pause in lampricide treatment during the pandemic. Prior to the 2023 resurgence, Sea Lamprey numbers were declining over the years.
Sea Lamprey are an invasive parasitic fish, native to the Atlantic Ocean, that feed voraciously on the bodily fluids of other fish using their suction cup mouth lined with teeth.
The first reported occurrence of Sea Lamprey in the Great Lakes was in the 1830s; it is believed that they entered the Great Lakes through the shipping channels.
In the 1940s and 1950s, Sea Lamprey played a significant role in the collapse of the lake trout and whitefish fisheries, which have both been historic economic mainstays of the Great Lakes fishery.
TRCA continues to work with outside agencies that have a collaborative interest in fish community health for the benefit of not only TRCA’s jurisdiction but the Great Lakes Region overall.
Acoustic Telemetry
2024 marks the fourteenth year the Acoustic Telemetry research study has been underway.
Thanks to this high-tech fish tagging study, resource managers are learning how fish use restored habitats in order to enhance or expand restoration efforts throughout the Toronto Harbour.
In partnership with researchers from Carleton University and the Department of Fisheries and Oceans Canada, TRCA environmental monitoring crews have tagged 579 native and non-native fish with acoustic transmitters since 2010, in an effort to track their feeding and spawning activities 24 hours a day year-round.
Understanding the mysteries of fish behaviour, including where and how long fish are spawning and feeding throughout the seasons, will help TRCA continue to manage aquatic habitat along Toronto’s waterfront.
The goal is to support a community of desirable native fish species as well as a self-sustaining fishery.
Future plans for this project include expanding the study area to pick up acoustic signals from tagged fish travelling along the north shore of Lake Ontario. This information will help to answer questions about how fish move regionally and how agencies can work together to improve the health of Lake Ontario.
Seaton Development Lands
The Central Pickering Development Plan outlines the blueprint for a new urban community of up to 70,000 people and 35,000 jobs, along with a designated agricultural preserve on the west side of Duffins Creek.
The Seaton project is unique because 53% or 1,520 ha of the planning area is designated as a Natural Heritage System (NHS) and will be retained in public ownership.
Due to the size and scale of this development, its sustainability aspects, and the sensitivity of the nearby ecosystems, TRCA initiated a large-scale monitoring program in 2014 to evaluate the natural heritage of the Seaton development lands.
TRCA will be monitoring both the aquatic and terrestrial ecosystem (pre, during, and post development) to determine if the sustainability practices and the large natural heritage system are sufficient to protect the ecological integrity of the sensitive natural heritage features within the project boundaries.
For example, the Seaton development lands are home to important local populations of the provincially endangered Redside Dace as well as the sensitive Brook Trout, which is the only remaining native Salmonid fish species naturally occurring in headwater sections of the Humber, Rouge, and Duffins watersheds.
Currently there are long-term monitoring plots set-up to track changes in vegetation and bird communities, as well as aquatic sites to monitor fish and benthic macroinvertebrate communities.
Conductivity loggers, used to estimate chloride concentrations, as well as year-round temperature and water quality monitoring stations are also in place.
Results from this monitoring program are expected to largely influence future planning decisions regarding the Seaton development lands and potentially future development activities in other TRCA watersheds.
Nearshore Community Index Netting
Funded by the Canada-Ontario Agreement (COA), TRCA, under contract by the Ontario Ministry of Natural Resources, is involved in nearshore fish community identification and assessments at 24 sites along the Toronto regional waterfront.
Nearshore Community Index Netting (NSCIN) is an overnight netting program designed to evaluate abundance and other attributes (such as length, weight, and age) of fish species that inhabit the littoral (i.e. close to shore) zone of Ontario lakes.
The project follows the Ministry’s NSCIN guidelines. To date, NSCIN trap netting has been conducted along the Toronto regional waterfront in 2006, 2007, 2010, 2012, 2016, 2018, 2022, and 2024.
These nearshore fisheries surveys add to the knowledge gained through TRCA’s annual coastal fisheries surveys, which have been ongoing since the 1960s in support of the Toronto and Regions Remedial Action Plan (RAP).