Track the Progress

The HHRAP partners are working diligently to restore beneficial uses in the Area of Concern (AOC). It has taken large financial investments and the hard work of many partners to begin to reverse the effects of 150 years of pollution. HHRAP partners and technical experts work together to identify the actions needed to meet restoration goals for the AOC and track outcomes relevant to each Beneficial Use Impairment (BUI).  

For more information, read our BUI factsheets.


Click on the links below to jump down to the section:

BUI 1a Restrictions on Fish Consumption

Status: Impaired

Delisting Criteria: Consumption advisories for fish of interest in Hamilton Harbour are non-restrictive or no more restrictive than the advisories for suitable reference site(s) due to contaminants from locally controllable sources.  

Details: A goal of the HHRAP is to make fish safer to eat for the community. Most fish from Hamilton Harbour are safe to eat; however, restrictions on their consumption are advised.   

In the Hamilton Harbour AOC, consumption advisories (or the number of fish meals that can be eaten in a given time period) are driven by a contaminant called PCBs (polychlorinated biphenyls). The harbour is contaminated with PCBs due to past manufacturing and waste management practices. Contaminant levels in fish are measured every few years by the Ontario Ministry of the Environment, Conservation and Parks and the results are used to issue consumption advice through annual updates to the Guide to Eating Ontario Fish.

Fish consumption restrictions should lessen as historical pollution is cleaned up and the harbour becomes a healthier place for fish to live. Windermere Basin is a PCB-contaminated site within the Hamilton Harbour AOC that was remediated by dredging the contaminated sediment and capping the basin. It was later made into a wetland. Plans to remediate PCB-contaminated sediment at the Kenilworth and Strathearne Boat Slips are being developed.

BUI 1b Restrictions on Wildlife Consumption

Status: Requires Further Assessment

Delisting Criteria: There are no restrictions on consumption of wildlife from the harbour attributable to local sources.

Details: PCBs (Polychlorinated biphenyls) are harmful substances that can accumulate in wildlife, and high concentrations of PCBs in wildlife make them unsafe for people to eat. While PCBs are a contaminant of concern in the Hamilton Harbour AOC, several factors make it unlikely that humans are being exposed to PCBs through consumption of local wildlife.   

Hunting and consuming local wildlife in the Hamilton Harbour AOC is generally not permitted. Wildlife species are protected by the Migratory Birds Convention Act and the Ontario Fish and Wildlife Conservation Act, and local laws prohibit the use of firearms in the area.   

There is concern, however, for those who have Indigenous treaty rights to harvest wildlife from the Hamilton Harbour AOC. Further engagement with Indigenous communities is needed to better understand potential risks.   

Projects that reduce or limit PCB exposure in Hamilton Harbour (as listed under BUI 1a Restrictions on Fish Consumption above) will lessen contamination in wildlife over time.   

For more information, read our BUI factsheets. 

BUI 2 Tainting of Fish and Wildlife

Status: Not Impaired

Details: Survey results confirmed no tainting of fish or wildlife flavour in Hamilton Harbour.

A 1995-1997 survey funded by Health Canada asked people fishing in the area about flavour issues; only 2 out of the 375 people surveyed reported fish that tasted or smelled bad. 

Also, unpleasant fish and wildlife flavours are usually caused by a chemical compound called phenols, which is not a contaminant of concern in Hamilton Harbour. 

Read the survey.

BUI 3a Degradation of Fish Populations

Status: Impaired

Delisting Criteria: The nearshore fish community has the following structure:

A. Shift from a fish community indicative of eutrophic environments (e.g., White Perch, Alewife, bullheads and carp) to a self-sustaining community more representative of a mesotrophic environment with a balanced trophic composition that includes top predators (e.g., Northern Pike, Largemouth Bass and Walleye) and other native species (e.g., Suckers, Yellow Perch and sunfishes). 

B. Attain an Index of Biotic Integrity (IBI) of 55-60 for Hamilton Harbour and maintain the target score for two sequences of monitoring carried out a minimum of every three years. The IBI incorporates components of native species richness, numbers and biomass; piscivore biomass; non-native species; and reflects water quality and the quality of fish habitat. 

Details: Hamilton Harbour supports over 40 fish species, but the fish community is dominated by non-native species like common carp and more recently, goldfish and rudd as well as pollution tolerant species like brown bullhead.   

The current fish community is characteristic of a eutrophic lake environment, which tends to have low water clarity, algal issues, low dissolved oxygen levels, and mostly warm-water fish species. Improvements to the fishery will require a shift toward a mesotrophic lake environment, which typically has higher water clarity and supports more cold-water and predatory fish.   

Scientists use a calculation called an Index of Biotic Integrity, or IBI, to measure fish community health. Higher values indicate a diverse fish community with few non-native fishes, good water quality, good physical habitat supply, and top predator abundance. Improvements in Hamilton Harbour’s IBI scores were seen in the mid-1990s to mid-2000s, but the scores have recently declined.   

The Ontario Ministry of Natural Resources and Forestry has stocked walleye, a top predator, in Hamilton Harbour since 2012. Stocked walleye are the most abundant top predator in recent trap net catches.   

The Royal Botanical Garden’s Fishway at the entrance to Cootes Paradise Marsh has excluded large common carp from the marsh since 1996, allowing for regrowth of aquatic vegetation and habitat for other fishes. Carp have declined significantly since this addition. Despite these improvements, new non-native species like goldfish and rudd have invaded the harbour and Cootes Paradise.   

A fish population status assessment is underway to review the current state of Hamilton Harbour’s fish community and identify actions that can be taken to remediate this issue.    

For more information, read our BUI factsheets. 

BUI 3b Degradation of Wildlife Populations

Status: Impaired

Delisting Criteria (proposed): The overall objective is to have a sustainable mixed community of colonial waterbirds. In general, the criteria is aiming for an increase of the rarer species and a reduction in the number of over-abundant species. Management of colonial waterbirds and achieving specific populations of species requires an adaptive management approach to ensure sustainable populations continue to the extent possible after delisting.   

Details: In the mid-1980s when the HHRAP was developed, the waterbird community of Hamilton Harbour was dominated by only a few abundant species. The goal of the HHRAP was for Hamilton Harbour to have a sustainable, mixed community of colonial waterbirds.   

Colonial waterbirds are birds that nest in groups and generally return to the same nesting spot every year. In Hamilton Harbour, colonial waterbirds include black-crowned night-herons, Caspian terns, common terns, double-crested cormorants, herring gulls, and ring-billed gulls.   

To achieve this goal, it was essential to provide clean and permanent nesting habitat. Eight islands of nesting habitat were constructed along the northeastern shore of the Hamilton Harbour and in Windermere Basin. Active management of colonial waterbird populations was implemented to ensure that species more impacted by human presence had reserved nesting space, and to prevent overabundant colonies of double-crested cormorants and ring-billed gulls from occupying all available nesting habitat.  

Over the years, considerable progress has been made in the conservation efforts for the colonial waterbird populations and a draft redesignation report proposing status change from impaired to not impaired was released in 2022. Public engagement on the draft report has been completed and engagement with local Indigenous communities is ongoing.  

To learn more, read the draft redesignation report or view our story map.

BUI 4 Fish Tumours or Other Deformities

Status: Requires Further Assessment

Delisting Criteria: Incidence rates of fish tumours in brown bullheads, as an indicator species, do not statistically exceed rates at relevant reference site(s).

Details: Contaminants such as PAHs (polycyclic aromatic hydrocarbons) have been linked to increased liver tumour incidence in fish. Researchers study liver tumours in brown bullheads, a type of catfish, as an indication of local contamination. External tumours are no longer used to assess contamination as they can be the result of viruses or other pathogens and have not been linked directly to contamination in the Great Lakes.   

In the past, the Hamilton Harbour AOC had a higher incidence of brown bullhead liver tumours when compared to one reference site (nearby Jordan Harbour). However, this may be explained by the sampling of older fish, as tumour rates often increase with age. When a wider age range of fish was sampled in 2012, no liver tumours were found in brown bullheads from Hamilton Harbour.      

Further analysis of brown bullhead livers will be undertaken following the clean-up of Randle Reef, the largest known source of PAHs in the AOC, and an updated BUI status report will be produced.    

For more information, read our BUI factsheets. 

BUI 5 Bird or Animal Deformities or Reproductive Problems

Status: Requires Further Assessment

Delisting Criteria: The types and frequency of deformities and/or reproductive impairments associated with contaminant exposure are similar to those seen at a suitable reference site(s), and do not result in a population level effect as examined through sentinel species (e.g., snapping turtles and herring gulls). 

Details: Problems associated with reproduction, development, and deformities in aquatic birds and other wildlife can be caused by elevated exposure to contaminants. In the 1970s, colonial waterbirds nesting in the Hamilton Harbour AOC had low hatching success in addition to gross deformities, like crossed beaks. At the same time, very high levels of pollutants were also reported in bird eggs. Elevated rates of unhatched eggs and hatchling deformities were also found in snapping turtles from Cootes Paradise in the 1980s.    

Herring gulls and double-crested cormorants (representing colonial waterbirds), and snapping turtles were selected for assessing wildlife deformities and reproductive problems in the Hamilton Harbour AOC.    

Two large multi-year studies that concluded in 2016 showed no evidence of contaminant-induced impairment of reproduction or development in colonial waterbirds and snapping turtles in the Hamilton Harbour AOC. Supplemental information from a third study looking at the northern leopard frog also indicated no evidence of contaminant-induced impairment from historical human activities.    

For more information, see the status assessments of colonial waterbirds and snapping turtles

BUI 6 Degradation of Benthos

Status: Impaired

Delisting Criteria: Remedial actions to address contaminated sediment have been implemented and follow-up monitoring demonstrates improved benthic community structure and a reduction in acute and chronic toxicity attributable to contaminants in Hamilton Harbour sediments relative to historical surveys. 

Progress should continue to be made towards these desired outcomes: 

  1. Littoral Zone (depth < upper limit of maximum extent of anoxic conditions)
    • Benthic community structure (BCS) is not different from that of appropriate reference conditions and BCS is not correlated to sediment contaminant levels among sites
    • Acute and chronic sediment toxicity attributable to contaminants in sediments are not different from appropriate reference conditions
  2. Profundal Zone (depth > upper limit of maximum extent of anoxic conditions)
    • BCS is not correlated to sediment contaminant levels among sites
    • Acute and chronic sediment toxicity 

Details: Benthos are animals that live in the bottom sediment of waterbodies and are an important food source for some fishes. Examples of benthos include worms, snails, and dragonfly larvae.    

Exposure to toxic chemicals in the sediment and low oxygen caused the benthic community in Hamilton Harbour to become dominated by pollution-tolerant worms. The primary goal now is to improve benthic community numbers and diversity by remediating contaminated areas.    

Hamilton Harbour contains the most contaminated sediment in the Canadian Areas of Concern. A step toward restoring the benthic community is the clean-up of Randle Reef, which dredged the most heavily contaminated sediment and isolated it within an Engineered Containment Facility. Benthic surveys will be used to provide an indicator of success following project completion. It is anticipated that several years will be required after the completion of the project to allow the local benthic community to recolonize the site.   

For more information, read our BUI factsheets. 

Learn more about Randle Reef.

BUI 7 Restrictions on Dredging Activities

Status: Impaired

Delisting Criteria:  When contaminants in sediments do not exceed biological and chemical standards, criteria, or guidelines such that there are no restrictions on disposal activities (i.e., dredge material does not require disposal at a hazardous waste facility) associated with navigational dredging. 

Details: Hamilton Harbour is an active port. It accepts around 600 international and domestic ships every year. For safe passage of ships, navigational dredging, a process where sediment is removed from the bottom of a water body for any purpose associated with navigation and shipping, periodically occurs in Hamilton Harbour’s channels and slips.   

When sediment is removed for navigational dredging, the material is tested for contaminants. If contaminant concentrations are high enough to be considered hazardous waste, sediment disposal must occur at a specially licensed hazardous waste facility in Ontario or Québec. This would be considered a restriction on navigational dredging activities due the additional costs associated with disposal.  

In the last decade, certain areas used for navigational purposes have been identified as potentially having hazardous levels of contaminants. Determining whether contamination exists in areas of navigational dredging will be the basis of a future assessment.  

For more information, see the 2022 criteria update.

BUI 8 Eutrophication or Undesirable Algae

Status: Impaired

View Chart

Delisting Criteria:  There are no persistent adverse water quality conditions attributable to cultural eutrophication for a period of three consecutive years. Listed are the anticipated environmental conditions for Hamilton Harbour (Table A), Cootes Paradise and Grindstone Creek Area (Table B) and the annual net loading targets required by major harbour point sources to achieve those conditions (Table C). Click View Chart to see tables. 

Details: Eutrophication occurs when excessive amounts of nutrients from human activity enter a water body resulting in excessive algal growth or harmful algal blooms (HABs). The key nutrient driving algal growth and HABs is phosphorus. Some sources of phosphorus include agriculture, industry, roads and homes, as well as treated and untreated sewage.   

Algal blooms can block sunlight from reaching plants that grow below the surface of Hamilton Harbour. When the algae and plants eventually die, the degradation process consumes oxygen and in doing so can deplete the oxygen in the bottom waters. Significant losses of oxygen have the potential to negatively impact fish habitat and populations, zooplankton and phytoplankton (fish food living in the water), benthos (fish food living in the bottom sediment), beaches, and aesthetics. As a result, eutrophication has ties to several of the Hamilton Harbour AOC BUIs.   

Phosphorus loads to the harbour can be significantly lowered through wastewater treatment plant upgrades and optimizations.  For example, phosphorus loads are expected by lowered by more than half with the completion of the Woodward Wastewater Treatment Plant (2023) and the Skyway Wastewater Treatment Plant (2016). With these point-source improvements, watershed inputs will become the dominant source of nutrients to the harbour.    

Reducing nutrients loads into the Hamilton Harbour AOC involves many partners. The City of Hamilton has an ongoing cross-connection program that detects and corrects sewage accidentally entering the harbour from domestic sewage and industrial wastewater. Stewardship programs run by Conservation Halton, Hamilton Conservation Authority and Green Venture help to restore the natural water cycle by slowing water flows and enabling infiltration to ground, thus preventing erosion and the flushing of sediment and nutrients into the waterways. Conservation Halton, the Hamilton Conservation Authority and the City of Hamilton also have water quality monitoring programs which help to detect problem areas and focus remedial actions. These are important steps to improving the quality of water entering Hamilton Harbour and Cootes Paradise, especially from the Chedoke Creek watershed where phosphorus inputs have been high.   

While inputs of phosphorus to Hamilton Harbour have lessened over time, there can be historical accumulations of phosphorus in the sediment, referred to as legacy phosphorus. Under low-oxygen conditions, sediment-bound phosphorus is released back to the water column through a process referred to as internal phosphorus loading. Time is needed to naturally flush out this historical buildup of phosphorus from the AOC.   

 For more information, see our BUI factsheets and loadings report that tracks the reduction in nutrients entering the harbour. 

BUI 9 Drinking Water

Status: Not Impaired

Details: BUI 9 has never been impaired and is not applicable for Hamilton Harbour, as it has no drinking water intakes. Hamilton and Halton residents get their municipal tap water from Lake Ontario. 

BUI 10 Beach Closings

Status: Impaired

Delisting Criteria:   

  1. For a minimum of three consecutive years, Hamilton Harbour public bathing beaches be open 80% or more of the swimming season as determined by the City of Hamilton Public Health Unit. 
  2. Where attainment of over 80% of the swimming season cannot be achieved the following conditions must be met: a. Sources of fecal pollution are identified and remedial actions and management plans are implemented; and b. The causes for beach postings (e.g., cyanobacteria) are known and appropriate risk management strategies and communication plans are in place to protect human health. 

Details: Hamilton Harbour was home to two man-made public bathing beaches at Pier 4 Park and Bayfront Park. Before they opened, swimming was prohibited in Hamilton Harbour by a 1930 Hamilton Harbour Commissioners by-law due to health concerns about E. coli, a bacteria transmitted from people and wildlife to the waterways via sewage and feces. Toxins from cyanobacteria also impact Hamilton Harbour’s beach. Toxic algal blooms, generated offshore, can circulate toward and accumulate at the beach. Bayfront Park was permanently closed in 2017 due to poor water quality due to historically high E. coli concentrations and persistent cyanobacteria blooms.   

Water quality is currently tested at Pier 4 Park beach by Hamilton Public Health four times a week during the swimming season from the Victoria Day long weekend to the end of August for both E. coli and toxins from cyanobacteria. Public Health alerts the public through their website when it is not advisable to swim and by posting signs at the beach.  

Research has shown that at Hamilton Harbour beaches, the source of E. coli is gull and waterfowl fecal matter, not humans. Initiatives by the City of Hamilton to deter birds at the parks have made vast improvements in reducing bird E. coli levels at the beach.  These include: installing signs advising the public not to feed waterfowl, beach grooming, walkway sweeping, scaring the birds away, and fencing.    

Through time, upgrades to wastewater treatment and other actions to address the Eutrophication or Undesirable Algae BUI will reduce the supply of nutrients and potentially reduce the occurrence of the cyanobacteria blooms.      

For more information on this topic see the 2020 criteria update.

BUI 11 Degradation of Aesthetics

Status: Impaired

Delisting Criteria: The waters are free of any substance due to human activity which produces a persistent objectionable deposit, unnatural colour or turbidity, unnatural odour (e.g., oil slick, surface scum, algae) for a period of three consecutive years. 

Details: The aesthetics of an area can influence the public perception of the health of the water. Improvements in Hamilton Harbour’s aesthetics are an important marker of progress in its remediation.   

The Hamilton Harbour AOC’s aesthetics was deemed impaired in 1992 due to occasional oil sheens, algal blooms, objectionable turbidity (murky water), floating scum, debris, putrid material, and a lack of public access to the waterfront. While the harbour doesn’t have the same severe persistent aesthetic issues such as oil slicks as in the past, incidents affecting its appearance and smell still occur.    

Spill regulations and industrial pollution prevention plans (e.g., the Municipal-Industrial Strategy for Abatement) helped to dramatically improve the quality of industrial discharges to Hamilton Harbour. Special outreach initiatives like the City of Hamilton’s “Own Your Throne” campaign is also educating the public on the proper disposal of non-flushable items (e.g., tampon applicators, needles, wipes) that can otherwise end up in Hamilton Harbour from the combined sewer system overflows. 

An aesthetics monitoring program was undertaken from 2012-2018 to assess four aesthetics indicators: clarity, colour, odour, and debris.  These indicators form the basis of the “Aesthetics Quality Index”, an established approach used to assess the status of the aesthetics BUI at other AOCs. Monitoring locations included the centre of the harbour and the Fishway, and in 2018 was expanded to include the northeastern shoreline, La Salle Park, Pier 8, and the Waterfront Trail.  

For more information on Hamilton Harbour’s aesthetics, see the 2019 status assessment

BUI 12 Added Costs to Agriculture or Industry

Status: Not Impaired

Details: There are no significant additional costs beyond those normally required to treat water prior to industrial uses in Hamilton Harbour and water from the harbour is not used in agriculture. 

BUI 13 Degradation of Phytoplankton & Zooplankton Populations

Status: Requires Further Assessment

IJC Delisting Guidance: When phytoplankton and zooplankton community structure does not significantly diverge from unimpacted control sites of comparable physical and chemical characteristics. 

Further in the absence of community structure data, this use will be considered restored when phytoplankton and zooplankton bioassays confirm no significant toxicity in ambient waters. 

Details: Phytoplankton and zooplankton populations are key components of the aquatic food web. Phytoplankton are photosynthetic aquatic plant-like organisms that live in the water column which use nutrients (e.g., phosphorus) and sunlight to grow. Zooplankton are microscopic animals that eat algae and microbes. In turn, fish and larger predators feed on zooplankton.   

Hamilton Harbour has fewer preferred phytoplankton species than expected given the excessive nutrient levels in the water, and considerably more zooplankton. The interaction of food web communities in the AOC continues to be studied by scientists.  

Action is being taken to reduce excess phosphorus and other nutrients from entering Hamilton Harbour to address the Eutrophication or Undesirable Algae BUI. Top predators like walleye are also being reintroduced to address the Degradation of Fish Populations BUI. Management actions for these two BUIs are expected to result in improvements to phytoplankton and zooplankton communities.  

For more information, see the BUI factsheets.

BUI 14 Loss of Fish and Wildlife Habitat

Status: Impaired

Delisting Criteria:

1. Emergent and submergent aquatic plants measure ≥ 500 hectares (230 ha in Hamilton Harbour + Windermere Basin and 270 ha in Cootes Paradise + Grindstone Creek Marshes*). 

2. Improved littoral shore (0-5 m depth) measures ≥ 15 kilometres.

3. Wildlife habitat measures ≥ 300 hectares.

4. Colonial nesting waterbird island habitat measures ≥ 1.5 hectares.

5. The quality and quantity of fish and wildlife habitat in Hamilton Harbour (including Windermere Basin, Cootes Paradise, and Grindstone Creek Marshes) improves to support the fish and wildlife populations identified in Beneficial Use iii. 

* Breakdown: Cootes Paradise = 230 ha, and Grindstone Creek = 40 ha 

Details: Habitat includes the physical, chemical, and biological environment in which an animal lives. For fish, this includes dissolved oxygen, water temperature, aquatic plants, food, and substrate (e.g., rocks). For colonial waterbirds that return every spring to nest in Hamilton Harbour, this includes enough space to nest.   

Historically, over 70% of wetland habitat in Hamilton Harbour has been lost due to infilling for industry and the port, as well as from navigational dredging. Cootes Paradise Marsh, Grindstone Creek Marsh, and the shore of Hamilton Harbour were severely degraded. Hamilton Harbour lost most of its underwater reefs and shoals used by fish for spawning and nursery habitat. Colonial waterbirds resided on port lands that were contaminated or slated for development.   

A number of activities have been undertaken to restore habitat in Hamilton Harbour. Eight islands for colonial waterbird nesting were constructed north of the Canada Centre for Inland Waters and in Windermere Basin. Fish habitat has been created to support spawning for walleye, pike, and bass in numerous areas, the latest installation being in the west of Hamilton Harbour, under the new boardwalk at Piers 5-8 created by the Hamilton Waterfront Trust.   

More aquatic vegetation is needed in Grindstone and Cootes Paradise Marshes. Community volunteers help with annual marsh planting events in Cootes Paradise and Grindstone Creek Marshes hosted by the Bay Area Restoration Council and the Royal Botanical Gardens.  

Projects to control invasive species and improve water quality will in turn help these new plants to grow and thrive. A status assessment of fish and wildlife habitat is underway.   

 For more information, please see our BUI factsheets