Fish is a nutritious food that can be a valuable part of a healthy, balanced diet. It’s packed with high-quality protein, beneficial Omega-3 fatty acids, and various essential nutrients.
However, fish can sometimes contain contaminants from natural sources or human activities. The suitability of different fish types and sizes for consumption can vary depending on where they are caught.
This fish guide provides straightforward information to help everyone, including sensitive populations like children under 15 and pregnant individuals, make informed choices about eating fish caught from Ontario lakes and rivers. Our aim is to help you enjoy the benefits of fish while minimizing exposure to toxins.
We analyze fish for contaminant levels through the Fish Contaminant Monitoring Program. Based on these measurements and guidelines from Health Canada, we determine safe monthly consumption limits for various fish types, sizes, and locations in Ontario. These recommendations are known as “consumption advice” or advisories.
Explore our interactive map featuring over 2,700 fishing spots across Ontario. Simply click on a location to view the specific fish consumption advisories for that area.
It’s important to note that for some locations, our consumption advice may cover specific fish species and size ranges that might not align with legal possession limits under Ontario’s fishing regulations. Before you fish, always ensure:
- Fishing is permitted in the area.
- You possess the necessary fishing license.
- You are aware of any size or catch limits.
Learn more about fishing in Ontario.
Ontario is not unique in having fish consumption advisories. Most regions in North America have similar guidelines in place. Review of consumption restrictions on fish in North America.
For detailed information on the health impacts of contaminants, continue reading.
Map and Consumption Advisories
Utilize our interactive map below to search for and view fish consumption advice for over 2,700 lakes and rivers in Ontario.
Interactive Map Link – This would be replaced with the actual interactive map embed or link.
All consumption advisory data is also publicly accessible on the Open Data Catalogue.
Found a Map Error?
Map inaccuracies can occur. If you identify an error in the location of a lake, river, or stream, please inform us. Use the “Report an error” link within the map pop-up or email us at [email protected] with “Sport Fish Map Error” in the subject line.
Comments and Suggestions
For any comments or suggestions regarding this fish guide, please email us at [email protected].
Understanding the Advisory Tables
After selecting a fishing location on the map, you will be directed to a new webpage displaying fish consumption advisory tables. These tables provide the recommended maximum number of fish meals per month for both general and sensitive populations, categorized by fish species and size (fish length). These recommendations are valid assuming you are not consuming fish from other locations or categories. You can safely eat fish from different categories and locations as long as you carefully track your consumption.
A superscript number next to the fish species name in the tables indicates the primary contaminant(s) influencing the consumption advisory. These contaminants are detailed in the Contaminants in Fish section of this fish guide.
To learn how to effectively use the map to determine safe Ontario fish consumption amounts, refer to the next section: How to Use the Map.
How to Use the Map to Find the Amount of Fish You Can Safely Eat
This fish guide offers specific advice on the number of fish meals per month that are safe to eat, based on the type and size of fish caught at a particular location.
Consumption advice is provided for both the general population and sensitive populations (pregnant individuals, those who may become pregnant, and children under 15 years old).
The consumption advice in this fish guide is determined by:
- The specific lake or river where the fish was caught.
- The species of fish caught.
- The length of the fish, measured from the tip of the nose to the tip of the tail, in centimeters or inches.
Step 1: Locate Your Fishing Spot on the Interactive Map
Visit the interactive map and enter the name of the lake or river where you fished into the search bar. Alternatively, you can manually navigate the map to find your location.
Click on the yellow circle representing your location to open a pop-up window. In the pop-up, select “Consumption advisory table.” This action will open a new webpage displaying the fish consumption advisory information for your chosen location.
Step 2: Identify the Type of Fish
Determine and select the type of fish you caught from the advisory table. If you are unsure about the fish species, consult the “Learn How to Identify Fish” section of this fish guide.
Step 3: Measure the Fish Length
Measure the total length of the fish from the tip of its nose to the tip of its tail, using either centimeters or inches. In the advisory table for the fish species you identified, locate the appropriate length range:
- The top row indicates length ranges in centimeters.
- The second row indicates length ranges in inches.
Example: Fish Consumption Advisory Table for Walleye from Lake [Lake Name]
| Length (cm) | 15–20 | 20–25 | 25–30 | 30–35 | 35–40 | 40–45 | 45–50 |
|---|---|---|---|---|---|---|---|
| Length (in) | 6–8 | 8–10 | 10–12 | 12–14 | 14–16 | 16–18 | 18–20 |
| General population | N/A | N/A | N/A | 8 | N/A | N/A | 4 |
| Sensitive population* | N/A | N/A | N/A | 4 | N/A | N/A | 0 |
Note: If an angler catches a 33 cm (13 in) Walleye from Lake [Lake Name], the table advises a maximum of 8 meals per month for the general population and 4 meals per month for sensitive populations for Walleye in the 30-35 cm (12–14 in) range. Use the scroll bar at the bottom of the table if necessary to find the correct length range.
Step 4: Understand the Recommended Meals Per Month
The third and fourth rows of the advisory table indicate the recommended number of meals per month for the general and sensitive populations, respectively.
Find the number in the table corresponding to the size range of the fish you caught. This number represents the maximum number of meals of that size of fish, from that specific location, that can be safely consumed each month, assuming no fish from other locations or categories are eaten.
For example, for a 33 cm (13 inches) Walleye caught in Lake [Lake Name]:
- The general population is advised to eat no more than 8 meals per month.
- The sensitive population is advised to eat no more than 4 meals per month.
Step 5: Track Your Monthly Fish Consumption
Keep a record of your total monthly fish meals to ensure you don’t exceed 100% of your advised monthly consumption limit.
You can combine fish meals from different categories and locations, but it is crucial to track your intake.
The table below helps convert the number of fish meals per month into a percentage of your total monthly intake.
Monthly Fish Meals Conversion Table
| Category (Number of fish meals per month) | Fraction of monthly intake total | Percentage of monthly intake total% |
|---|---|---|
| 32 | 1⁄32 | 3.1 |
| 16 | 1⁄16 | 6.3 |
| 12 | 1⁄12 | 8.3 |
| 8 | 1⁄8 | 12.5 |
| 4 | 1⁄4 | 25 |
| 2 | 1⁄2 | 50 |
| 1 | 1 | 100 |
Example: If you consume:
- Two meals from the 12-meal-per-month category, each meal represents 8.3% of your monthly limit (2 meals × 8.3% = 16.6%).
- One meal from the 2-meal-per-month category, that meal represents 50% of your monthly limit.
The combined total consumption is 66.6% of your 100% monthly limit, leaving room for more fish consumption within the safe limit.
Fish Fillet Serving Sizes
Our consumption advice is based on a standard fish meal size of 227 grams (8 ounces, or half a pound), which is approximately a dinner plate-length fillet for an average adult weighing 70 kilograms (154 pounds).
Visual Guide to Fish Serving Sizes
Use your palm as a visual guide to estimate fish serving sizes:
- Half of your palm: Approximately 2 ounces of fish.
- Your whole palm: Approximately 4 ounces of fish.
- Your palm including fingers: Approximately 8 ounces of fish (half a pound, a dinner plate-length fillet, or the standard 227-gram meal used for consumption advice).
The following table helps relate the number of fish fillets to the recommended number of meals in our advisory tables. Remember, one fish yields two fillets.
Fish Conversion Table by Length
| Fish species | 15 cm / 6 in | 20 cm / 8 in | 25 cm / 10 in | 30 cm / 12 in | 35 cm / 14 in | 40 cm / 16 in | 45 cm / 18 in | 50 cm / 20 in | 55 cm / 22 in | 60 cm / 24 in | 65 cm / 26 in | 70 cm / 28 in | 75 cm / 30 in |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Atlantic Salmon | N/A | N/A | N/A | N/A | N/A | N/A | N/A | 0.5 | 0.4 | 0.3 | 0.2 | 0.2 | 0.1 |
| Bigmouth Buffalo | N/A | N/A | N/A | N/A | 1.8 | 1.2 | 0.8 | 0.6 | 0.4 | 0.3 | 0.2 | N/A | N/A |
| Black Crappie | 34 | 14 | 7 | 4 | 2.7 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Bluegill | 19 | 7 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Brook Trout | 25 | 10 | 5 | 3 | 1.9 | 1.3 | 0.9 | 0.6 | 0.5 | N/A | N/A | N/A | N/A |
| Brown Bullhead | 33 | 14 | 7 | 4 | 2.5 | 1.7 | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Brown Trout | 22 | 9 | 4 | 2 | 1.4 | 0.9 | 0.6 | 0.5 | 0.3 | 0.3 | 0.2 | 0.2 | 0.1 |
| Channel Catfish | 40 | 16 | 7 | 4 | 2.5 | 1.6 | 1.1 | 0.8 | 0.6 | 0.4 | 0.3 | 0.3 | 0.2 |
| Chinook Salmon | N/A | 9 | 5 | 3 | 1.7 | 1.1 | 0.8 | 0.6 | 0.4 | 0.3 | 0.2 | 0.2 | 0.2 |
| Cisco(Lake Herring) | 38 | 15 | 7 | 4 | 2.4 | 1.5 | 1.0 | 0.7 | 0.5 | N/A | N/A | N/A | N/A |
| Coho Salmon | N/A | N/A | 4 | 3 | 1.6 | 1.1 | 0.7 | 0.5 | 0.4 | 0.3 | 0.2 | 0.2 | 0.2 |
| Common Carp | 27 | 11 | 6 | 3 | 2.1 | 1.4 | 1.0 | 0.7 | 0.5 | 0.4 | 0.3 | 0.3 | 0.2 |
| Freshwater Drum | 47 | 19 | 9 | 5 | 3.0 | 1.9 | 1.3 | 0.9 | 0.7 | 0.5 | 0.4 | 0.3 | 0.3 |
| Gizzard Shad | 33 | 14 | 7 | 4 | 2.4 | 1.5 | 1.1 | N/A | N/A | N/A | N/A | N/A | N/A |
| Goldeye | N/A | 22 | 10 | 5 | 2.8 | 1.7 | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Goldfish | N/A | 6 | 4 | 2 | 1.7 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Lake Trout | N/A | 12 | 6 | 3 | 2.1 | 1.3 | 0.9 | 0.7 | 0.5 | 0.4 | 0.3 | 0.2 | 0.2 |
| Lake Whitefish | 29 | 12 | 6 | 3 | 2.0 | 1.3 | 0.9 | 0.6 | 0.5 | 0.4 | 0.3 | 0.2 | N/A |
| Largemouth Bass | 24 | 10 | 5 | 3 | 1.7 | 1.1 | 0.8 | 0.6 | N/A | N/A | N/A | N/A | N/A |
| Ling (Burbot) | N/A | 32 | 16 | 9 | 5.9 | 4.0 | 2.8 | 2.0 | 1.5 | 1.2 | 0.9 | 0.7 | 0.6 |
| Longnose Sucker | N/A | 14 | 7 | 4 | 2.6 | 1.8 | 1.3 | 0.9 | 0.7 | 0.5 | N/A | N/A | N/A |
| Mooneye | N/A | 11 | 6 | 4 | 2.4 | 1.7 | 1.2 | 0.9 | 0.7 | N/A | N/A | N/A | N/A |
| Northern Pike | N/A | N/A | 17 | 10 | 6.0 | 4.0 | 2.8 | 2.0 | 1.5 | 1.2 | 0.9 | 0.7 | 0.6 |
| Pink Salmon | N/A | N/A | N/A | 3 | 2.0 | 1.3 | 0.9 | 0.6 | 0.5 | N/A | N/A | N/A | N/A |
| Pumpkinseed | 16 | 7 | 3 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Quillback Carpsucker | 11 | 6 | 3 | 2 | 1.6 | 1.2 | 0.9 | 0.7 | 0.6 | N/A | N/A | N/A | N/A |
| Rainbow Smelt | 33 | 14 | 8 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Rainbow Trout | N/A | 8 | 4 | 3 | 1.7 | 1.1 | 0.8 | 0.6 | 0.4 | 0.3 | 0.3 | 0.2 | 0.2 |
| Redhorse Sucker | 30 | 12 | 6 | 3 | 2.1 | 1.4 | 1.0 | 0.7 | 0.5 | 0.4 | 0.3 | 0.2 | N/A |
| Rock Bass | 25 | 11 | 6 | 4 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Round Whitefish | N/A | 18 | 9 | 5 | 2.8 | 1.8 | 1.2 | 0.8 | 0.6 | N/A | N/A | N/A | N/A |
| Sauger | 39 | 16 | 8 | 5 | 2.9 | 1.9 | 1.3 | 1.0 | 0.7 | 0.5 | N/A | N/A | N/A |
| Siscowet | N/A | N/A | N/A | 4 | 2.3 | 1.4 | 1.0 | 0.7 | 0.5 | 0.3 | 0.3 | 0.2 | 0.2 |
| Smallmouth Bass | 35 | 14 | 7 | 4 | 2.4 | 1.6 | 1.1 | 0.8 | 0.6 | N/A | N/A | N/A | N/A |
| Splake | 27 | 10 | 5 | 3 | 1.7 | 1.1 | 0.7 | 0.5 | 0.4 | 0.3 | 0.2 | 0.2 | N/A |
| Walleye | 37 | 15 | 7 | 4 | 2.6 | 1.7 | 1.2 | 0.8 | 0.6 | 0.5 | 0.4 | 0.3 | 0.2 |
| White Bass | 41 | 17 | 8 | 5 | 3.0 | 2.0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| White Crappie | 37 | 16 | 9 | 5 | 3.4 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| White Perch | 37 | 15 | 7 | 4 | 2.4 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| White Sucker | 35 | 14 | 7 | 4 | 2.6 | 1.7 | 1.2 | 0.9 | 0.6 | 0.5 | N/A | N/A | N/A |
| Yellow Perch | 25 | 10 | 5 | 3 | 1.8 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
For example, if the consumption advisory for a 30 cm Brook Trout is 2 meals per month, and the table indicates one meal is roughly equivalent to 3 fillets, you could safely eat 6 Brook Trout fillets per month (2 meals/month × 3 fillets/meal = 6 fillets/month).
Interpreting Consumption Advice for the General Population
Advice for the general population is based on a 227-gram (8-ounce) meal of skinless, boneless dorsal fillet, suitable for an average adult weighing 70 kg (154 pounds). Portion sizes should be adjusted accordingly for individuals of different sizes. If your meal is significantly larger than 227 grams, consume fewer meals than recommended.
Refer to “General Advice to Reduce Risks When Eating Fish” in this fish guide for further information.
Interpreting Consumption Advice for Sensitive Populations
Sensitive populations include:
- Pregnant individuals or those who may become pregnant.
- Children under 15 years of age.
These groups are more susceptible to contaminants like mercury and PCBs. This fish guide advises sensitive populations to:
- Choose fish with consumption advisories of four to 32 meals per month.
- Avoid fish with advisories of less than four meals per month.
Consult “Advice for Sensitive Populations” for guidance on reducing contaminant risks when consuming both Ontario-caught and store-bought fish.
Fish Sizes Outside the Advisory Table Range
Advisory tables may not include all fish types and sizes. Contaminant levels generally increase with fish size. Use these guidelines for fish sizes not listed:
- Smaller fish: Follow the advice for the smallest tested size range.
- Larger fish: Limit consumption of fish larger than the table’s range.
For specific questions about safe consumption amounts, contact the Fish Contaminant Monitoring Program.
General Advice on How to Reduce Your Risk When Eating Fish
Quick Tips for Reducing Contaminant Risk
- Choose Smaller Fish: Smaller fish generally have lower contaminant levels than larger fish of the same species.
- Select Leaner Fish from the Great Lakes: Species like Bass, Pike, Walleye, Perch, and panfish tend to be less contaminated than fatty fish like Salmon and Trout. Grill or bake fatty fish on a rack to allow fat and contaminants to drip away.
- Opt for Panfish or Whitefish from Inland Waters: Top predators like Pike and Walleye often have higher contaminant levels compared to panfish or whitefish.
Fish Organs
Avoid eating fish organs, as they can accumulate high levels of heavy metals, pesticides, and algal toxins.
Fish Eggs
Fish eggs, particularly from fatty fish like Great Lakes Salmon and Trout, can contain elevated levels of organic contaminants due to their high fat content. Do not consume eggs from these fatty fish.
Fish with Abnormalities
Fish may sometimes have worms, grubs, cysts, tumors, or lesions. Parasites are normal and not a health hazard if the fish is properly cooked. Tumors and lesions are often due to viral or bacterial infections and do not significantly alter contaminant levels. However, it is generally advisable to avoid eating fish that appear sick, dying, or dead.
Algal Blooms
Blue-green algae blooms can produce toxins called microcystins. While these toxins do not significantly accumulate in fish fillets, they can be found in fish livers. Adhering to the advice of not eating fish organs mitigates this risk.
Freshwater Clams
Avoid eating freshwater clams as they can harbor harmful bacteria and pathogens, despite generally being low in contaminants.
Contaminants from Store-Bought Fish
While most store-bought fish are low in contaminants, sensitive populations should take extra precautions:
- Reduce Ontario-caught fish consumption by one meal per month for every two meals of store-bought fish (including canned fish).
- Avoid Ontario-caught fish if also consuming Shark, Swordfish, or fresh/frozen Tuna regularly, as Health Canada recommends limiting these high-mercury fish.
For more advice on store-bought fish, contact [relevant authority/link].
Preserving and Preparing Fish for Cooking
To ensure safety and reduce contaminants:
- Chill freshly caught fish immediately on ice or in a refrigerator to prevent spoilage.
- Clean, dress, and refrigerate or preserve fish as quickly as possible.
Cleaning and Cooking to Reduce Contaminants
Fatty fish like Salmon, Trout, Carp, and Catfish tend to accumulate higher levels of PCBs, pesticides, and dioxins. Before cooking:
- Remove the skin.
- Trim fatty areas.
- Discard belly flesh.
Cooking methods like grilling, broiling, or baking on a rack allow fat and contaminants to drip away. Avoid reusing oil when deep-frying fish.
Unfortunately, contaminants like mercury and PFAS are distributed evenly throughout the fish flesh and cannot be reduced by cleaning or cooking methods.
Contaminants in Fish
Fish contaminants can originate from local and distant sources, traveling through air and precipitation. Mercury, PCBs, and toxaphene are known for long-range transport, causing low-level contamination even in remote areas.
While testing covers a wide range of contaminants, consumption advisories are primarily due to mercury and PCBs. Superscript numbers in advisory tables indicate the contaminant(s) of concern.
1. Mercury
Mercury converts to methylmercury and is absorbed by fish through gills and diet. It accumulates over time, with top predators like Walleye and Pike typically having the highest levels.
2. Polychlorinated Biphenyls (PCBs)
PCBs are persistent industrial chemicals banned in the 1970s but remain in the environment, accumulating in aquatic ecosystems.
3. Dioxin-like PCBs
These are a subset of PCBs with dioxin-like toxicity.
4. Dioxins and Furans
Dioxins and furans are byproducts of industrial processes and incomplete combustion, with 17 toxic forms of concern.
5. Toxaphene
Toxaphene is a persistent insecticide banned in Canada in 1974 and restricted in the US in 1982.
6. Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)
PFAS are chemicals used in water, stain, and oil repellents since the 1950s. They persist in the environment, and restrictions are often found downstream from firefighting foam usage areas.
7. Selenium
Selenium is a metal occasionally found at levels requiring consumption advisories.
8. Arsenic
Arsenic is a metal occasionally found at levels requiring consumption advisories.
9. Polybrominated Diphenyl Ethers (PBDEs)
PBDEs are flame retardants used in various products. Some are now banned or phased out.
10. Polychlorinated Naphthalenes (PCNs)
PCNs are industrial chemicals no longer used in Canada but may be unintentionally produced.
11. Chromium
Chromium is a metal rarely found at levels requiring consumption advisories.
12. Photomirex & 13. Mirex
Mirex is a pesticide used in the southern US, never registered in Canada. Photomirex is a transformation product of mirex.
14. Lead
Lead is a metal occasionally found at levels requiring consumption advisories.
15. Cadmium
Cadmium is a metal rarely found at levels requiring consumption advisories.
16. Tin
Tin is a metal rarely found at levels requiring consumption advisories.
For more information on these contaminants, contact the Fish Contaminant Monitoring Program.
Fish Contaminant Monitoring Program
Location Selection for Testing
Testing every water body in Ontario is impractical due to the vast number of lakes, rivers, and Great Lakes areas. Locations are selected based on factors like:
- Popularity for fishing
- Known or suspected pollution sources
- Importance as a food source
- Recreational or industrial development
- Partnership opportunities
- Long-term monitoring programs
Location selection is ongoing. Input on testing sites can be provided via email at [email protected].
Fish Species Selection for Testing
Species selection considers contaminant accumulation rates, which vary based on:
- Diet
- Habitat
- Growth rate
- Physiological differences
Top predators like Walleye and Pike are tested first for mercury due to their higher accumulation potential. For organic contaminants, fatty species like Salmon, Trout, Carp, and Catfish are prioritized.
Fish Collection and Testing Methods
Fish samples are collected and tested by:
- Ministry of Natural Resources and Forestry
- Ministry of the Environment, Conservation and Parks
- Other agencies
Samples ideally include 10+ fish per species, representing the size range in the location. Length, weight, and sex are recorded. Skinless, boneless dorsal fillets are analyzed for contaminants at the Ministry of the Environment, Conservation and Parks laboratory in Toronto. Consumption advisories are only provided for tested species at specific locations.
Location Retesting Schedule
The Fish Contaminant Monitoring Program continuously adds new locations and retests existing ones since the mid-1970s. Retesting frequency depends on contaminant levels and fishing popularity:
- High or changing contaminant levels: Retested every 1-5 years.
- Popular fishing areas with stable contaminant levels: Retested every 5-20 years.
- Remote, low-pollution areas with stable levels: Retested every 10-50 years.
Learn How to Identify Fish
This fish guide includes information to help you identify common Ontario fish species. Visit the species page to learn more about identifying your catch accurately. [Link to Fish Identification Resources]
Prohibited and Restricted Species
Consult the Ontario Fishing Regulations Summary for legal fishing information on species like:
Muskellunge
Catch and release is encouraged for Muskellunge due to population vulnerability. They also tend to have high mercury levels and should not be consumed.
Lake Sturgeon
Recreational fishing for Lake Sturgeon is restricted in threatened populations. Catch and release is permitted in non-threatened areas.
American Eel
Recreational fishing for American Eel is prohibited as they are endangered. If caught, they must be released. Sightings can be reported to the Natural Heritage Information Centre. [Link to Reporting Sightings]
Learn to Fish
The Learn to Fish Program is a free program for new anglers in Ontario, offering family-friendly fishing experiences and lessons.
