Long Lake

Where Long Lake is

Long Lake lies in the District of Sudbury, within the City of Greater Sudbury.

How deep is Long Lake?

Long Lake reaches a maximum recorded depth of 38.5 meters, determined from 57,928 soundings.

Surveyed Depths

Ontario has surveyed the depths of several thousand of its lakes over more than half a century. Later surveys were conducted by boat with satellite positioning and produced hundreds of thousands of soundings per lake. Earlier surveys were charted by running transects across the water and drawing depth contours by hand.

Water quality

Ontario’s Lake Partner Program is a volunteer monitoring network. Participants collect a water sample each spring for phosphorus analysis and measure water clarity through the summer with a Secchi disk.

Phosphorus is the nutrient that controls how much algae a lake can grow. A lake with little phosphorus stays clear and supports cold-water fish such as lake trout. As phosphorus rises, algae increase, the water clouds, and oxygen in the deep water falls as the algae decay. The province classifies each monitoring site by its spring phosphorus. Below 10 micrograms per litre is oligotrophic: clear water and low algae. From 10 to 20 is mesotrophic: moderately productive water, with more algae and weed growth than an oligotrophic lake but rarely a bloom. Above 20 is eutrophic: nutrient-rich water, prone to algal blooms and low oxygen at depth.

A Secchi disk is a 20 centimeter white or black-and-white plate lowered on a marked line until it disappears from view. The depth at which it vanishes is the Secchi depth, a direct measure of water clarity. Clearer water gives a deeper reading.

Long Lake has 13 Lake Partner monitoring sites. Nine have reported phosphorus for the three or more years the province requires before a status is assigned. Seven of those sites are classified oligotrophic and two mesotrophic.

The longest record is held by site 2784/8 at NE End, deep spot, sampled over 13 springs to 2025. Its long-term mean phosphorus concentration is 8.55 micrograms per litre, within the oligotrophic band, which extends to 10. The site’s 157 clarity readings give a median Secchi depth of 4.0 meters.

Fish in Long Lake

Ontario’s aquatic resource records name 16 fish species in Long Lake. The province classes the lake as warm water. The record took effect on 1 November 2017, and it compiles what field biologists had reported by then. The province’s other records for the lake name one further species, brook trout. It appears in the records below.

Nine of the seventeen species in the province’s records

• Lake Trouttrout and whitefish
• Ciscotrout and whitefish
• Northern Pikepike
• Walleyeperch
• Yellow Perchperch
• Smallmouth Basssunfish
• Largemouth Basssunfish
• Pumpkinseedsunfish
• Brown Bullheadcatfish

Stocking history

Ontario’s stocking records for Long Lake run from 1946 to 2005 and hold 54 releases. Walleye account for most of the fish: 2,585,600 released in ten of the years between 1946 and 2005. The last recorded release was 10,000 walleye fingerlings in 2005.

The province’s current stocking programme, recorded from 2016, lists no release into Long Lake.

Eating the fish

The 2025 Guide to Eating Ontario Fish carries consumption advice for eight species taken from Long Lake, tested for contaminants at a sampling location in Eden & Broder Twps., Sudbury Dist. Each figure below is the most meals a month the guide advises for a fish of that length. The advice falls as the fish gets longer, because mercury accumulates over a fish’s life. A zero means the guide advises no meals of that fish at that size.

General population adultsSensitive population children under fifteen, women who are or may become pregnant

Fisheries Management Zone 10

Long Lake lies in Fisheries Management Zone 10. Ontario sets its fishing seasons and catch limits by zone.

The figures are the number of fish an angler may catch and keep in a day and have in possession, under a sport fishing licence and under a conservation licence. The rows are the whole zone’s, and they apply to every lake in it. No waterbody exception names Long Lake.

Long Lake Ice Fishing

An ice hut on Long Lake must be removed by March 31. Long Lake lies in fisheries management zone 10, one of the twenty zones Ontario sets its fishing rules by, and one removal date applies across the whole zone.

An ice hut must also be removed before the ice breaks up, whether or not that date has passed. The deadline clears huts from the ice ahead of the thaw and does not close the fishing season.

Registration is required in zone 10 for an ice hut built of anything other than fabric, and for a fabric tent covering seven square meters or more. Registration is free, and the number is displayed on the outside of the hut.

Ice conditions

No public record reports the thickness or the condition of the ice on Long Lake on any given day. Ontario publishes ice safety guidance for anyone going out on the ice, at ontario.ca.

Islands and names

Long Lake contains 12 islands in the Ontario Hydro Network’s outline, zero of them over 10 hectares and eight under a tenth of a hectare.

Official names

Ontario’s geographic names register lists 3 official names on the water and its islands: 1 island.

Nearby lakes

• Nepahwin Lake14 km away
• Ramsey Lake17 km away
• Richard Lake17 km away
• Lake Panache24 km away

All lakes

Questions about Long Lake

• How deep is Long Lake?

  Its maximum recorded depth is 38.5 meters.

• How big is Long Lake?

  Its surface covers 8.7 square kilometers and it holds 12 islands. Of its 52 kilometers of shoreline, 50 kilometers is the mainland shore and 2 kilometers is the shore of the islands.

• What fish are in Long Lake?

  Ontario’s aquatic resource records name sixteen species, among them lake trout, walleye, smallmouth bass, largemouth bass, northern pike and yellow perch. The lake’s spawning, consumption and stocking records also name brook trout.