Sign inSign up free Sign inSign up free Sign inSign up freeLake depth chart
Today's read
Recent public catches load as you reach this section.
149-acre lake in Nipissing District, Ontario. The lake tops out around 59 ft. The depth chart comes from Ontario Ministry of Natural Resources and Forestry bathymetric survey data, so the contours are survey-derived rather than computer-modeled. The depth data here comes from the Ontario MNRF survey of 1980 (a transect sounding survey). What the data behind the map says about each species, season by season:
The drawn water covers 150 acres wrapped in 6.1 miles of bank, broken up by 2 islands. A development index of 3.5 means a maze of bays and points: far more casting targets than a round bowl of the same size. 77% of the surface is littoral (under ~15 ft) — cover, weeds and forage water. Call it 2.5 mi long by 0.3 mi wide at the broadest reach. It sits in Nipissing District. If the bite dies, Doe Lake is 2 mi to the southeast.
These fish are listed in an exact-water agency record as forage or ecological context. They are not target-species profiles and do not affect DepthScout's Prime, Good, or Fair spot ratings.
Official Ontario MNRF Fish ON-Line record. The listing documents source-recorded presence, not present abundance or guaranteed catchability.
Start shallow in spring: cisco (lake herring) sit in 10 to 40 ft that time of year. Summer pushes them deeper, 18 to 59 ft, and winter fish settle into 18 to 59 ft. The spot to know is Deep basin, a deep basin in about 53 ft of water that rates prime for cisco (lake herring) in summer. Warm-month bites cluster around early morning. Throw a vertical flutter spoon (small) or a drop-shot micro plastic until the fish tell you otherwise.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Deep basin (53 ft) | Small silver spoon, Tiny swim jig (white) |
| Summer | 18 to 59 ft chart-limited; documented 40 to 80 ft | dawn | Deep basin (53 ft) | Vertical flutter spoon (small), Drop-shot micro plastic |
| Fall | 5 to 25 ft | dusk & dawn | Break off the point (7 ft) | Small casting spoon, Inline spinner (silver) |
| Winter | 18 to 59 ft chart-limited; documented 20 to 60 ft | dawn | Deep basin (53 ft) | Small jigging spoon (glow/silver), Tungsten jig + minnow head |
In spring, walleye run shallow here, mostly 4 to 15 ft. Midsummer fish sit out in 15 to 35 ft before dropping to 20 to 40 ft for winter. Fall walleye concentrate at Break off the point, a prime-rated drop-off around 7 ft. Fish it in the evening and early morning and you'll meet the bite. You won't need more than a crawler harness on bottom bouncer or a deep crankbait (trolled) most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | Main-lake point (7 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Shallow feeding flat (14 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Break off the point (7 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | open water | Jigging spoon + minnow head, Rattle bait |
The spring pattern is a shallow one: yellow perch in 3 to 12 ft. Midsummer fish sit out in 10 to 30 ft before dropping to 15 to 35 ft for winter. The spot to know is Shallow bay flat, a weed flat in about 3 ft of water that rates prime for yellow perch in spring. Plan around early morning in the warm months. Summer baits: a drop-shot micro plastics or a small spoon tipped with worm gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Shallow bay flat (3 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Break off the point (7 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (7 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Shallow feeding flat (14 ft) | Tungsten jig + spikes, Rattle spoon (small) |
When the water first warms, northern pike slide up into 2 to 8 ft. Summer is an 8 to 20 ft game here, winter a 5 to 15 ft one. Start at Shallow bay flat. It's a weed flat holding about 3 ft of water and rates prime come spring. The feeding windows run early morning and the evening. Keep a bucktail or a weedless spoon over cabbage rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (3 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Shallow feeding flat (14 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Break off the point (7 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow feeding flat (14 ft) | Tip-ups, Large jigging spoon |
Start shallow in spring: rock bass sit in 2 to 10 ft that time of year. Summer pushes them deeper, 5 to 20 ft, and winter fish settle into 12 to 30 ft. The spot to know is Main-lake point, a point in about 7 ft of water that rates prime for rock bass in summer. Warm-month bites cluster around the evening. Throw a ned rig (small) or a marabou jig until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | midday & dawn | Main-lake point (7 ft) | 1/16 oz jig + grub, Small inline spinner |
| Summer | 5 to 20 ft | dusk | Main-lake point (7 ft) | Ned rig (small), Marabou jig |
| Fall | 8 to 22 ft | midday | Break off the point (7 ft) | Small tube jig, Inline spinner |
| Winter | 12 to 30 ft | midday | Break off the point (7 ft) | Tungsten jig + plastic, Small spoon + spike |
Come spring, look for brown bullhead tight to the bank in 2 to 8 ft. Expect a summer slide to 3 to 12 ft, then a winter hold in 10 to 25 ft. Start at Shallow bay flat. It's a weed flat holding about 3 ft of water and rates prime come spring. Prime time lands in after dark and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | dusk & night | Shallow bay flat (3 ft) | |
| Summer | 3 to 12 ft | night & dusk | Shallow bay flat (3 ft) | |
| Fall | 5 to 15 ft | dusk | Shallow feeding flat (14 ft) | |
| Winter | 10 to 25 ft | midday | open water |
Mercer Lake also holds largemouth bass (8 to 20 ft in summer), pumpkinseed (2 to 10 ft in summer), smallmouth bass (10 to 30 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Count 7 structure marks on this chart. The deepest, Deep basin, sits near 53 ft.
Access data: Geospatial Ontario - Fishing Access Points; Government of Ontario - MNR Unpatented Crown Land Shoreline; Government of Ontario - MNR Unpatented Crown Land Shoreline. Confirm conditions and fees locally before you launch.
Season dates, license requirements, and size and bag limits for Ontario waters are set by the Ontario fishing regulations (FMZ summary) — and special regulations can apply to Mercer Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Mercer Lake is about 59 ft (18 m) deep at its deepest point. The depth data here comes from the Ontario MNRF survey of 1980 (a transect sounding survey).
Anglers target cisco (lake herring), walleye, yellow perch, northern pike, rock bass, brown bullhead, largemouth bass, pumpkinseed, smallmouth bass on Mercer Lake.
Deep basin is the top-rated area: a deep basin in about 53 ft of water that rates prime for cisco (lake herring) in summer. Scroll up to the map for the complete spot list by species and season.
For cisco (lake herring), the summer bite is best in early morning. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.
Fishing on Mercer Lake is regulated by the Ontario fishing regulations (FMZ summary). Check the official Ontario regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Doe Lake 2 mi · Porcupine Lake 4 mi · Scollard L. 44 5 mi · Rabbit Lake 6 mi · Bear Lake 6 mi · Ethier Lake 7 mi · Number Two Lake 8 mi · Number One Lake 9 mi · North Channel (French River) 9 mi · Byrne Lake 12 mi · Bear Lake 12 mi · Bluegill L. 12 mi
See how Mercer Lake stacks up: best largemouth bass lakes in Ontario · best smallmouth bass lakes in Ontario · best walleye lakes in Ontario · best northern pike lakes in Ontario
More water nearby: Nipissing District fishing maps (683 charts). Browse all Ontario fishing maps. See every water on DepthScout. Bathymetry: published agency survey data. How we build these maps. Fish here with a sonar unit that logs? Send us your depth data and we'll improve this chart, credited to you. For fishing guidance only, never navigation.