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83,766-acre Shannon Estuary. Mouth North saltwater fishing map with official INFOMAR survey bathymetry, measured-cell fishing spots, official fish evidence, seasonal forage guidance, access context and current-rule links. The mouth north trip-scale survey reach of Shannon Estuary, retaining only official survey-backed seabed cells that pass the Ireland release gates. The water tops out around 311 ft. The depth chart comes from INFOMAR (Geological Survey Ireland and Marine Institute) bathymetric survey data, so the contours are survey-derived rather than computer-modeled. What the data behind the map says about each species, season by season:
Drawn out, this is 83,862 acres of water rimmed by 46.5 miles of bank. Its 1.1 shoreline index means few bank features; the contours below do the pattern work. The shallow band under 15 ft claims about 0% of the surface — that's where the groceries are. The basin spans about 15.7 mi end to end and 13.1 mi across at its widest. The nearest mapped water is Shannon Estuary - Mouth South, 12 mi to the south.
Marine Institute spawning, nursery, observation and range layers support the principal surveyed pelagic and groundfish. IFI's national and regional sea-angling publications support additional habitat-compatible recreational targets. This is occurrence and search guidance, not equal abundance, a section-level population estimate or a promised catch. The roster may combine exact-water monitoring with habitat-filtered official regional evidence; it does not imply that every species is equally abundant throughout the mapped section.
| Species | Evidence basis | Count / date |
|---|---|---|
| Bass (European Seabass) | official species listing | — |
| Mackerel (Atlantic Mackerel) | official species listing | — |
| Herring (Atlantic Herring) | official species listing | — |
| Whiting (Whiting) | official species listing | — |
| Flounder (European Flounder) | official species listing | — |
| Plaice (European Plaice) | official species listing | — |
| Sole (Common Sole) | official species listing | — |
| Thornback ray (Thornback Ray) | official species listing | — |
| Thick-lipped grey mullet (Thick-lipped Grey Mullet) | official species listing | — |
| Garfish (Garfish) | official species listing | — |
| Sea trout (Sea Trout) | official species listing | — |
Official species-evidence source.
In spring, european seabass run shallow here, mostly 3 to 25 ft. Midsummer fish sit out in 2 to 30 ft before dropping to 10 to 55 ft for winter. Fish it in early morning and the evening and you'll meet the bite. You won't need more than a surface lure or a paddle-tail soft plastic most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 25 ft | dawn & dusk | open water | Paddle-tail soft plastic, Shallow minnow plug |
| Summer | 2 to 30 ft | dawn & dusk | open water | Surface lure, Paddle-tail soft plastic |
| Fall | 4 to 40 ft | dawn & dusk | open water | Slim metal lure, Minnow plug |
| Winter | 10 to 55 ft | midday | open water | Slow soft-plastic shad, Suspending minnow |
Early season atlantic mackerel use the shallows, holding in 5 to 45 ft. Summer is a 15 to 80 ft game here, winter a 30 to 120 ft one. The chart's best answer is Sharp break — drop-off, 121 ft, good for winter. Best bite is early morning and the evening. Tie on a feather rig or a small vertical jig and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 45 ft | dawn & dusk | open water | Mackerel feather rig, Small silver jig |
| Summer | 15 to 80 ft | dawn & dusk | Shoreline point (60 ft) | Feather rig, Small vertical jig |
| Fall | 10 to 65 ft | dawn & dusk | Shoreline point (60 ft) | Compact silver jig, Sparse feather rig |
| Winter | 30 to 120 ft | midday | Sharp break (121 ft) | Small deep jig |
In spring, atlantic herring run shallow here, mostly 5 to 25 ft. Midsummer fish sit out in 15 to 50 ft before dropping to 20 to 60 ft for winter. Fish it in early morning and the evening and you'll meet the bite. You won't need more than a herring feather rig or a small silver jig most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 25 ft | dawn & dusk | open water | Small herring feather rig, Micro jig rig |
| Summer | 15 to 50 ft | dawn & dusk | open water | Herring feather rig, Small silver jig |
| Fall | 10 to 40 ft | dawn & dusk | open water | Small feather rig, Compact silver spoon |
| Winter | 20 to 60 ft | midday | open water | Small silver jig, Sparse feather rig |
Spring puts whiting in skinny water — 15 to 55 ft is the zone. As the season builds they drop to 20 to 70 ft, wintering in 15 to 70 ft. Warm-month bites cluster around early morning. A small vertical jig covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 15 to 55 ft | dawn & dusk | open water | Small silver jig, Two-hook feather rig |
| Summer | 20 to 70 ft | dawn | open water | Small vertical jig |
| Fall | 10 to 60 ft | dusk | open water | Small silver jig, Sparse feather rig |
| Winter | 15 to 70 ft | dusk | open water | Compact vertical jig |
Early season european flounder use the shallows, holding in 5 to 25 ft. Summer is a 6 to 35 ft game here, winter a 15 to 50 ft one. Best bite is early morning and the evening. Tie on a bottom jig with spinner blade and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 25 ft | dusk | open water | Small bucktail dragged on bottom |
| Summer | 6 to 35 ft | dawn & dusk | open water | Bottom jig with spinner blade |
| Fall | 8 to 40 ft | dusk | open water | Compact bottom jig |
| Winter | 15 to 50 ft | midday | open water | Small bottom jig |
Spring puts european plaice in skinny water — 8 to 35 ft is the zone. As the season builds they drop to 6 to 40 ft, wintering in 25 to 80 ft. Warm-month bites cluster around early morning and the evening. A light spooned bottom rig or a beaded trace covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 8 to 35 ft | dusk | open water | Beaded flowing trace |
| Summer | 6 to 40 ft | dawn & dusk | open water | Light spooned bottom rig, Beaded trace |
| Fall | 10 to 50 ft | dusk | open water | Beaded bottom trace |
| Winter | 25 to 80 ft | midday | open water |
Shannon Estuary - Mouth North also holds common sole (3 to 30 ft in summer), thornback ray (10 to 65 ft in summer), thick-lipped grey mullet (1 to 18 ft in summer), garfish (2 to 20 ft in summer), sea trout (15 to 50 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Shannon Estuary - Mouth North carries 7 mapped structure features, topping out (or rather bottoming out) at INFOMAR measured basin, about 285 ft down.
The complete Marine Institute Fishing Ports layer returned no port point inside this operational section. DepthScout does not substitute a nearby road, beach or community slipway as verified public fishing access; confirm legal access, parking, tides and local restrictions before visiting.
Private land and private launches need the owner's permission — please ask first.
Season dates, license requirements, and size and bag limits for Ireland waters are set by the Inland Fisheries Ireland (current sea-angling regulations) — and special regulations can apply to Shannon Estuary - Mouth North specifically, so confirm the current rules before you fish. Check the current national and water-specific rules before every trip, including bass measures, the 2026 recreational pollack controls, salmon and sea-trout licences and river-specific status, protected areas, harbour directions, private land and local signs. A mapped fishing port or measured seabed feature is not permission to fish, park, launch or enter a working harbour.
Check the official Ireland fishing regulations →
Department of Climate, Energy and the Environment (2026 salmon and sea-trout status) →
Check special-area and water-specific rules →
Check official shore-access information →
Shannon Estuary - Mouth North is about 311 ft (95 m) deep at its deepest point. The depth chart comes from INFOMAR (Geological Survey Ireland and Marine Institute) bathymetric survey data, so the contours are survey-derived rather than computer-modeled.
Official coastal monitoring from Marine Institute and Inland Fisheries Ireland informs the european seabass, atlantic mackerel, atlantic herring, whiting, european flounder, european plaice, common sole, thornback ray, thick-lipped grey mullet, garfish, sea trout roster for Shannon Estuary - Mouth North. The mixed roster combines exact-water records where available with habitat-filtered regional evidence; not every species is documented at this exact water, and it is not a promise of equal abundance or a catch on a particular trip.
Sharp break is the top-rated area: a drop-off in about 121 ft of water that rates good for atlantic mackerel in winter. Scroll up to the map for the complete spot list by species and season.
For european seabass, the summer bite is best in early morning and the evening. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.
Fishing on Shannon Estuary - Mouth North is regulated by the Inland Fisheries Ireland (current sea-angling regulations). Check the official Ireland regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Shannon Estuary - Mouth South 12 mi · Shannon Estuary - Lower 12 mi · Tralee Bay - Outer 24 mi · Shannon Estuary - Middle West 26 mi · Galway Bay - Aran West South 27 mi · Galway Bay - Aran East South 29 mi · Shannon Estuary - Middle East 35 mi · Galway Bay - Central West 38 mi · Dingle Bay - Middle 38 mi · Galway Bay - Aran West North 41 mi · Galway Bay - Aran East North 42 mi · Dingle Bay - West North 43 mi
See how Shannon Estuary - Mouth North stacks up: best sea trout lakes in Ireland · best atlantic herring lakes in Ireland · best european flounder lakes in Ireland · best garfish lakes in Ireland
Browse all Ireland fishing maps. See every water on DepthScout. Bathymetry credit: INFOMAR (Geological Survey Ireland and Marine Institute) INFOMAR All Survey bathymetry mosaic (Source-survey vertical references retained in the INFOMAR All Survey mosaic; 100% measured, 0% source-interpolated). 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.