Skip to main content

Atlantic Cod


Atlantic Cod

Atlantic cod is a native Irish sea species with deep roots in the country's coastal fishing culture.

Once widespread around the entire coastline, stocks have declined sharply under commercial pressure, and a big cod is now a genuine achievement rather than a routine catch.

The south coast — particularly the Cork grounds — remains the most productive area for boat anglers targeting wreck and reef fish.

Scientific Name: Gadus morhua

Also known as Codling (fish under 5lb), Trosc (Irish)


Physical Characteristics:
  • Three distinct dorsal fins and two anal fins — no other common Irish sea fish shares this arrangement; a fleshy barbel hangs from the lower jaw.
  • Mottled greenish-brown or sandy flanks with small darker spots; white belly; lateral line curves sharply upward toward the head and is pale, almost white.
  • Fish taken over heavy kelp can run deep red rather than the typical brown — same species, different habitat colouration.
  • Specimen threshold is 7kg (about 15lb 7oz); the Irish record stands at 19.05kg (42lb), taken at Ballycotton in 1921.

What to know

Habitat Distribution

  • Native to Irish waters; found all around the coast but now most reliably encountered on the south coast, particularly the Celtic Sea along the Cork shoreline.
  • Also present in the western Irish Sea, though numbers there have fallen significantly and large fish are scarce.
  • Juveniles favour rocky ground at 30–80m depth; adults move deeper, working wrecks, reefs and the continental shelf edge down to 600m.
  • Smaller codling come into shallower inshore ground — beaches and rocky shorelines — when water temperatures drop in late autumn and winter.

Key Locations

  • Courtmacsherry, Co. Cork — the top venue by ISFC specimen submissions; charter boats work deep reef and wreck ground to the south and west.
  • Kinsale, Co. Cork — consistent producer of specimen fish, with access to productive offshore marks.
  • Ballycotton, Co. Cork — site of the Irish record; still fishes well for boat anglers targeting reef ground.
  • Kilmore Quay, Co. Wexford — one of the better remaining marks on the east coast for decent-sized fish.
  • Shore marks at Youghal and Greystones produce codling in season, particularly through the colder months.

Specific Spots

  • Wrecks and broken reef ground hold the biggest fish — cod use the structure as cover and the baitfish concentrations that come with it.
  • Rocky bottom with kelp holds fish year-round; the weed provides both shelter and a food source in the form of crabs and small fish.
  • On shore marks, fish the deepest water available — gullies, channel edges and drop-offs where bait can be presented hard on the bottom.
  • Sandy beaches adjacent to rocky outcrops can produce codling after dark in winter, when fish push into the surf to feed.

Atlantic Cod FAQ

Answers from onWater's species guide.

What are the best lures and bait for Atlantic Cod?

Natural baits account for most Irish cod: lugworm, ragworm, squid, mackerel fillet and peeler crab are all proven, pennel rigs let you mount larger baits securely for boat work.

When is the best time to fish for Atlantic Cod?

Boat season on the south coast runs broadly from summer through early autumn, July, August and September produce the bulk of specimen fish on wreck and reef ground. Shore codling fishing picks up from November into December as water temperatures drop and smaller fish move inshore.

How do you catch Atlantic Cod?

Most Irish cod fishing is done from charter boats out of south Cork ports, drifting or anchoring over wrecks and reef marks with bait rigs or pirks worked hard on the bottom. Shore anglers target codling from beaches and rocky marks in late autumn and winter, casting bait into deeper gullies after dark.

What do Atlantic Cod eat?

Bottom-dwelling crustaceans, crabs, shrimps and prawns, make up a large part of the diet in Irish and Celtic Sea waters, which is why crab and prawn baits work so well on natural ground. Fish are also a major food source: sand eels, small pollack, whiting and even juvenile cod.

Where do Atlantic Cod live?

Native to Irish waters; found all around the coast but now most reliably encountered on the south coast, particularly the Celtic Sea along the Cork shoreline. Also present in the western Irish Sea, though numbers there have fallen significantly and large fish are scarce.

See it in the app

Most maps show you water.
onWater shows you Atlantic Cod.

  1. 01 · Species map filter

    Map every Atlantic Cod water

    Pick Atlantic Cod and the map zeroes in on the waters they call home. No more guessing which lake holds them.

  2. 02 · Waterbody species

    Tap any water. See what lives there.

    Species, behavior and seasonal patterns for every lake, river and pond, before you leave the driveway.

  3. 03 · Angler Intelligence

    Ask how to catch Atlantic Cod

    Tactics, gear and timing from onWater's AI fishing guide, tuned to the species and the water you're on.

Stop guessing where Atlantic Cod are.

Open the map, filter by Atlantic Cod, and head to water that holds them. Download onWater and plan your next trip in minutes.

  • Species map filter
  • Angler Intelligence
  • Fishing journal

Explore other species

Trout, bass, salmon, panfish and everything in between. Each guide unpacks the behavior, seasons, and tactics that put fish in the net.

No species information available.

Smarter Fishing Starts in the App.

onWater Fish gives you everything you need to plan smarter, fish better, and own every trip from first cast to last.