Coalfish (Coley/Saithe)

By Alex Clayton · Updated 23 October 2026

The coalfish (Pollachius virens) is the fish sold as coley and called saithe in Scotland and Scandinavia. The cheap fillet in the chip shop and the hard-diving fish off a northern rock mark in November are the same species.

It is a cold-water fish, commoner in the north of the UK and the North Sea, and a classic winter shore target. This guide covers the names, telling it from a pollack (the legal sizes differ), records, and shore and boat methods.

Coalfish at a Glance

The key coalfish facts, with the official source named where the figure is a rule or record. For other species on the same coasts, see our UK sea fish species guides.

Fact	Detail
Scientific name	Pollachius virens
Other names	Coley, saithe, coalie; billet and podley for young fish
UK minimum size (MCRS)	35cm, against 30cm for pollack (GOV.UK, updated 3 February 2026)
British boat record	37lb 5oz (16.92kg), D Brown, 1986 (BRFC)
British shore record	24lb 11oz 12dr (11.22kg), M Cammish, 1995 (BRFC)
Maximum recorded size	About 130cm and 32kg (FishBase figures)
Lifespan	16 to 20 years
Best shore season	Typically late October to late March
Key ID feature	Straight, pale lateral line; jaws roughly equal

Local Inshore Fisheries and Conservation Authority (IFCA) byelaws can set different sizes, so check yours.

Coley, Saithe, Billet: Why One Fish Has So Many Names

Are coley and coalfish the same fish? Yes. The Marine Stewardship Council says there is only one species of coley, also known as saithe or coalfish. Local names include:

Coley: fishmongers and chip shops
Saithe: Scotland and Scandinavia
Coalie: angler shorthand
Billet: north-east England, young fish
Podley: Scotland, young fish
Glassan: Northern Ireland
Pysgod Ddu: Welsh
Black jack: another regional name

On the US east coast the same fish is called pollock or Boston blue, which is why American content muddies things. Frozen “pollock” in UK shops is often Alaska pollock, a different fish.

The name a UK angler really needs to separate it from is pollack, with an a.

Coalfish vs Pollack: How to Tell Them Apart

A 33cm fish is legal to keep as a pollack but undersize as a coalfish. The UK minimum sizes are 30cm and 35cm respectively, so the ID decides whether the fish goes in the bag or back in the sea.

Two checks settle it, according to MarLIN, the Marine Biological Association’s species database:

Lateral line. Straight and pale on a coalfish. On a pollack it curves up over the pectoral fin.
Jaw. Roughly equal on a coalfish. A pollack’s lower jaw clearly juts out.

Treat colour as a supporting sign, not proof. Coalfish also have a relatively smaller eye and a tiny or absent chin barbel.

Feature	Coalfish	Pollack
Lateral line	Straight, pale	Curves over the pectoral fin
Lower jaw	Roughly level	Clearly protruding
Back colour	Dark green to black, silver-white flanks	Brown to golden-bronze
UK MCRS	35cm	30cm
Lure colour (angler observation)	Hot orange, lumo green, pink	Responds less to hot colours

For more on the cousin, read our pollack guide or the wider UK sea fish identification guide. If a fish near 35cm leaves you unsure, treat it as a coalfish and put it back.

How Big Do Coalfish Get? Sizes and British Records

The British shore coalfish record has stood since 1995, and the boat record since 1986.

Angling guides disagree on typical sizes. One puts shore fish at 2lb to 10lb, another calls 1lb to 4lb average and a double-figure fish excellent from the shore. From boats, over 15lb is a specimen and 20lb-plus is huge in UK waters.

Adults typically reach 100cm to 120cm, live 16 to 20 years and mature at 4 to 9.

The British Record (rod-caught) Fish Committee list (June 2026) gives:

Boat: 37lb 5oz, D Brown, 1986, wreck south of Eddystone off Plymouth
Shore: 24lb 11oz 12dr, M Cammish, 1995, Filey Brigg, Yorkshire

Boat claims are now by length only (qualifying at 105cm), the weight list having been frozen in June 2024. Shore length claims qualify at 60cm. Check the current list before claiming.

Where and When to Find Coalfish

On the south coast a coalfish is a rarer catch. It is a cold-water species, commoner in the north and the North Sea though found round the UK and Ireland, and Channel numbers are reported to have fallen since the early 1980s.

Look for rock and broken ground, not open sand. Small fish move in loose shoals, while the biggest sit alone on wrecks, reef pinnacles and deep rough ground.

Young fish eat worms, mussels, small crabs and sandeels. Adults mostly eat fish but still pick crabs and worms off the bottom, so bait works as well as lures.

Open-coast shore fishing typically runs from late October to late March, best north of a rough line from North Wales to the north-east. Small billet stay in harbours and estuaries all year, and adults move offshore in spring to spawn.

Shore fish feed best on the flood, especially rising tides in the days before springs, often on the same rough-ground winter marks anglers fish for cod.

How to Catch Coalfish from the Shore

You do not need long-range casting gear. Talk Sea Fishing notes that shore coalfish often feed within about 30 yards of the sand line, so an accurate short cast beats distance.

For open beaches and rock marks:

Tie a 3-hook flapper with size 2 Aberdeen hooks.
Clip on a release-wire lead.
Bait with crab, mussel, sandeel, lugworm, ragworm or mackerel strip.
Fish the flood, ideally after dark when the water is clear.

For billet in harbours and off piers, fish a light float with the bait just off the bottom, tight to the walls. A 1-up 1-down rig with 12in snoods and size 2 to 4 hooks also works.

On rocky Scottish marks, try 3/4oz to 1.5oz chrome spinners over rough ground. Small coalfish also take mackerel feathers.

If you fish the north-east coast this winter, start with the flapper, crab or mussel, and a rising tide after dark.

How to Catch Coalfish from a Boat

On a busy wreck, shoals of 4lb to 5lb coalfish often beat the bigger fish to the lure, so experienced skippers move on to find the doubles.

Wrecks. Fish a flying collar or Whitby-style rig with a 7ft to 9ft hooklength, lengthened towards 15ft when bites are shy. Use 3in to 10in soft shads or sandeel lures, retrieved steadily from the bottom. Feeding tends to peak in the first two to three hours of the flood and ebb, and falls off at slack water.

Reefs. Fish a hopping rig on braid for bite detection, since mono stretches too much. Drop to the seabed, wind up about 2ft more than the hooklength, then work the tip up and down a couple of feet.

Colour. If pollack keep coming up, switch to orange, lumo green or pink. For bait, use hooks up to about 2/0.

Wreck and reef marks are reached by charter boat, so ask the skipper which rigs and lures are working before you set up.

Legal Size, Fish Care and Eating Coalfish

The UK minimum conservation reference size for saithe (coalfish) is 35cm, per the GOV.UK MCRS guidance updated 3 February 2026. Local byelaws can differ, so check with your IFCA, or the relevant authority in Scotland, Wales or Northern Ireland.

Return small billet quickly. Wet your hands, unhook with forceps, support the fish and keep it off hot rocks and dry decks.

Coalfish has grey, mild flesh, sold as coley, smoked, or in fish fingers and fish cakes, and usually cheaper than cod or haddock. Saithe stocks are assessed by ICES and many fisheries are MSC certified, but ratings vary by area, so check the MCS Good Fish Guide.

Keep the odd legal fish for the table and return the rest.

Frequently asked questions

Is coley the same as coalfish?

Yes. Coley, saithe and coalfish are all one species, Pollachius virens, according to the MSC. Young fish are often called billet or podleys. Do not confuse it with pollack, a close relative with a lateral line that curves over the pectoral fin and a protruding lower jaw.

What is the minimum size for keeping a coalfish?

The UK minimum conservation reference size for coalfish is 35cm, 5cm more than for pollack, under GOV.UK guidance updated 3 February 2026. Local IFCA byelaws can differ, so check the rules for your area before keeping any fish.

Can you catch coalfish in summer?

Yes, but mostly small ones. Billet stay around harbours, piers and estuaries all year. Bigger open-coast shore fish typically arrive from mid to late October and are best through to late March, mainly in the north. Boat anglers find larger coalfish on deep wrecks and reefs.