Saithe

The saithe (Pollachius virens), also called coalfish, is a mid-to-large Gadidae species found throughout the North Atlantic, from the Barents Sea and Iceland south to the Bay of Biscay, and in cold coastal waters of eastern North America. Named for its dark, coal-like coloration, saithe are more streamlined and pelagic in habit than bottom-dwelling cod, often forming large schools in open midwater along rocky coastlines. It is closely related to pollock (Pollachius pollachius) but tends toward darker coloring and slightly different fin proportions. Saithe support extensive coastal and offshore populations across the North Atlantic and play a significant role as a mid-water predator linking smaller schooling fish to larger marine predators.

Saithe are streamlined, torpedo-shaped fish with dark coloring that sets them apart from paler Gadidae relatives.

• Body: elongated, fusiform, built for sustained swimming
• Color: dark greenish-black to bronze-grey above, silvery below, with a faint pale lateral line
• Fins: three dorsal fins, two anal fins, small chin barbel (often minute or absent in adults)
• Jaw: lower jaw slightly projecting
• Size: commonly 60-100 cm

Saithe are distinguished from pollock by their straighter, less curved lateral line and more uniformly dark coloration, and from cod by their much smaller or absent chin barbel and more slender, streamlined build.

Saithe range widely across the North Atlantic, from the Barents Sea, Iceland, and Norway south to the Bay of Biscay in the east, and from Labrador to Cape Cod in the west. Juveniles favor shallow, rocky inshore waters and tide pools close to shore, gradually moving into deeper offshore waters as they mature. Adults typically occupy midwater zones over rocky and mixed seabeds at depths from near the surface down to around 300 m. Saithe tolerate cool temperate waters and are commonly associated with rocky coastlines, fjords, and offshore banks, often schooling in open water well above the seabed rather than remaining strictly demersal.

Saithe are active, fast-swimming schooling fish that spend much of their time in open midwater rather than hugging the seabed like true cod. Juveniles shoal in shallow rocky pools and are highly visible near the surface, while adults form large, cohesive schools that hunt small fish such as sandeels, sprat, and herring, along with krill and other crustaceans. Spawning occurs offshore in deep water during winter and early spring, with females producing large numbers of buoyant pelagic eggs that drift and hatch in open water. As agile midwater predators, saithe help regulate populations of smaller schooling fish and serve as prey for seabirds, seals, and larger predatory fish across North Atlantic coastal ecosystems.