- Scientific name: Trachurus trachurus
- Also known as: Horse Mackerel, Atlantic Horse Mackerel, Common Scad
- Size: Up to 18ins and 3lb. UK shore caught usually under 12ins and 1lb.
- UK minimum size: 25cm/10inches
- UK shore caught record: 3lb
- IUCN Status:
- Global: VU (Vulnerable)
- Europe: LC (Least Concern)
- IUCN Status:
- Distribution: Found throughout the UK in summer months but more common around the south and west coasts, with a separate population migrating from Scandinavia to the coast of Scotland in summer.
- Feeds on: Mostly feeds by hunting small fish, sandeels and squid, although will take most edible creatures it comes across including crustaceans.
- Description: Streamlined silvery body, with green/grey back. Two dorsal fins, first of which is tall and spined, the second is longer and flatter, as is the anal fin. The tail is deeply forked. The unusual scaly lateral line runs all the way from the tail to the gills and curves upwards over the large pectoral fin. Large eyes and a black mark is present on the gill cover.
- Additional notes: Not to be confused with Shad.
Scad is a shoaling species which is found mostly to the south and west of the British Isles, with their range extending to northern European waters, off the north coast of Africa and throughout the Mediterranean and Black Sea. Despite the name they are not closely related to Atlantic mackerel which is so common around much of the UK, and are instead more closely related to the jack mackerel species found in the Pacific. The alternative name of horse mackerel comes from the untrue belief that other small species of fish would ride on the back of scad as they swam through the sea.
Scad can be found at all water levels. They will hunt at or near the surface for small fish and will also scavenge for sources of food on the seabed. At certain times it is thought that crustaceans can make up a large proportion of their diet. Smaller scad can filter feed on plankton, but some reports state that scad may retain this ability throughout their life. Scad inhabits fairly deep water for most of the year, come into shallower water – and within the range of shore anglers – in the warm summer months. Scad are believed to be at their most active when the sun begins to set, spending daylight hours nearer the seabed. The vast majority of scad caught by UK sea anglers are caught on feathers, daylights or other lures. Although scad can reach eighteen inches in length and the UK shore caught record is three pounds they are usually much smaller than this coming in at ten inches or so and under a pound.
Scad is a commercial fish which can be fried or baked. It is also used in frozen food products. Most of the scad caught in UK waters is exported abroad to continental Europe where scad is much more popular as a food fish. Scad is vastly important around Africa where it forms part of the staple diet for millions of people.
Stocks of scad are thought to be relatively healthy in European waters with the IUCN (International Union for the Conservation of Nature) classing this species as one of Least Concern with a stable population trend. However, on a global basis, they class scad as Vulnerable with a declining population trend with “fishing and harvesting” classed as the major threat to this species.