Smelt are a major food source for fish-eating birds and other fish such as trout and sea bass.
Smelt and our canals
The smelt is a marine fish but enters freshwater in the spring to spawn. They shoal in large numbers and are a major food source for fish-eating birds and other fish such as trout and sea bass. They feed primarily on small crustaceans and shrimps, as well as small fish and fry.
How to identify a smelt
Smelt are a relatively small, silver fish. Because they're a distant relation of the salmonid family they have an adipose fin. They have a very short lateral line extending 8 to 10 scales from the gill cover. Over the rest of the body there is no lateral line, but the smelt has a scale count of 59-70.
The smelt's lower jaw projects beyond the upper jaw, and the mouth is lined with rows of many teeth. A cucumber-like smell is characteristic.
Lifecycle of a smelt
When they enter freshwater (typically between February and April), they shed their eggs on sandy river bottoms, with many of the adults dying after spawning.
Hatching occurs at around 3-5 weeks, after which the larvae feed on planktonic organisms.
Where to find smelt
Due to dwindling numbers, smelt aren't widespread across UK canals and rivers.
Historically, during spawning season, they were abundant in the River Thames, and you may still catch a sighting there. Other places to visit are the likes of Diglis Fish Pass, where restoration efforts are actively underway.
Threats to smelt
Smelt are considered a rare and protected species. There are a number of designations which describe their status:
- Listed on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species
- UK Biodiversity Action Plan Priority Species
- Species of principle importance for the purpose of conserving of biodiversity under the Natural Environment and Rural Communities Act 2006
How to catch a smelt
Small hooks (sizes 4-10) and light tackle will increase your chances of catching a smelt. You can also try feather rigs or small lures like mackerel feathers or daylights.
Smelt are attracted to light, so fishing at night can be beneficial.
