Fordhead Farm: Fish

Species of Fish at Fordhead

The following descriptions relate to the various species of fish that inhabit the Fordhead sections of the River Forth and the Boquhan burn. (Note: Illustrations not to scale)

The following Seasons are in effect for game fish

Brown Trout: 15th March - 6th October

Sea Trout and Salmon: The season varies from river to river, the dates for the River Forth are - 1st February - 31st October

Fishing for these species out with these dates is illegal in Scotland.

Brown Trout

There are an abundance of Brown Trout in the Forth and also in the Boquhan Burn which joins the Forth just west of the Ford.

The burn has ideal pools for trout and also has a gravel bottom that suits them.

The Fords are also ideal for trout due to the aquatic vegetation (which provides cover) and the stones and gravel that make up the majority of the riverbed.

Brown Trout spawn in the winter months (from January to March). A spawning female is usually accompanied by more than one male. After the eggs are fertilised, the female covers them with sand and gravel. The newly hatched fry have a yolk sac as a source of food for the first few days of life. When his has been consumed, they catch small insect larvae and crustaceans. As the trout grow, they begin to feed on larger insects which have fallen onto the water.

Feeding fish suck the insects from the surface of the water creating the characteristic rings (best seen on a calm evening with little wind). This tell tale sign of a feeding fish is called a 'rise'. Larger fish also feed on smaller ones (including small trout).

The Brown Trout Sal mo trutta fario

Juvenile
Male
Female

In the warm summer months and during periods of low water, patient observation will be rewarded with the sight of trout leaping out of the water. This can be seen in the deeper pools as well as the faster flowing shallows and is most common in young fish - leaping completely into the air, often in quick succession.

Sea Trout

The Sea Trout Salmo trutta trutta

Sea Trout inhabit the Forth and they pass the Fordhead stretch as they make their way upstream to spawn. They also pass again on their way back to the sea.

Sea Trout are magnificent fish and a fully grown specimen can reach a length of over 1m and a weight in excess of 30kg.

Spawning takes place from December to March in gravel beds (or 'redds') in the upper reaches of the river. Like the Trout and the Salmon, the Sea Trout covers her fertilised eggs with sand and gravel to protect them from predators.

When the young fish reach the size of 10-20 cm in length, they migrate sea-wards. They stay in the ocean until they mature, migrating back to the same river they were spawned in. The migration into the rivers normally begins in June or July but can take place a little later in the autumn months. On still evenings, Sea Trout can be seen leaping out of the water - even although there is no natural obstacle to conquer. Another sign of fish on the move is the bow-wave they sometimes make as they swim close to the surface.

Experiments have shown that if a Sea Trout is unable to escape from fresh water to the sea, it becomes a Brown Trout or Lake Trout. If young Brown Trout or Lake Trout are introduced to the sea, they become typical Sea Trout and at spawning time migrate to fresh water. The three are thus not separate species, but are at most subspecies.

Atlantic Salmon

Salmon are still numerous in the Forth, despite the drastic impact that commercial fishing has made on their population in general.

The life cycle of the Salmon is similar to that of the Sea Trout in that it lives part of its life in fresh water and part of its life in sea water, returning on maturity to spawn in the same river as it was spawned in.

Due to the arduous journey a Salmon makes to reach the spawning grounds, the exhausted fish (called a 'Kelt') normally dies after it spawns, only a very few fish survive to spawn a second time.

The spawning grounds are beds of sand and gravel in the upper reaches of the river (further downstream than the Sea Trout however). As many as 30,000 fertilised eggs are deposited in a 'Redd' (a furrow in the gravel riverbed), then covered over to protect them from predators.

The eggs hatch in April or May and the the young Salmon are only 2cm long at this stage. They are sustained for the next 40 days by the contents of their large yolk sac. When this is exhausted, they live on small planktonic crustaceans, insect larvae and (later), small fish.

The young Salmon remain in fresh water for 2-5 years and are known as 'Parr' during this time.

Eventually they transform into the silvery 'Smolt'' and set off on their long journey down to the sea.

The Atlantic Salmon Salmo salar

Salmon 'Parr'

Salmon 'Smolt'

Adult

Migrating MaleMigrating Female

Salmon remain in the ocean for 1 - 4 years. They live on fish during this time (herring, etc) and rapidly gain weight and size. Exceptional specimens of mature Salmon reach lengths of 1.5m and weigh over 30kg. Their flesh contains a large amount of fat and turns 'salmon' pink. This trait is seen in the returning fish, especially in the males.

Like the Sea trout, Salmon will leap out of the water, even on featureless slow-moving parts of the river. If you are fortunate to be looking at the right spot, you will be rewarded with the sight of a fully grown fish leaping clear of the water - returning in a huge splash as it broadsides into the surface of the water.

When fully grown and matured, the Salmon migrate back up the rivers in which they were spawned, guided by the unique chemistry of the water. Like the Sea trout, they overcome daunting obstacles on their journey upstream (weirs, dams, rapids, waterfalls, etc). Finally, in the colder upper reaches, the spawning process begins again and a new generation of Salmon will emerge to replace the previous one.

Perch

The Perch Perca fluviatilis

The perch is a shoaling fish that lives in the slower, deeper areas of the Forth.

It has a high-backed, flat-sided body with a spiny first dorsal fin and spikes on each gill cover. These spines and spikes can give a serious puncture wound to the unwary, so handle Perch with care.

The colouring of the Perch is striking, with a blackish green back and lighter greenish yellow sides crossed by up to 9 dark bands, often extending down to near the white belly. The dorsal fin is greenish gray with a characteristic dark spot to the rear. The second dorsal is often translucent greenish yellow as are the pectoral fins. The pair of ventral fins are often reddish orange, as is the anal fin and the caudal fin is often closer to red.

Perch grow to around 30-50cm and weigh around 1-2kg. They spawn in April and May and this often continues into June. The eggs are joined together in ribbon-like strings 1-2 am long and 1-2 cm wide. These eggs are laid on stones, submerged branches and roots or aquatic plants in shallow water, generally at night.

The parent fish do not look after the eggs or the fry, which usually hatch in 14-17 days. The newly hatched young fish are 3-6mm long with an egg-shaped yolk sac containing a large drop of oil which enables them to float in the water. The fry at first live on small planktonic organisms, and later on, the fry of other species of fish.

Living mainly on fish, the young Perch will often form large shoals and sometimes drive prey towards one another. Young fish hunt in shallow water, older fish prefer deeper, slow-moving water and solitude.

Pike

The Pike is a superbly designed killing machine. The streamlined body is practically the same width along its entire length. The head is very long and has tapering jaws with a very wide gaping flat-topped snout full of teeth.

There are actually no teeth on the upper jaw, but this is more than made up for by the profusion of long curved teeth on the lower jaw. There are also teeth on the palate, the intermaxillary bones, the vomer and hyoid bones and even the gill arches.

The Pike Esox lucius

The dorsal, caudal and anal fins all reside at the rear of the body in close proximity. It is this arrangement that allows the Pike to pounce on its prey in a split second of deadly thrust. Pike live almost exclusively on fish and attain a length of up to 1.5m and can weigh over 20kg. Exceptional specimens have reached weights of 35kg.

The colour of the Pike varies with the environmental conditions. Young fish are usually light green, brownish or silvery. The dark spots on their sides often merge to form cross-bands. Adult Pike have a dark green back, greenish blue (and often yellow spotted) sides and a white belly. Their paired fins are light coloured and their unpaired fins are marked with dark cross-stripes: reddish or russet stripes can sometimes be seen between the rays of the anal and caudal fin.

Pike spawn early in the spring, in March and April, when they assemble in overgrown shallows. The tiny eggs are stuck to aquatic plants or grasses and the young are hatched in 12-15 days.

Eels

The European Eel Anguilla anguilla

Eels can be caught in the Forth almost all year round. They are bottom feeders and like the sandy, muddy bed of the slow moving sections of the river.

The eel has a long serpentine body that is almost round in cross section. The dorsal and anal fins are continuous with the caudal fin. The only paired fins are the pectorals - behind the head.

The fish has a dark gray/green back, lighter sides and a white belly. After it reaches sexual maturity, the sides and the belly change to a silvery gray. Male eels are never more than 50cm long, but females can measure up to 150cm and can weigh over 6kg.

Eels spawn in only one place - The Sargasso Sea - near to the Gulf of Mexico in the Atlantic Ocean. They will move downstream on dark moonless nights and begin their 1 and a half year trek to the spawning grounds. They spawn in deep water, then die.

The transparent little larvae, which look like willow leaves, drift with the Gulf Stream towards Europe, reaching it in about 3 years. Between October and April, in river mouths, they develop into elvers measuring about 6 cm in length. The elvers migrate upstream in massive numbers. They overcome the most diverse obstacles - rock faces, waterfalls and even dry land. When they finally find a place to settle, deep inland, they remain there for 13-16 years. In winter, they spend their time in the mud at the bottom of the rivers.