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No.3
Migrating Salmon

The spectacle of the Atlantic Salmon leaping out of the water as it returns to its spawning grounds is one of the most dynamic migration displays to be seen anywhere in the animal kingdom.

The Atlantic Salmon (Salmo Salar) is a migratory fish which is 'anadromous' - this means that it migrates from the sea into fresh waters to spawn. There is just one species of Atlantic Salmon compared with the six species of Pacific Salmon.

During their journey the salmon undergo remarkable changes as they head for their spawning grounds. When the fish first enter the river system from the sea they’re a silvery colour. Then the males go through many radical physical and physiological changes. They stop feeding, their flanks change colour and they take on all sorts of hues – reds and greens – known locally as "taking on the tartan". Males also develop a pronounced jaw which lengthens to form a hook known as a kype, and their sexual organs develop.

The fish are driven by their hormones – it’s said that they can 'smell' the right river. When they arrive at their destination, the Salmon start leaping. They generally reach a height of around four feet, but this depends on the height of the water at the time.ÌýThe highest Salmon leap in the UK is thought to be 11-12 feet. The Salmon sometimes dive down deep to get a bit of momentum for their leap so they can power their way upstream with maximum energy. They also have to rest and recuperate between a series of leaps.

Photo credits

The Atlantic Salmon images are copyright and courtesy of Gilbert van Ryckevorsel and David Hay.

Web links

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Photo gallery

Watch and Listen

Join presenter Mike Dilger as he watches spectacular leaping Salmon on the River Almond near Perth in Scotland:

playing audio/video

Tips

Tips for viewing this species:

• The peak times for salmon leaps are between mid September and November with October being the prime month.Ìý Check for weather conditions and updates on the t website.
• Salmon are most active after heavy rain especially when this follows a dry spell. At this point the adult salmon head upstream to spawn and will jump repeatedly at obstacles such as waterfalls. Watch the fish as they come flying past.
• To measure the height of a salmon leap, put someone or something of known height at a similar distance to where the Salmon is leaping – the same distance as the fish is from you. For example, dangle a piece of string of known length over the side of the waterfall in the place where the Salmon are expected to leap – take a photo and compare distances.
• A good place to watch the salmon leap is Buchanty Spout on the River Almond, which is part of the Tay system in Scotland. In the late autumn the Salmon fight their way up through the gushing torrents, determinedly pressing on to reach their spawning grounds upstream. You can get closer to leaping salmon here than at any other site in the area. However, caution is required on the rocks near to the waterfall.
• The Tay itself is a very productive salmon river in its own right. Almondmouth is a good spot because of its location on the high tide limit which means that every salmon entering the Tay must pass through it. Head for Buchanty Spout, a natural corridor that channels the salmon close to the hundreds of onlookers who make the journey to see them each year. Buchanty Spout is where the River Almond crosses the Highland boundary fault, which divides the highlands from the lowlands and is the biggest obstacle these fish will encounter as they follow the urge to spawn.
• Other good salmon sites are Philiphaugh Cauld (River Tweed), the Falls of Shin, the River Spey (Dalwhinnie), Linn of Tummel (Pitlochry), the Orrin Falls (Ross-shire) and the Falls of Feugh (River Dee system).

Habitat

The Atlantic Salmon is a fish of both sea and freshwater. Once the Salmon reaches maturity, it heads out to sea on its journey to its spawning grounds. Returning adults tend to stick together in groups or 'tags'.ÌýWhen out at sea the fish spend most of their time in the top 5-10 metres of the water in sunlight, but at night they leave the surface and swim deeper to feed on crustaceans and young fish.Ìý

By the time the salmon get to their spawning grounds they’ve already come a long way – they will have spent several years out at sea fattening up, getting ready for an amazing journey that brings them right back to the river in which they were born. Many Scottish fish will have fed in Greenland and around the Faroe Isles.ÌýHow quickly they move to their destination is dependant on weather conditions and tides.

Once they reach their chosen area, the salmon wait in the lower reaches of the waterway system for enough water to enter their chosen river after heavy rain so they can get their bodies over the various obstacles in the river. Then it's time for the leap to begin.

Some of the best places to watch salmon leaping are the River Tay, the River Tweed and the River Dee.