Wednesday, December 12, 2007

Trout Decide to Make a Break for It






Trout leap to freedom in incredible escape from pond through eight-inch pipe

By NICK McDERMOTT - More by this author » Last updated at 08:19am on 12th December 2007

Down on the fish farm, workers could not understand why the number of brown trout had suddenly taken a dive.

But close observation revealed the reason - an aquatic version of the Great Escape.

The resourceful fish are leaping 3ft out of the water and into an eight-inch pipe which brings fresh water into the farm near Alresford, Hampshire.

Following their instincts the trout, cousins of the Atlantic salmon, then swim against the flow for 30ft before finding freedom at the other end as they plop into a tributary of the River Itchen.

Simon Johnson, director of the Wild Trout Trust, said: "Brown trout do have migratory tendencies and swim upstream, especially in November and December.

"The water coming down from the pipe is oxygenating the pond and this could be kicking in their natural instincts.

"They might well think it is a waterfall and are trying to head up it to find a place to spawn."

The Escape Committee were caught in the act by wildlife photographer Dennis Bright, 59.

A farm worker said: "It is remarkable how they manage to jump so high and through such a small pipe.

"We run a low-intensity farm and like to let nature thrive so we don't net our ponds. As a result we lose up to 40 per cent of our stock to predators every year.

"To see us losing more fish through pipes that are designed to help them is a bit of a blow. But to be honest, if I were them I would be trying to escape too. Good luck to 'em."

Wildlife photographer Dennis Bright, 59, captured the amazing aerobatic fish earlier this week.

He said: "It was an incredible sight.

"Swimming against the current is instinctive for trout as they head up stream to spawn but they are doing a remarkable job getting through that pipe.

"They are jumping for freedom in large volumes but sadly I think their fate will be less than happy - there are otter, herons and many other predators feeding from the stream.

"I imagine the trout are quite stressed in the ponds because it is a free-for-all for predators.

"When birds come along the fish don't stand a chance."

The Brown Trout (Salmo trutta) belongs to the Salmonidae family which includes the Atlantic salmon.

It is a medium sized fish, growing to 20 kg or more in some localities although in many smaller rivers a mature weight of 1 kg (2 lb) or less is common.

They prefer cold (15.5-18.3 C), well-oxygenated upland waters, especially large streams in mountainous areas.

Their diet includes invertebrates from the streambed, small fish, frogs, and insects flying near the water's surface.

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