Having a wild, Catch & Release fishery means that management of the environment is crucial in sustaining our sport. Predation of fish stocks is a natural event, and forms part of the calculation of survival odds for the breeding population. Sometimes however, over-predation can occur and cause potential long-term issues for the river.
Anglers should be aware of the predators likely to cause issues if they take up residence on the river in excessive numbers. Be vigilant, and keep a mental note of these less welcome visitors; if you think you are seeing an increase in their numbers, report it to the club.
A male Goosander - feared by fisheries, but is their reputation deserved?
The Ewenny supports some wonderfully diverse birdlife, but occasionally it attracts some whose presence is less welcome. Most anglers are familiar with Herons and the more troublesome Cormorants (though the latter rarely visits small rivers), but of greater concern are Sawbills. These fish-eaters, though not common, are voracious predators of small fish.
There are two principal species, the Goosander and the slightly smaller Merganser. They are relatively common in Scotland and the north-west of England, but though colonies in the rest of the UK do exist they are, so far, not wide-spread. They are more likely to be spotted as visitors during the winter months, as they migrate south to escape the ice. Isolated and visiting birds are unlikely to cause much, if any, impact as they simply form part of the natural predation pattern in the river. The arrival of resident breeding pairs though would potentially constitute more of a threat.
Like all wild birds, Goosanders and Mergansers are protected. Scaring is not likely to be greatly effective, so a positive approach to fish stock protection is more appropriate. By providing ample cover for young fish to shelter in, we make the birds' principal food source more difficult to catch! Fortunately, PADAC's work to enhance the river already includes measures to protect juvenile fish so providing excellent habitat to keep the preditor/prey balance in check.
To help you keep an eye on these visitors, take a look at the photos above and to the left so you can identify them.
To get the facts on Sawbills and how they effect fisheries, click on the link below for the Environment Agency publication:
A Female Goosander - note the red-brown head
A male Merganser - a crested black head and white collar make it easy to spot.
A female Merganser - crested Russet head
The Ewenny does have a small resident population of Mink. They are frequently seen sidling along the river banks by Anglers, and display remarkable boldness and curiosity at times.
A handsome and bold dog mink watches an angler from the opposite bank
Mink (or American Mink as they are properly called) are an invasive species, introduced to the UK in the 1950's for fur farming. Descended from animals that escaped captivity, wild mink have been highly succesful in Britain and have spread across most of the country. They are voracious and indiscriminate hunters, taking small mammals, birds, eggs and fish where the opportunities arise. Whilst not as adept in water as the more specialised Otter, Mink have been known to cause damage to fisheries, though in rivers, their impact is less keenly felt than in lakes and ponds. Their numbers do have to be kept in check through trapping and other methods. Unchecked, they could cause significant damage to the local ecology. It is advisable to report mink sightings to the club so they can be monitored.
Otters present a different case. As an indiginous species, and a rare one, it could be considered something of a privilage to have one resident on the river; only a waterway that is clean, healthy and with abdudant biodiversity could support a natural preditor like the Otter. Reports have been made that an Otter has taken up residence on the river, but sightings have been rare.
Further information on American Mink can be found here: