Richard Benyon MP. Minister for Natural Environment and Fisheries
United Kingdom

Avon Valley Cormorants – Biodiversity in Danger.

Compiled and co-written by Jim Wreglesworth, Trevor Harrop, Hugh Miles, Budgie Price,
Peter Pleydell-Bouverie, Chris Whalley and Peter Orchard.

 Non-native invasive species.

 Population explosion.

 A direct threat to SSSI and SAC protected species.


There has been a significant increase in the numbers of cormorants feeding within the River Avon valley.

Numbers of UK cormorants have been bolstered by an influx of non-native birds from mainland Europe of the subspecies Phalacrocorax carbo sinensis. This began in, and has been increasing since the 1980’s.

The presence of cormorants in such large numbers is a direct threat to precious Avon fish populations and other highly valued native wildlife.

The current licensing system does not provide river managers with an effective legal option for controlling the number, or influencing the behaviour of the Avon cormorant population.

Good habitat management can only do so much to ensure fish survival and recruitment; a more direct method is required to reduce the impact of cormorants on local fish populations and native wildlife.

Cormorant-scaring tactics and fish refuges do not work in a river environment; shooting is the only realistic option.

DEFRA announced in January 2011 that Richard Benyon MP will carry out a review of the current licensing system – now is the time to voice our concerns and get the cormorant included on the “General License”.

Background & Current Situation.

There are two types, or “subspecies”, of cormorant. One is native to the UK, while the other has only arrived from mainland Europe in recent years – first becoming established at UK inland locations during the early 1980’s. Colonies of these birds grew rapidly and by 2005, numbers of breeding pairs increased to 2,096.

“This population is thought to have been founded by continental birds, originating primarily from The Netherlands and Denmark”
(The Status of inland-breeding great Cormorants in England – Newson, Marchant, Ekins & Sellers).

The arrival and increase of the European subspecies is of significant note because it habitually prefers to feed and breed at inland locations, such as lakes, gravel pits and rivers, all of which are features of the Avon valley.

Each pair of cormorants is capable of rearing 1-3 young each summer, and with increasing numbers of European birds remaining in the UK for the breeding season it is no wonder that we are seeing more and more cormorants on our inland waters.

It is estimated that there is now “…a wintering population in Great Britain of around 23,000 birds” (Natural England Technical Information Note TIN041 – second edition, January 2011). This rate of rise in population of cormorants is having a devastating impact on already fragile fish populations.

Historically, numbers of cormorants have been controlled, but like all UK wild birds they are now protected under the Wildlife and Countryside Act 1981. Currently a personal license (issued by DEFRA) is required to legally shoot cormorants.

Such large, uncontrolled numbers of cormorants are a threat to our native wildlife and to the rivers’ important SSSI and SAC designation. There is a growing fear of the impact these invasive birds are having on our native fauna, both in the short and long term.

The direct predation of fish inhabiting the Avon is a concern from a fish conservation perspective. However, the knock-on effects of a river ecosystem lacking in fish is disastrous for other important and much-loved native creatures such as the otter, grebe and kingfisher. Fish are a crucial, yet often over-looked link in the food chain.

There is some speculation as to the actual quantity of fish which a single cormorant typically eats. But undoubtedly the large flocks of cormorants feeding in the Avon valley do consume significant numbers of fish, even based on the most conservative consumption estimates.

“On average, an adult cormorant requires around 400g – 500g (about one pound) of food each day although the weight of fish eaten on a particular day can vary considerably”.
(The Moran Committee – Cormorants the Facts)

Cormorants are superbly adapted to hunt fish, and watching a cormorant feeding in a coastal environment demonstrates that they are able to hunt efficiently in very large bodies of water. To watch that same highly evolved predator hunting in a relatively small chalk stream is comparable to watching a tiger hunting sheep in a barn.

Species such as salmon and bullhead should be protected under the river’s SSSI and SAC designation and, under the Water Framework Directive, good fish populations are considered a key indicator of a healthy and balanced ecosystem. With Avon salmon populations already perilously low, and in steep decline, any further predation of salmon smolt will be catastrophic. In spite of this we do not currently have effective methods or financial support available to manage inland cormorant numbers.

In addition to those fish species supposedly already protected by European law there are other species, such as roach, which have become increasingly scarce. There is huge concern that the large numbers of cormorants feeding in the Avon are having a devastating impact on the remaining fragile populations of some fish species. With numbers of Avon salmon, roach and eels at critically low levels, the continued impact of such high levels of cormorant predation could be irreversible. Since 2005, Environment Agency fish surveys have demonstrated a severe decline and almost disappearance of roach from the Avon’s middle reaches.

“…if fish numbers fall to a very low level, predation by birds could become a factor in the survival of local populations”.
(The Moran Committee – Cormorants the Facts)

Angling supports a huge economic sector within the Avon valley, but at present the people charged with managing that sector (landowners, river-keepers, fishing clubs and rent payers) have no effective, legal way of controlling cormorants or reducing the threat they pose to this precious SSSI.

Good river management and habitat creation, while crucial, can only do so much to maintain fish survival and recruitment. In a lake environment there are various methods which can be used in an attempt to protect fish populations from cormorant predation e.g. artificial refuges. On a river system however it is much more difficult, with shooting being the only effective method.

“For rivers, increasing human disturbance, non-lethal shooting to scare and shooting to kill (either to reinforce scaring or reduce cormorant numbers at the site) appear to be the only options that may be effective.”
(Natural England Technical Information Note TIN041 – second edition, January 2011).

Currently a river-keeper can apply to DEFRA for a personal license to shoot a number of cormorants. Typically though, that number will be restricted to as few as 3 or 4 birds per year!

Given that individual flocks of cormorants are regularly seen during the winter months numbering in excess of 100 birds, with individual flocks of as many as 300 being reported, the small number of birds on the license renders the process of obtaining the license almost pointless. It is however crucial that, until the licensing system has been changed, all relevant bodies should apply for a license so that a strong message is sent to DEFRA that the cormorant problem is worse than ever.

What is needed?

Make no mistake, this is a complex issue. There are many factors both inside and outside of the Avon valley which have influenced the development of the local cormorant population. They all need to be understood and managed.

However, in order for our fragile river to be preserved at a local level the river managers must have the legal right to control cormorant numbers. Funding and support from the government may be needed to assist in this process and should be made available as required.

For there to be a realistic improvement in the situation it is widely felt that cormorants should be included on the “General License”.

“General Licenses reduce bureaucracy by allowing people to carry out activities that affect protected species without the need to apply for a personal licence”

It seems obvious that the Avon cormorant population poses a threat to the sustainability of the Avon SSSI and SAC. This cormorant issue seems to fit perfectly within the General License section “Management of species causing conflict with conservation or human interests”.

It is essential that this problem can be tackled in a legal and efficient way. To include the cormorant on the General License would seem to be the best way of doing so.

Perhaps not all landowners within the Avon valley will want to adopt the same management techniques, but it is crucial that they should have both the legal right and financial support to do so if they wish.

DEFRA announced in January 2011 that Richard Benyon MP will carry out a review of the cormorant licensing regime. We would like to urge everybody to take this opportunity to voice their concerns in writing to:

Richard Benyon MP
Minister for Natural Environment and Fisheries
Department for Environment, Food & Rural Affairs
Nobel House
17 Smith Square
London SW1P 3JR

The current Cormorant licensing regime is woefully inadequate as it stands. Therefore, we the undersigned call upon the Minister for Natural Environment and Fisheries to change the licensing law and include the Cormorant on the ‘General License’, allowing the legal control of Cormorant numbers where they pose a threat to fish populations.

In so doing, this will allow the vital link in the food chain to be maintained, and the protection of not only endangered fish species, but also species such as Kingfishers, Grebes and Otters.

We should have the right to protect our environment, but the current law does not allow this.

The Cormorant problem is NOT Avon specific, but affects rivers, lakes, canals and reservoirs all over the country.

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The Biodiversity in Danger - Review Cormorant licensing regime petition to Richard Benyon MP. Minister for Natural Environment and Fisheries was written by Trevor Harrop, Budgie Price, J.Wreglesworth, Hugh Miles, P.Pleydell-Bouverie, C.Whalley & P.Orchard and is in the category Environment at GoPetition.