President Bush is having a tough 2008 but one group in Europe thinks the USA is the model of conservation when it comes to Cormorant management.

The Great Cormorant (Phalacrocorax carbo) is regarded by fishermen in Europe as the "black plague" that steal their fish and eat them in front of their eyes, while conservationists celebrate the increase in the number of cormorants as proof of the fact that the conservation measures of recent decades have been successful.

The Cormorant breeds in the North and the Baltic Sea area but winters in the proximity of the Mediterranean - therefore it is an issue for the EU, not local government. But the fishermen impacted do not want other European countries determining their fate. And most of the countries agree that whether the cormorant population in Europe is half a million or one and a half million, depending on who provides the data, the focus of conservation work should be on endangered species.

The approaches of other countries are individual as well. The Netherlands is completely opposed to culling while France culls 40,000 cormorants per year. "With the involvement of 25 member states it is indeed difficult to find a regulation with which all states are satisfied. If only one member state disagrees, then the plan will not materialise", says Vivien Behrens of the Helmholtz Centre for Environmental Research (UFZ).

She and colleagues conducted interviews with decision-makers on this subject and investigated why a common European cormorant management strategy is so difficult. From her point of view past attempts have failed, because Europe lacks the bureaucratic agency to mandate a solution: "In Europe it is clearly an institutional problem: Who is responsible? Is it the conservation agencies, the fishery authorities or other actors? There are so many different levels involved from the regional and national to the international level, and yet there is no one place for all of these threads to intertwine, where one can say: We are now going to develop an action plan that we can use to regulate the problem."

Officially, the ORNIS committee would be the responsible body, but they have categorised the problem as not urgent. In the meetings, in which the approach and the results of the research work were presented, there was always at least a representative of one country that did not consider an action plan to be necessary.

The Convention on Migratory Species (CMS) clearly stated the fact that the cormorant population is sufficiently stable at the moment and therefore does not have to be regulated, as this convention concentrates first and foremost on highly endangered species.

The researchers have come up with a five-step action plan.

First - obtain accurate data on cormorant population, as the estimated numbers are varying according to the respective interests.

Second - an EU institution would have to be set up which would be responsible for the application of a common management strategy. A difficult process, requiring mutual understanding, as all countries would have to give up their decision-making autonomy.

The fact that a trans-national cormorant management policy is possible can be illustrated by the example of the USA where a central authority is responsible, namely the U.S. Fish and Wildlife Service in the Ministry of the Interior. The problem in North America is comparable with Europe: Since the 1970's, populations of the Double-crested Cormorants of North America (Phalacrocorax auritus) have been increasing. Breeding and wintering areas are distributed over the entire continent and therefore over different Federal States.

After an intensive consultation process, a management plan with over 200 pages was compiled in 2003, which is now being applied religiously. This plan is structured with alternatives, which are introduced progressively and only implemented if the previous stage remained unsuccessful:

1. no intervention
2. scaring birds (without shooting)
3. limiting local damage at commercial fish ponds
4. strictly monitored reduction of resources
5. reduction of regional populations
6. opening up national hunting as a last alternative.

In this way the cormorant population in North America is to be reduced by approximately 160,000 birds, which according to estimations from the U.S. Fish and Wildlife Service will not lead to any apparent negative consequences for the population.

Apart from the institutional shortcomings in Europe, there is another reason why past attempts to regulate cormorant populations have failed. The structure of the cormorant population makes their regulation difficult: "Some of the birds are not breeding in spite of being sexually mature, because they are waiting for the chance to occupy a free nesting spot to be able to provide for their young", explains Sten Zeibig from the UFZ, who is currently working on a model of the cormorant population in Europe. "These so-called floaters provide a kind of natural buffer that protects the population from severe losses after disasters. If the breeding birds are killed, then the 'floaters' will take their place until this buffer is depleted, and the population breaks down to the point of being threatened with extinction."

In his model, Zeibig ran different scenarios and came to the following result: The most effective and also most ecologically compatible option was to reduce the capacity of the environment for breeding birds in that for example dead trees used for nesting are felled, and additionally preventing new nests from being built. Likewise smaller and medium-sized fish ponds can be covered with nets.

"With this option one would kill two birds with one stone: The losses of fishermen would be reduced and at the same time the cormorant population structure protected, whereby the crucial buffer would still remain intact."

By comparison, oiling the eggs - mostly practiced in Denmark - come off less well in the model, as the consequence was a high fluctuation in the population, increasing the risk for the cormorant population. With his model, the DBU (Deutsche Bundesstiftung Umwelt) research fellow Zeibig was able to set up some first rules of thumb for an ecologically compatible regulation of the cormorant population.

He recommends: maintaining the buffer structure of the population, to intervene only indirect by reducing capacities, and if that should not be possible, through careful intervention by shooting, in order to keep the structure of the population.

You can read more about biological invasions and other issues concerning biodiversity in a special edition of the UFZ newsletter for the 9th Meeting of the Conference of the Parties to the Convention on Biological Diversity (COP9), that was from 19 to 30 May in Bonn.