Species Action Plans for the conservation of seabirds in the Mediterranean Sea : Audouin ’ s gull , Balearic shearwater and Mediterranean shag *

BirdLife International has so far developed Action Plans for 37 bird species. The plans, although not legally binding, have been approved by the Ornis Committee (EU DG Environment) and most of them have also been endorsed by the Standing Committee of the Bern Convention. Three of the species covered by the SAPs are Mediterranean seabirds: Audouin’s gull (Larus audouinii), Balearic shearwater (Puffinus mauretanicus) and Mediterranean shag (Phalacrocorax aristotelis desmarestii). The documents, which have been produced through a participatory process involving tens of experts across the range of the taxa, provide information on the biology, ecology and threats, but the most important feature is the list of specific objectives and actions which are ranked according to their priority and urgency. Alongside actions addressing species-specific conservation needs, such as site protection and management, a number of activities aimed at the conservation of these species are common and refer to wide policies such as land-use planning, fishery, tourist development and pollution control. The documents represent the most up-to-date and scientifically-based source of information for planning and implementing conservation activities across the Mediterranean, to be implemented by both governmental and non governmental organisations.


INTRODUCTION: THE CONSERVATION STRATEGY OF BIRDLIFE INTERNATIONAL
BirdLife International Strategy is based on 4 pillars: species, sites, habitat and people.
The 'Species' pillar has been developed through the identification of the priority species at a global level (Collar et al., 1994, BirdLife International, 2000), and at a European level (Tucker and Heath, 1994).For all priority species in Europe (SPEC 1 see below) Species Action Plans have been produced.The 'Site' work has led to the identification of 3,619 IBA in Europe (Heath and Evans, 2000) and it is currently under development in Africa (with 4 national inventories already produced), Asia and the Americas.'Habitat' work covers a wide range of activities from actions upon the EU policies (Agriculture, Rural development, Forestry, etc.) to activities at a national level or demonstration projects based on conservation strategies, as in the publication "Habitat for birds in Europe" (Tucker and Evans, 1997).'People', our last but not least pillar, includes communication, awareness and development of the partnership, which currently covers more than 100 countries or territories world-wide.
The four pillars are of course tightly connected and the conservation of congregatory species necessarily involves the conservation of key sites, while dispersed species are better conserved by a habitatoriented approach.Often the two go together since many species can fall into both categories at different times of the year.This is typically the case of seabirds, which are concentrated during breeding but are less so outside breeding time and sites.

THE SPECIES PROGRAMME
Following the identification of the globally threatened species, a survey of the conservation status of 514 European species led to the identification of 278 Species of European Conservation Concern (SPEC), which have been ranked in 4 classes (Tucker and Heath, 1994).
For 23 globally threatened species (SPEC 1), BirdLife International has developed Species Action Plans which have been approved by the Ornis Committee (EU DG Environment) and endorsed by the Bern Convention Standing Committee and by the Bonn Convention and published by the Council of Europe (Heredia et al., 1996).Subsequently 24 further Species Action Plans or Management State-ments have been produced to cover the whole list of species (SPEC 2 and 3) and subspecies which have been identified by the Ornis Committee as priority for funding under the LIFE Nature instrument.
Three of the species covered by the SAPs are Mediterranean seabirds: Audouin's gull (Larus audouinii) [SPEC 1], Balearic shearwater (Puffinus mauretanicus) and Mediterranean shag (Phalacrocorax aristotelis desmarestii).Each action plan was based on the inputs from a workshop with the participation of experts from the European range states and 2-3 drafts were circulated to a wide audience from the research and conservation community.
THE ROLE OF THE SAPS 1. Action Plans provide a framework for action for governments and national governmental agencies, BirdLife partners, other NGOs and scientists.
2. Action Plans, endorsed through intergovernmental agreements, provide an official basis for actions.
3. Action Plans are a reference for fundraising.The plans are intended as tools to identify priority measures for conservation action to halt and restore the populations of the most endangered bird species in Europe, and should assist EU member states in fulfilling their obligations under the Birds Directive.

STRUCTURE OF THE ACTION PLANS
Each plan consists of three main sections.Part 1 deals with background information about status, ecology, threats and current conservation measures.Threats have been rated according to the following categories: -Critical, a factor that could lead to the extinction of the species or sub-species in 20 years or less.
-High, a factor that could lead to a decline of more than 20% of the population in 20 years or less.
-Medium, a factor that could lead to a decline of less than 20% of the population in 20 years or less.
-Low, a factor that is only likely to affect the species or sub-species at a local level.
-Unknown, a factor that is likely to affect the species or sub-species but it is unknown to what extent.
Part 2 includes the aims and generic objectives of the plan.The objectives are grouped under the fol-lowing headings: -Policy and legislation -Species and habitat protection -Monitoring and research -Public awareness.
Each objective is broken down into a series of actions followed by a brief description.These actions are generic and do not make reference to any particular country or geographical region except in special cases.Each action is given a priority rating and a time-scale in which it ought to be carried out using the following categories: -Essential, an action that is needed to prevent a large decline in the population which could lead to the species or sub-species extinction -High, an action that is needed to prevent a decline of more than 20% of the population in 20 years or less -Medium, an action that is needed to prevent a decline of less than 20% of the population in 20 years or less -Low, an action that is needed to prevent local population declines or that is likely to have only a small impact on the population across the range Time-scale: -Immediate, completed within the next year -Short, completed within the next 1-3 years -Medium, completed within the next 1-5 years -Long, completed within the next 1-10 years -Ongoing, an action that is currently being implemented and should continue -Completed, an action that was completed during preparation of the AP Priority actions for most countries within the species range, cross-referenced to the numbered objectives, are listed in an annex to each plan to act as a guide for the preparation of national action plans.

Threats and limiting factors
Main threats and limiting factors identified in the accion plans are summarised in Table 1.Although there are differences in the biology and distribution of these three species, a number of threats are common.Houses, hotels and marinas for tourism are spreading in many areas occupied by the species and can destroy the habitat as well as increase disturbance during the breeding season.For the Balearic shearwater historical and paleontological records suggest that the species was breeding in sites that have been abandoned and possibly the lack of breeding sites is a limiting factor.Food availability is considered a major cause of population fluctuations and mobility of seabirds (Hunt, 1972;Springer et al., 1986).The increase in numbers at the Audouin's gull colony in the Ebro delta is apparently linked to the exploitation of fish waste dumped from boats fishing nearby (Beaubrun, 1983;Oro and Martínez-Villalta, 1994).The industrial use of fish waste to produce animal food, as occurs in other areas of the Mediterranean, could pose a great and immediate threat to the maintenance of the colony at the Ebro delta, which relies largely on this food resource.Data about accidental capture of seabirds in long lines and fishing nets is scarce.In the Balearic Islands the accidental bycatch seems to affect Puffinus less than Calonectris.Some fishing methods such as gill nets and fish traps, particularly when located permanently close to the sea shore, are responsible for killing significant numbers of Mediterranean shags, as has been reported in SPECIES ACTION PLANS FOR MEDITERRANEAN SEABIRDS 49 Balearic Islands (Aguilar, 1991).Interaction with the yellow-legged gull (Larus cachinnans) has been recognised as a limiting factor for Audouin's gull in several Mediterranean colonies.This includes competition for nesting sites and predation of eggs (Oro and Martínez-Villalta, 1994b) and predation of nestlings and adults (Bradley, 1986;Monbailliu and Torre, 1986).
In 38 colonies of Balearic shearwaters studied, significant trends have been found, suggesting that there is competition for nest cavities and that Cory's shearwater (Calonectris diomedea) is dominant (Capellà, 1988).
Predation of chicks and eggs by rats is well documented for Mediterranean shearwater (Puffinus yelkouan) (Fernandez, 1979;Mayol, 1986).Balearic shearwaters breed on many islets colonised by rats, often with medium or high breeding success.Probably the effect of rat predation is more important on the smaller islets, where rodents reach higher densities.Stray cattle and dogs can also damage nests and young, and this is a big problem in several Italian colonies of Audouin's gull.Rats, foxes (Vulpes vulpes), cats and some reptiles can also pose a threat to the species.
Direct human impact such as the killing and/or collecting of eggs and chicks of Audouin's gull by local people and fishermen was formerly widespread but at present is of very little significance, although Audouin's gull eggs are still highly regarded in North Africa for confectionery.The harvesting of shearwaters was frequent until the late sixties, in Pitiusas (Ibiza and Formentera) (Mayol, 1985).Mainly the adults were collected because many pulli occupied inaccessible holes.From 2,400 to 2,700 adults per year were taken in Formentera until the 1960s.The increase in the human standard of living has resulted in a decrease in this practice, with probably fewer than 100 adults/year harvested.Although the species has been protected since the seventies, it is certain that some colonies are still harvested.
The breeding period of Audouin's gull overlaps with the tourist season on the Mediterranean coasts, and the increasing disturbance which this causes may represent a major future hazard for the species (Mayol, 1986;Thibault and Guyot, 1989) and for other syntopic seabirds.The easy accessibility of many colonies and the conspicuousness of the gulls and shag make them very vulnerable to disturbance by tourists, either by boating near the shore or by direct intrusion on the nesting areas.Birdwatching and research activities can also cause disturbance.
Illegal fishing with dynamite may be a problem locally.The use of lights for some fishing practices close to the colonies can negatively affect the behaviour of breeding Balearic shearwaters.Ambient light near important colonies can affect also adult behaviour and cause dazzling of fledglings.Mediterranean shag is a shy bird which is severely affected by frequent visits to the colonies.(Guyot, 1993).These threats are not only limited to colonies but also apply at roosting places.Despite legal protection, illegal prosecution of the Mediterranean shag is still frequent in some areas.
The high level of recorded oil pollution in the Mediterranean from incidental oil spills or illegal washing of tanks could have lethal and sublethal effects on adults and eggs through eggshell smearing.A serious oil spill during the breeding season near breeding colonies could be disastrous for Audouin's gull, while Balearic shearwaters gather in coastal areas near important harbours during moult and become very vulnerable to oil spills Chemical contamination is heavy in Mediterranean waters and represents a serious hazard for seabirds (Lambertini and Leonzio, 1986).High levels of heavy metals and chlorinated hydrocarbons (including dioxins, coplanar PCBs and dibenzofurans) have been found in Audouin's gull samples.High mercury levels were found in chicks in Asinara (Sardinia), and for several years the colony had a very low breeding success which finally led to its total disappearance.

Actions
The full list of actions and their priorities as identified by the experts compiling the action plans are given in Annex I.More general work areas which are common for all the three species are presented in Table 2. Action plans identify the need to influence fishery activities through EU policies as well as to undertake actions at national and local levels to reduce the impact of fishing on seabird species.
International and national legislation must be strengthened in order to reduce the level of oil and chemical pollution which affects the Mediterranean basin and is known to have negative impacts on the reproduction and survival of the species.The development of National Biodiversity and, more specifically, of coastal strategies, is the basis for a sustainable development of the Mediterranean coasts.Recommendation N°62 of the Standing Committee of the Bern Convention calls the contracting parties to develop national action plans for the species as a tool for proper implementation of their conservation.Key sites, identified through the IBA programme should become part of the Natura 2000 (EU) and Emerald (Council of Europe) networks, should be declared SPAMI (Barcelona Convention), become protected areas and be properly managed to reduce disturbance predation and to stop habitat loss.
Our knowledge on the distribution, ecology and movements of the species needs to be increased in order to identify, protect and monitor all key sites.Research needs to be carried out on the impact on seabirds of a number of factors, such as fishery, disturbance, interspecific competition or predation, which have been identified as actual or potential threats.
Exchange of information among researchers and conservationists must be continued and possibly improved and the Benidorm meeting is a good example of the implementation of this objective.
Finally, local communities, as well as decisionmakers, fishermen and tourists need to be made aware of the need to protect these species and their habitat through specific awareness and educational campaigns since all too often lack of knowledge is the reason for incorrect behaviour or activities.

CONCLUSIONS
The Species Action Plans provide all necessary information for planning and carrying out conservation activities for each species at all level.They are common documents which NGOs and Governmental agencies should agree to use as a base for common or co-ordinated work based on priority and urgency.They are "living documents" which provide a sound international background for developing more detailed national or local plans for actions covering all useful activities aimed at the conservation of the most endangered bird species in Europe.

TABLE 1 .
-Overview of the threats according to the Species Action Plans.

TABLE 2 .
-Overview of the actions identified in the Species Action Plans.Ensure adequate protection of the species Designation of key sites as Protected areas Undertake appropriate management Prevent disturbance and persecutionControl of competitors and predators (yellow-legged gull, rats, etc.)