Cameras and GPS to track rare seabird in Brijuni National Park

(Photo: Brijuni National Park)

A comprehensive field study of the Mediterranean shag has been carried out in recent days within Brijuni National Park, marking an important step in the protection of one of the Adriatic’s most significant seabird species.

The research was conducted in cooperation with ornithologists from the BIOM Association as part of the project “Small Islands for Biodiversity Conservation”. The initiative is financed under the Competitiveness and Cohesion Programme 2021–2027 and focuses on improving the management of protected areas and Natura 2000 ecological network sites.

Survey of Nesting Colonies

Field teams surveyed the breeding population of the Mediterranean shag (Gulosus aristotelis desmarestii) across 11 uninhabited islands within the park. Researchers counted nesting pairs and recorded active nests, providing updated data on the species’ status in the area.

(Photo: Brijuni National Park)

The absence of permanent human presence on these small islands offers favourable nesting conditions, allowing the birds to breed with minimal direct disturbance.

The Brijuni archipelago forms part of the Natura 2000 site “Aquatorium of Western Istria”, designated for bird conservation. The Mediterranean shag is one of its key target species. Conservation and research activities are coordinated across the wider marine area in cooperation with three public institutions: Public Institution Brijuni National Park, Public Institution Natura Histrica and Public Institution Kamenjak.

(Photo: Brijuni National Park)

A Species of European Importance

The Mediterranean shag is listed in Annex I of the EU Birds Directive (2009/147/EC), highlighting its high conservation value. As a top predator in coastal waters, it is regarded as an important indicator of the health of marine and coastal ecosystems.

Cameras and GPS Tracking

During the fieldwork, cameras were installed at selected nests to monitor breeding success and identify potential threats. In early spring, researchers plan to ring birds and fit GPS devices to track their movements and diving behaviour.

The aim is to determine key feeding grounds, measure distances travelled from nesting colonies and better understand the birds’ spatial needs. Since seabirds do not recognise administrative boundaries, such data underlines the importance of coordinated conservation measures at both local and regional levels.

(Photo: Brijuni National Park)

Marine Waste and Environmental Pressures

Researchers also observed negative environmental pressures in the field. On islands exposed to strong wave action, the sea deposits significant amounts of marine litter. Plastic mesh and other waste materials were recorded within nests, posing a potential danger to both adult birds and chicks.

The project therefore includes marine conservation measures, such as removing discarded fishing gear from the seabed, which can entangle birds during feeding dives.

(Photo: Brijuni National Park)

In addition, scientists will monitor coastal fish communities, which serve as indicators of ecosystem health and food availability for seabirds. Strengthening marine surveillance is also planned, a crucial step for safeguarding fish stocks, species dependent on them, such as the Mediterranean shag, and maintaining overall marine ecosystem balance.

(Photo: Brijuni National Park)

Ongoing Monitoring

The field research was accompanied by biologists Martina Hervat and Ana Markić from the Public Institution Brijuni National Park, ensuring continuous monitoring of natural conditions and the collection of data vital for future conservation planning.

(Photo: Brijuni National Park)