The study brings an overview of threats to the coastal ecosystem and marine biodiversity in the Ecological Network Area (NATURA 2000 site) HR3000003 Vrsar islands through an ecosystem based approach. An ecosystem approach is a strategic approach to the comprehensive and integrated management of human activities that affect the marine and coastal ecosystem based on the latest scientific knowledge. The purpose of such an approach is to optimize the use of the ecosystem without causing harm, with the aim of managing the ecosystem based on its properties and diverse uses.
Analysis of the current state within the terrestrial an marine habitats has been done.
The largest share of 55.32 % within the scope of the NATURA 2000 site HR3000003 Vrsar islands is occupied by the Infralittoral detrital bottom.
During the analysis of the current state of protected species, the following conclusions were reached:
In the area of the Vrsar Islands, field research has established the presence of five strictly protected (SP) plant species, including two endangered species (EN) (Carex extensa., Glaucium flavum) and two sensitive species (VU) (Desmazeria marina, Parapholis incurva), while one does not have a vulnerability status (Limonium cancellatum). In the area of the Vrsar Islands, field research has established the presence of three species of protected fauna (Lithophaga lithophaga, Pinna nobilis, Tursiops truncatus).
The analysis of the current state of the environment through segments of natural resources resulted in a segregation of existing pressures in the scope of the Study.
- Invasive species
Within the scope of the research, individual specimens of three invasive species of vascular flora were recorded (Bidens subalternans, Conyza canadensis, Datura stramonium). Of the invasive marine species, the most prominent are tentaculate ctenophore Mnemiopsis leidyi and the invasive species of alga Caulerpa cylindracea.
- Maritime transport
Maritime transport is a problem in the marine environment in form of underwater noise, the release of harmful substances into the air and into the marine environment, the transmission of marine organisms of invasive species through ballast water, anchoring, etc. There are three main negative impacts of ballast water: ecological (introduced alien species begin to dominate the new ecosystem and destroy biodiversity), economic (damage to fisheries, coastal industry and tourism) and the impact on human health. An example of the spread of invasive species in this way are a tentaculate ctenophore Mnemiopsis leidyi and an alga Caulerpa cylindracea, both present in the area.
According to the Master Plan of Istrian Tourism 2015 – 2025, in the Poreč-Parenzo cluster based tourist products are: sports, nautics, touring and events, in the Vrsar-Orsera – Funtana-Fontane cluster: exclusive tourist resorts, water sports, nautics, events and gastronomy. According to the data of the Central Bureau of Statistics, in the area of the mentioned three units of local self-government in 2018, there were a total of 66,041 beds. The number of arrivals and overnight stays in this area is constantly increasing, and in 2018, a total of more than one million arrivals and 6.5 million overnight stays were recorded.
The negative cumulative impact of the anthropogenic pressure on coastal and marine habitats and their biodiversity is mostly evident in the areas of ports open to public transport to which maritime shipping routes lead.
In order to successfully continue the monitoring of existing pressures, and in order to prevent their intensification, guidelines are prescribed in the chapter Proposal of guidelines and indicators for future monitoring of the state of the marine and coastal environment. The results obtained by this Study will contribute to the process of spatial planning of the marine area by achieving the objectives of integrated coastal zone management.