Expedition Information

Croatia Research Objectives

Krka National Park

The high Dinaric Arc mountains which run along the border of Bosnia and Croatia separate much of the European continental fauna from the Mediterranean fauna of coastal Croatia. The Krka River in only 60 km runs from the high Dinaric mountains down to the sea and contains an excellent example of this speciation gradient. The National Park is rich in freshwater biodiversity because of the long geographical isolation of the catchment and has around 20 unique species of fish to the river. Since much of the water in the karst (limestone) region is found underground, the cave systems and this habitat provides the highest rate of new species discoveries from any habitat in Europe. One of the unique cave species is the blind Cave Salamander featured in a 2012 David Attenborough film of 10 species to be include in an imaginary conservation Ark. The salamander is the third most genetically distinct amphibian in the world with its closest relative found now in the Yucatan Peninsular of Mexico having separated 200 million years ago when Pangea supercontinent was separating.

The Krka National Park authorities have established a research base station in the centre of the valley that they want to develop into a central biodiversity research hub for the eastern Adriatic region. Two new museums have been built on the site to illustrate the unique ecology of the valley and also the historical context since there are numerous Roman sites in the Park and surrounding plateaus. The Opwall role in this plan is to develop the most detailed biodiversity annual monitoring programme of key taxa yet undertaken in Croatia and from this programme to examine community structure and changes over time. In particular the research objectives are:

  • To quantify the effect on jackal, fox and other mammal fauna of the recent return and increase in wolf populations in the region
  • To determine how the effect of height in the valley affects the bird and reptile communities
  • To help quantify the biodiversity of the unique cave fauna
  • To quantify the fish communities and habitat associations in the Krka River.

Mljet National Park

The Mljet National Park is the oldest marine national park in the Mediterranean and was designated in 1960 to protect the largest Cladocera caespitosa reef within the Mediterranean. Mljet Island is one of the most beautiful of the Croatian Islands with large stands of Holm Oak and Aleppo Pine forest. The Mljet National Park has established a research centre at the north western tip of the island and Opwall is helping to build up the research outputs with initial concentration on:

  • Monitoring changes in fish communities using stereo video within the proposed No Take Zones and immediately adjacent to them
  • Determining the distribution and quality of the Posidonia seagrass beds around the island
  • Quantifying the tortoise populations within the Park.