Croatia - Schools Expeditions - Operation Wallacea

Croatia – Schools Expeditions

Croatia schools booklet

Structure of the expedition

This expedition combines both of these important areas with a week working in the spectacular Krka National Park and a second week on Mljet Island in southern Dalmatia off the coast of Dubrovnic.

During glacial times the main biodiversity refuges of Europe were the Iberian, Apennine and Balkans peninsulas which managed to conserve tropical elements of the flora and fauna. For example the nocturnal Cat Snake, which is closely related to other tropical species, is still found in the Balkans. The most important biodiversity elements of the present day Balkan region are the short but very large river valleys through the karst limestone areas and the biogeography of the numerous Adriatic islands.

Week 1: Krka National Park

During this first week the groups will spend a day each working on the following projects:

Fish surveys – this will be done from boat and foot based electrofishing surveys and netting surveys of various habitats along the Krka River. There are a number of endemic species including two endemic trout species (Salmo visovacensis and Salmo obtusirostris krkensi) that are being investigated. All fish captured will be identified, measured and genetic samples taken.

Reptile surveys – these surveys are performed from checking under previously placed cover boards and completing standard search times in different habitats and heights in the valley. The Park authorities are keen to determine how the Four lined snake (Elaphe quatuorlineata) which grows to 2.5m, the venomous Nose horned Viper (Vipera ammodytes) and the Leopard Rat Snake (Zamenis situla) separate their niches. In addition the surveys will be recording the distribution of the giant Glass Lizard (Pseudopus apodus), which grows to a length of 1.2m and tortoises (Testudo hermanni). Night surveys are also done for the Cat Snake (Telescopus fallax) which is the only nocturnally active snake species in the region.

Cave surveys – these surveys will be led by cave biology specialists in caves not open to the public and will involve completing transects and quadrats within the cave systems to estimate diversity of groups adapted to cave living. In addition soil samples from different parts of the cave system will be sorted in the lab to estimate soil biodiversity.

Bird and butterfly surveys – these surveys will involve setting mist nets from 6am to 12 noon at different heights in the valley. In addition point count surveys will be completed either side of the mist net from 7am to 9am each day. Target species for the birds include the Natura 2000 important bird species. After lunch the group will complete pollard surveys for the butterflies.

Mammal surveys – the large mammal species are surveyed using camera traps and searching areas for footprints and faecal samples. Within the Krka valley and surrounding plateau there are 2 large wolf packs and these appear to be reducing the jackal and fox populations. In addition to emptying the camera traps and analyzing the footage these teams will also be setting and emptying small mammal traps and in particular looking for the endemic vole (Dinaromys bogdanovi) found in the Dinaric mountains.

In addition to the fieldwork, the group will have a series of lectures covering Mediterranean Wildlife Ecology and Conservation and including presentations on freshwater fish speciation and survey techniques, reptile communities and niche overlap, apex predators and food webs in Mediterranean mammal communities, cave biodiversity, bird communities of the Mediterranean and threats to Mediterranean fauna and conservation initiatives. There will also be a seminar session on how to pursue a career in wildlife conservation.

Week 2: Mljet National Park

During their time in the Mljet National Park, students will complete one of the following options:

PADI Open Water dive training course: This course involves a combination of theory lessons, confined water dives and open water dives to gain an official scuba diving qualification.

Adriatic ecology course: Lectures cover topics such as Mediterranean fish and survey techniques, management of Mediterranean fisheries, the ecology and survey techniques for seagrass beds, invasive species and conservation in action – examples from the Mediterranean. Each lecture is accompanied by an in-water practical (diving or snorkelling).

Students will also participate in the following activities:

  • Helping with surveys and analysis of data from stereo video monitoring
  • Transect surveys to monitor tortoise populations in the Park
  • Assisting with seagrass monitoring surveys