UNDERSEA - UNDerwatER Soundscape bEyond AIS

The Croatian Natural History Museum participated in the first call for standard projects within the Italy-Croatia Cross-Border Cooperation Program. Our project "UNDERSEA - UNDerwatER Soundscape bEyond AIS" was approved for funding and began in February 2024. The total project value is 2.2 million euros, with eight partners involved in the project. CNHM leads the activities of creating a reference database of dolphin echolocation clicks in the Adriatic Sea and recording underwater sound in the South Adriatic Basin.


Project name: UNDERSEA - UNDerwatER Soundscape bEyond AIS
Project Code: ITHR0200399
Funding: Interreg Italy-Croatia 2021-2027
Duration: February 1, 2024 - July 31, 2026
Total Budget: € 2,219,960.00
CNHM Budget: € 164,910.00


The UNDERSEA project is a joint initiative of eight partners from Croatia and Italy aimed at enhancing sustainable development in the Adriatic Sea area by strengthening international mechanisms for monitoring, assessing, and mitigating marine environmental pollution caused by underwater noise in accordance with the EU Marine Strategy Framework Directive (MSFD) and the UN Convention on the Law of the Sea (UNCLOS). Underwater pollution by noise generated from human activities such as maritime traffic, tourism, fishing, and marine resource exploitation can pose significant threats to marine ecosystems. Between 2014 and 2019, levels of underwater noise in EU waters, particularly in the Adriatic Sea, doubled, indicating an urgent need for action.


Building on the foundations laid by the SOUNDSCAPE project, the UNDERSEA project aims to establish a comprehensive network for measuring sound in the underwater environment covering the entire Adriatic Sea. When analysing the impact of maritime traffic, a particular challenge is identifying the distribution of recreational and small vessels that do not have an Automatic Identification System (AIS), making it impossible to track them in space and determine their contribution to noise in the marine environment. Therefore, the project will conduct targeted experiments to assess the level of noise produced by recreational and fishing vessels. Using satellite data, the spatial distribution of small vessels will be determined, and tools will be developed to quantify their contribution to the overall noise measured by recorders deployed in the sea.


During the project, partners will install passive acoustic recorders at more than 15 locations in the Adriatic to continuously record sounds in the sea over the course of one year to provide insight into the Adriatic's acoustic environment. To assess the risk of noise impact on marine mammals, researchers from CNHM, in collaboration with researchers from the Blue World Institute), will analyse the collected recordings to determine the presence of Cetaceans in the sound recording areas. Since sound is recorded 24 hours a day for one-year, automated methods are needed to efficiently analyse this data, particularly for extracting dolphin echolocation clicks. For automatic extraction of echolocation clicks, we will create the first (reference) database of Adriatic dolphin echolocation clicks, including sperm whale and Cuvier's beaked whale and bottlenose, common, striped, and Risso's dolphins. The database will contain descriptions of average click characteristics for each species, and the collected data will be available as a reference for species identification in sound recordings collected during other project activities as well as other acoustic research.


Our aim is for the project results to establish new and innovative tools for cross-border management of the marine environment, coastal areas, and natural resources.


For further inquiries, please contact:


Asst. Prof. Draško Holcer, Ph.D., Senior Curator

Project Coordinator

Email: drasko.holcer@hpm.hr


Renata Brezinščak, Ph.D., Museum Advisor

Communication Coordinator

Email: renta.brezinscak@hpm.hr



Institute of Marine Sciences (ISMAR), National Research Council (CNR) (Italy)

Blue World Institute for Marine Research and Conservation - BWI (Croatia)

Institute of Oceanography and Fisheries – IOR (Croatia)

Regional Environmental Protection Agency of Friuli Venezia Giulia – ARPA Friuli Venezia Giulia (Italy)

Cetacea Foundation (Italy)

Apulian Regional Agency for Environmental Prevention and Protection - ARPA Puglia (Italy)

Public Institution for the Management of Protected Nature Areas of the Dubrovnik-Neretva County (Croatia)

Croatian Natural History Museum – CNHM (Croatia)


PROJECT IS FINANCED: Interreg Italy-Croatia Programme





The first meeting of the #UNDERSEAproject partners was held in the premises of the Institute for Marine Science (CNR ISMAR) at the Venetian Arsenal. Representatives from CNHM, including Asst. Prof. Draško Holcer, the project coordinator, and Dr. Renata Brezinščak, the communication coordinator, participated in the meeting. At the start of the meeting Ms. Helena Brčić from the program secretariat of the Interreg Italy-Croatia program greeted the partners. Afterwards the project coordinators provided an overview of the project and administrative procedures aimed at efficient project management and reporting. Subsequently, leaders of individual work packages held brief presentations on planned activities.


During the second day, a project Steering committee meeting took place, followed by the First workshop on the installation and use of acoustic recorders. Among other topics, partners discussed the calibration, maintenance, and deployment of passive acoustic recorder devices, as well as the locations for their placement. Partners who had not previously used recorders in marine environments gained practical familiarity with the devices, including their programming and operation.