Are we overlooking Natura 2000 sites? Lessons learned from a transnational project in the Adriatic Sea

Since the adoption of the Habitats and Birds Directives by EU governments, marine Natura 2000 (N2K) sites have been established in the European Mediterranean Sea, creating one of the largest international networks of protected areas. Nevertheless, to date, marine N2K sites are generally scarcely implemented, studied and monitored, and thus their management effectiveness is weak, and their environmental status is often unknown. The Interreg Italy-Croatia ECOSS project aimed at establishing the ECOlogical observing system of the Adriatic Sea (ECOAdS), to integrate the existing research and monitoring activities in the area, and to promote data sharing at international level, for enhancing monitoring and conservation in Adriatic N2K network. In the framework of ECOSS, a conceptual model was developed and applied to selected N2K sites, to review the existing knowledge, assess site effectiveness, and suggest possible improvements in their monitoring and management based on the contribution that ECOAdS can provide to their implementation. Information on social, ecological, and oceanographic elements related to the conservation and management of these case studies was gathered by consulting the project partners involved in the management and monitoring of the sites and through a literature review. The results of this study revealed a discouraging condition with no management plan in most of the sites, while regulatory measures are generally in place but without surveillance. Monitoring activities are performed occasionally, and information on presence and status of protected species is often lacking or outdated. Although the N2K network provides a unique opportunity to advance marine conservation and achieve the 30% conservation target by 2030, the biggest challenge ahead is the proper management and monitoring of N2K sites. The proposed conceptual model may be taken as a framework to properly set up ecological observing systems in the N2K network and help overcome current limitations, integrating scientific research within the N2K conservation strategies

BOTTLENOSE DOLPHIN Tursiops truncatus (Montagu, 1821) POPULATION STRUCTURE IN THE EASTERN ADRIATIC SEA

Dobri dupin (Tursiops truncatus) jedini je morski sisavac koji trajno naseljava cijelo Jadransko more. Dosadašnja istraživanja ukazuju da je populacija u Jadranu strukturirana u lokalne zajednice, no njihova prostorna i društvena struktura nije bila opisana. Ova disertacija kroz tri znanstvena rada na temelju podataka prikupljenih foto-identifikacijom opisuje prostornu i društvenu strukturu populacije dobrog dupina duž istočne obale Jadranskog mora, istražuje čimbenike koji utječu na prostornu i društvenu strukturu populacije i po prvi put opisuje demografske parametre lokalne zajednice dobrog dupina u području sjeverne Dalmacije. U području od Istre do akvatorija otoka Visa utvrđene su tri zajednice dobrog dupina. Spol, jačina društvenih veza, nautički promet i koćarenje utvrđeni su kao čimbenici koji utječu na društvenu strukturu i područja obitavanja jedinki. Akvatorij sjeverne Dalmacije naseljava relativno mala, ali stabilna zajednica dobrog dupina. Ukupni rezultati ove disertacije podupiru pretpostavku o meta-populaciji dobrog dupina i daju smjer za daljnja istraživanja radi boljeg poznavanja ove vrste u Jadranu.The bottlenose dolphin (Tursiops truncatus) is the only marine mammal permanently inhabiting the whole Adriatic Sea. Previous studies suggest that the population is structured into local communities, but the social and spatial structure remained unknown. This dissertation is based on three publications that, based on photo-identification data, describe the social and spatial structure of the bottlenose dolphin population along the eastern Adriatic coast, determine factors influencing the social and spatial structure of the population, and, for the first time, describe the demographic parameters of a community inhabiting the waters of north Dalmatia. Three local communities have been determined in the area between the Istrian peninsula and the island of Vis. Gender, association strengths, leisure boat traffic and trawling are factors influencing the social structure and individuals' home ranges. The waters of north Dalmatia are inhabited by a relatively small, but stable bottlenose dolphin community. The summary results of this dissertation support the hypothesis of meta-population and provide guidelines for future research to better understand the status of this species in the Adriatic Sea

BOTTLENOSE DOLPHIN Tursiops truncatus (Montagu, 1821) POPULATION STRUCTURE IN THE EASTERN ADRIATIC SEA

Dobri dupin (Tursiops truncatus) jedini je morski sisavac koji trajno naseljava cijelo Jadransko more. Dosadašnja istraživanja ukazuju da je populacija u Jadranu strukturirana u lokalne zajednice, no njihova prostorna i društvena struktura nije bila opisana. Ova disertacija kroz tri znanstvena rada na temelju podataka prikupljenih foto-identifikacijom opisuje prostornu i društvenu strukturu populacije dobrog dupina duž istočne obale Jadranskog mora, istražuje čimbenike koji utječu na prostornu i društvenu strukturu populacije i po prvi put opisuje demografske parametre lokalne zajednice dobrog dupina u području sjeverne Dalmacije. U području od Istre do akvatorija otoka Visa utvrđene su tri zajednice dobrog dupina. Spol, jačina društvenih veza, nautički promet i koćarenje utvrđeni su kao čimbenici koji utječu na društvenu strukturu i područja obitavanja jedinki. Akvatorij sjeverne Dalmacije naseljava relativno mala, ali stabilna zajednica dobrog dupina. Ukupni rezultati ove disertacije podupiru pretpostavku o meta-populaciji dobrog dupina i daju smjer za daljnja istraživanja radi boljeg poznavanja ove vrste u Jadranu.The bottlenose dolphin (Tursiops truncatus) is the only marine mammal permanently inhabiting the whole Adriatic Sea. Previous studies suggest that the population is structured into local communities, but the social and spatial structure remained unknown. This dissertation is based on three publications that, based on photo-identification data, describe the social and spatial structure of the bottlenose dolphin population along the eastern Adriatic coast, determine factors influencing the social and spatial structure of the population, and, for the first time, describe the demographic parameters of a community inhabiting the waters of north Dalmatia. Three local communities have been determined in the area between the Istrian peninsula and the island of Vis. Gender, association strengths, leisure boat traffic and trawling are factors influencing the social structure and individuals' home ranges. The waters of north Dalmatia are inhabited by a relatively small, but stable bottlenose dolphin community. The summary results of this dissertation support the hypothesis of meta-population and provide guidelines for future research to better understand the status of this species in the Adriatic Sea

BOTTLENOSE DOLPHIN Tursiops truncatus (Montagu, 1821) POPULATION STRUCTURE IN THE EASTERN ADRIATIC SEA

Dobri dupin (Tursiops truncatus) jedini je morski sisavac koji trajno naseljava cijelo Jadransko more. Dosadašnja istraživanja ukazuju da je populacija u Jadranu strukturirana u lokalne zajednice, no njihova prostorna i društvena struktura nije bila opisana. Ova disertacija kroz tri znanstvena rada na temelju podataka prikupljenih foto-identifikacijom opisuje prostornu i društvenu strukturu populacije dobrog dupina duž istočne obale Jadranskog mora, istražuje čimbenike koji utječu na prostornu i društvenu strukturu populacije i po prvi put opisuje demografske parametre lokalne zajednice dobrog dupina u području sjeverne Dalmacije. U području od Istre do akvatorija otoka Visa utvrđene su tri zajednice dobrog dupina. Spol, jačina društvenih veza, nautički promet i koćarenje utvrđeni su kao čimbenici koji utječu na društvenu strukturu i područja obitavanja jedinki. Akvatorij sjeverne Dalmacije naseljava relativno mala, ali stabilna zajednica dobrog dupina. Ukupni rezultati ove disertacije podupiru pretpostavku o meta-populaciji dobrog dupina i daju smjer za daljnja istraživanja radi boljeg poznavanja ove vrste u Jadranu.The bottlenose dolphin (Tursiops truncatus) is the only marine mammal permanently inhabiting the whole Adriatic Sea. Previous studies suggest that the population is structured into local communities, but the social and spatial structure remained unknown. This dissertation is based on three publications that, based on photo-identification data, describe the social and spatial structure of the bottlenose dolphin population along the eastern Adriatic coast, determine factors influencing the social and spatial structure of the population, and, for the first time, describe the demographic parameters of a community inhabiting the waters of north Dalmatia. Three local communities have been determined in the area between the Istrian peninsula and the island of Vis. Gender, association strengths, leisure boat traffic and trawling are factors influencing the social structure and individuals' home ranges. The waters of north Dalmatia are inhabited by a relatively small, but stable bottlenose dolphin community. The summary results of this dissertation support the hypothesis of meta-population and provide guidelines for future research to better understand the status of this species in the Adriatic Sea

The Acoustic Repertoire of Bottlenose Dolphins (<i>Tursiops truncatus</i>) in the Cres-Lošinj Archipelago (Croatia): Site Dependent Diel and Seasonal Changes

Describing the acoustic repertoire of cetaceans is necessary to understand the functionality of their sounds and the effect anthropogenic pressures have on animals living in a marine environment. This study provides a description of the acoustic repertoire of bottlenose dolphins (Tursiops truncatus) in the Cres-Lošinj archipelago based on continuous 24-h recordings collected from two monitoring stations, both inside and outside the Natura 2000 Site of Community Importance, during an 8-day period in March/April 2020 and a 13-day period in July/August 2020. A total of 1008 h were visually and aurally analyzed to identify vocalizations and investigate diel and seasonal patterns in their parameters. Furthermore, sound pressure levels were calculated for the low (63 Hz–2 kHz) and high (2 kHz–20 kHz) frequency range. Bottlenose dolphins in the Cres-Lošinj archipelago were found to produce whistles, chirps, low frequency narrow-band sounds, burst pulse sounds, and echolocation clicks showing that dolphins are present at both monitoring stations, during both diel and seasonal periods, in a comparable manner. This paper also provides evidence that whistles, chirps, and low frequency narrow-band sounds change their parameters in relation to the background noise in the area, that varies according to diel and seasonal patterns. This suggests a vocal plasticity in the species and a coping strategy to avoid masking of relevant acoustic signals for the local population in the Cres-Lošinj archipelago

Characterization of the underwater noise produced by recreational and small fishing boats (&lt;14&nbsp;m) in the shallow-water of the Cres-Lošinj Natura 2000 SCI

Recreational boats are a dominant source of underwater noise in coastal areas, but reliable boat noise assessment is generally lacking. Here the Underwater Radiated Noise (URN) of seven recreational and small fishing boats moving at two different speeds was measured in the shallow waters of the Cres-Lošinj Natura 2000 SCI (Croatia). Measurements were undertaken considering the internationally recognized standards and published guidelines for shallow waters. URN was provided in 1/3 octave band spectra and in narrow band spectra, to highlight the tonal components. Engine power and type rather than the boat length and design result to be more predictive of URN. Highest speeds induce highest noise levels only in a very limited frequency range and different boats with similar speed but different engines show a shift in the spectra. Relevance of the achieved results for the tested area is further discussed

Table_1_An ecosystem-based system of variables to enhance marine species and habitat monitoring and conservation: The Adriatic Natura 2000 case study.docx

Implementing effective marine monitoring to detect and track ecosystem shifts, biodiversity alteration, and habitat loss is one of the most crucial challenges to meet the objectives set out by the Post-2020 Biodiversity Framework and by the United Nations Sustainable Development Goals. The lack of coordinated and harmonized monitoring frameworks at different spatial scales and their weakness in accounting for ecological processes, due to incomplete sets of monitoring variables, strongly hinder the achievement of conservation objectives. Here, we propose an approach to build a coherent ecosystem-based system of monitoring variables for target marine species and habitats. The approach is designed to integrate the existing monitoring frameworks set up by the Water and the Marine Strategy Framework directives, and the Essential Ocean and Biodiversity Variables, with the aim to contribute to their harmonization and implementation. Furthermore, by embracing a holistic vision, it aims to incorporate ecological processes and socio-ecological aspects, considering the benefits of public engagement through citizen science, and of the ecosystem services approach for policies’ implementation. The study stems from the Ecological Observing System of the Adriatic Sea (ECOAdS), which was developed in the framework of the Interreg Italy-Croatia project ECOSS, using as exemplary monitoring test cases two relevant conservation targets for Natura 2000 sites of the Adriatic Sea, the common bottlenose dolphin and seagrass meadows. We test the potential of this approach in guiding the prioritization of monitoring variables under ecosystem-based criteria, and provide insights into the benefits delivered by an integrated system of observatories’ networks and monitoring frameworks to support marine conservation at both local and regional scales. The proposed approach can be transferred to other contexts and scales to help build a common knowledge and monitoring framework for conservation and management strategies, saving costs by relying on available resources and on consolidated and long-lasting approaches that might converge towards global initiatives.</p

First assessment of underwater sound levels in the Northern Adriatic Sea at the basin scale

The protection of marine habitats from human-generated underwater noise is an emerging challenge. Baseline information on sound levels, however, is poorly available, especially in the Mediterranean Sea. To bridge this knowledge gap, the SOUNDSCAPE project ran a basin-scale, cross-national, long-term underwater monitoring in the Northern Adriatic Sea. A network of nine monitoring stations, characterized by different natural conditions and anthropogenic pressures, ensured acoustic data collection from March 2020 to June 2021, including the full lockdown period related to the COVID-19 pandemic. Calibrated stationary recorders featured with an omnidirectional Neptune Sonar D60 Hydrophone recorded continuously 24 h a day (48 kHz sampling rate, 16 bit resolution). Data were analysed to Sound Pressure Levels (SPLs) with a specially developed and validated processing app. Here, we release the dataset composed of 20 and 60 seconds averaged SPLs (one-third octave, base 10) output files and a Python script to postprocess them. This dataset represents a benchmark for scientists and policymakers addressing the risk of noise impacts on marine fauna in the Mediterranean Sea and worldwide