Activity category: Vulnerable species
Year: 2020
Type: Advocacy, Scientific research
Status: Ongoing
Target areas: Amvrakikos Gulf
Target organisms: Sharks, Rays
Project website:
Partners
Funders
Activity category: Vulnerable species
Year: 2020
Type: Advocacy, Scientific research
Status: Ongoing
Target areas: Amvrakikos Gulf
Target organisms: Sharks, Rays
Project website:
Partners
Funders
Objectives
By ElasmoCatch project focuses on the study and better understanding of the biodiversity and bycatch of sharks and rays in Greece, as well as the biology and ecology of these species. Its main objective is the collection of scientific data on their distribution, abundance, and interactions with fisheries with the final aim to delineate and implement effective management strategies for sharks and rays.
Description
Launched in 2020, the project initially focused on visits to small-scale and bottom trawling fishing vessels in the ports of North Aegean Sea, to document shark and ray catches. In 2021, the research expanded to include systematic data collection from small-scale fisheries in Chalkidiki Peninsula.
From 2022 onwards, the project has been carried out in Amvrakikos Gulf Since 2024, the ongoing fisheries-dependent data collection has been further enhanced by the inclusion of fisheries-independent data collection, customised protocols for video recording and visual monitoring of marine biodiversity of sharks and rays. The aim of the research now explores trophic relationships between species, bycatch rates correlated with the different fishing techniques, and analysis of the biological characteristics of each species, such as their growth rates.
Data collection follows the protocol of the General Directorate of Fisheries for monitoring bycatch of vulnerable species, adapted to the region's needs. Additionally, biological data on species morphology and reproductive maturity are gathered, along with genetic material. The project also investigates the impacts of bycatch on the health of captured individuals and collects data to estimate post-release survival rates for each species by fishing gear type, using tagging methods.
Results
A total of 1380 fishing trips have been monitored in Amvrakikos Gulf through onboard and landing site surveys. During the monitoring, a total of 2529 specimens belonging to nine ray species and one shark species were recorded interacting with fishing activities. Of these, 361 individuals were tagged using conventional tags, to assess post-release survival and habitat use. Observations from both onboard surveys and landing sites monitoring indicated that the majority of sharks and rays were alive when brought on the vessel. This finding was further confirmed by tag retrieval data, confirming post-release survival and suggesting that release may represent an effective management strategy for the area.
In total, 885 DNA samples and 739 stomachs were collected to investigate population structure and trophic ecology. Population genetic analysis of the Common Smoothhound Mustelus mustelus revealed that the population within Amvrakikos Gulf is genetically isolated from other Mediterranean populations, highlighting the importance of the area as a distinct management unit. These findings provide a scientific basis for the development of targeted conservation measures in the region.
Fishery-independent data collection included a total of 87 deployments of Baited Remote Underwater Video Systems (BRUVS), summing up to 115:30 hours of footage collected during both daytime and nighttime. The integration of fishery-dependent and fishery-independent data will allow us to have a more comprehensive understanding of the habitat use and spatial ecology of sharks and rays in Amvrakikos Gulf, increasing our knowledge on one of the most threatened groups of animals on Earth in one of the most critical habitats in the Mediterranean.