The Gyaros island marine reserve: A biodiversity hotspot in the eastern Mediterranean Sea.

Since July 2019, Gyaros island in the central Aegean Sea, enjoys the status of a partial Marine Protected Area (MPA), allowing for exploitation by small-scale fishers following specific spatio-temporal restrictions. The need for assessing the effectiveness of the MPA in the future, led MAVA Foundation to fund a knowledge survey project aiming to serve as a baseline for future reference. A series of experimental fishing surveys took place with static nets, the outcomes of which are presented herein. From June 2018 to September 2020, a series of 8 fishing excursions with a total of 40 experimental fishing sets with bottom static nets were realized in 5 set locations around Gyaros island, inside the MPA protection zone. A total of 75 species were identified; the most abundant species, in terms of biomass, being: parrotfish-Sparisoma cretense, red scorpionfish-Scorpaena scrofa, common spiny lobster-Palinurus elephas, red porgy-Pagrus pagrus, little tunny--Euthynnus alletteratus, Mediterranean moray-Muraena helena, lesser spotted dogfish -Scyliorhinus canicula, forkbeard-Phycis phycis, surmullet-Mullus surmuletus, common cuttlefish-Sepia officinalis and common Pandora-Pagellus erythrinus. A comparison with similar data in adjacent areas outside the MPA allowed for assessing the effectiveness of the MPA based on four indicators: species diversity index, species relative biomass index, key predator species abundance, and alien fish abundance. Based solely on the experimental fishing trials, the MPA seems to be functioning, since both species diversity and abundance were higher within the protected area. However, its performance may still not be considered as optimal, as this is indicated by the large proportion of undersized key predators (e.g. groupers), although more abundant and larger than the ones residing outside the MPA.

First record of the marbled ray, Dasyatis marmorata (Elasmobranchii: Dasyatidae), from Greece (central Aegean Sea).

BACKGROUND: Currently, seven dasyatid species have been described in the Mediterranean Sea: Bathytoshia lata, Dasyatis marmorata, Dasyatis pastinaca, Dasyatis tortonesei, Himantura uarnak, Pteroplatytrygon violacea and Taeniura grabata. Papaconstantinou (2014) listed four species of Dasyatidae occurring in Greece (P. violacea, D. pastinaca, D. tortonesei and D. centroura; the latter was a case of misidentification and it is currently identified as B. lata, according to genetic analysis). However, the marbled stingray (D. marmorata) was not amongst them. Here, the presence of D. marmorata was examined for the first time in Greece. NEW INFORMATION: The present study provides updated information on the geographical distribution of D. marmorata in the Eastern Mediterranean Sea. A juvenile male stingray was captured in February 2019, during an onshore survey in Maliakos Gulf, located in the central Aegean Sea, Greece. The ray was examined at the Fisheries laboratory of the Hellenic Centre for Marine Research (HCMR) in Athens and was identified as D. marmorata. Morphological characters were recorded and DNA barcoding was applied to confirm the species identification. The combination of the two methods verified the occurrence of the marbled ray in the Greek waters. This is the first record of D. marmorata from the Aegean Sea.