Argosaronic gulf

















The islands of Spetses and Hydra have a very strong nautical tradition both in crafting and sailing, with numerous events taking place in the region such as the “Spetses Classic Yacht Regatta”, "Armata" and "Miaoulia". This strong nautical tradition, as well as the fact that car use is restricted on the islands, makes them a popular destination for sailing boats and yachts. This activity is suspected to have a strong impact on the habitat of Posidonia oceanica as the anchorage is uncontrolled in all the coastal areas surrounding the island and port facilities are insufficient for the volume of visiting boats.


In 2022, iSea mapped Posidonia meadows in Spetses and Velopoula, an island located south of the Argolic Gulf, utilising high-resolution satellite imagery in combination with ground truthing data obtained during fieldwork. The mapping results for Spetses showed that the meadows cover a total of 3.73 km2 while for Velopoula a total of 0.356 km2. Both maps achieved accuracies > 90% with a spatial resolution of ~1.5 m.



In 2023, mapping of P. oceanica was conducted in Hydra island which resulted in a total seagrass coverage of 0.77km2, with a 72% accuracy and a spatial resolution of~0.5 m.



In 2024, iSea firstly aims to better understand the coverage and distribution of the endemic seagrass Posidonia oceanica in the Argosaronic Gulf and secondly to raise awareness among local stakeholders and the public regarding this precious habitat. This will be achieved by a) mapping Posidonia meadows around Poros island and Methana peninsula to inform decision-making and serve as baseline for future management and conservation, and b) by sensitizing local stakeholders.

Although the spatial extent of the meadows on Spetses island is vast, the meadows suffer from fragmentation and are degraded due to anthropogenic pressures. It is likely that the area in Kosta channel and the gulf of Zogeria used to be covered with meadows, as in both areas, the depth and the oceanographic conditions permit the growth of P. oceanica. This is highly possible, considering the heavy boat traffic and the anchor tracks identified within the region. The situation was similar in the channel between Spetses and Spetsopoula, the smaller island south of Spetses, while at the entrance of the old harbour, numerous litter items were observed including building materials and plastic items such as plastic bottles.

In Hydra the meadows' distribution is rather limited and this is mainly attributed to the characteristics of Hydra's coastline (intense storm and wave action, steep rocky continental shelf), which make it unsuitable for the settlement of a meadow. However, where Posidonia meadows are present, they appear mainly patchy and noncontinuous. In the beaches of Agios Nikolaos and Agios Georgios (Bisti) this may be the result of uncontrolled anchoring as the areas are a popular spot for boats. Furthermore, in Molos beach the pier structure attracts a higher boat activity which may have resulted in the limited distribution of P. oceanica within the bay, while the Palamidas beach shipyard may act as a pollution point possibly leading to the degradation of the meadow in the area. Nevertheless, the limited distribution of P. oceanica around the island of Hydra stresses the need to protect and restore the remaining meadows.


Find the project's reports below:
Informative Material:
Project's Team:
Roxani Naasan Aga – Spyridopoulou

Roxani Naasan Aga – Spyridopoulou

Roxani is an environmentalist, she holds a bachelor’s in Marine sciences from the University of Aegean. In 2019, she started working on projects for the “Aquatic Litter” and the “Vulnerable Species” departments. Currently, she is working as a Project Manager for projects regarding “Vulnerable Species” and “Human and Aquatic Ecosystems”.

Her main research interests are related to elasmobranch ecology and biology, fisheries biology, and marine protected areas. She holds a speedboat licence, and a diving licence and is multilingual (Greek, Arabic, English, and French). She knows how to code in R. She is a qualified user of ArcGIS and SNAP(ESA). Furthermore, she knows how to use software for ecological data (Vissim, Populus, Primer, Presence, Distance).

Before this, she used to work with humanitarian NGOs for refugees in Greece as a cultural mediator and interpreter.


Contact Info:

Email: [email protected] 

tel. +302313090696

mob. +306944505224 

Ilektra Athinaiou

Ilektra Athinaiou

Ilektra was born in 1998, she is from Nafplio and has completed her bachelor’s in Marine and Freshwater Biology at Edinburgh Napier University, while she recently graduated from her master’s degree in Marine Conservation from the University of Plymouth. Academically, she has focused on a range of topics and has completed her dissertation on elasmobranch trade in Greece in collaboration with iSea, while for her MSc thesis, she worked on shark and ray stock assessment approaches with Blue Resources Trust. She was previously involved with Archelon working first as a monitoring coordinator in Zakynthos and later as a project assistant in the Peloponnese. She volunteered with the Argolic Environment Foundation as a local admin and has participated as a diver in the cleanups of two “Prosfero” projects with iSea. She has knowledge on R, QGIS, adobe premiere and Wix, while she is a certified PADI Open Water Diver and BLS first aid responder and holds a drone license (A1/A3).

She has a range of interests, including blue carbon ecosystems, elasmobranchs, genetics and using technology for research. She speaks 3 languages: Greek (native), English (native) and basic Dutch. Within iSea she works as a Project Manager in the Vulnerable Species Pillar.

Contact Information:

Email: [email protected]

Phone number: +30 2313 090696

Kyriaki Pyloridou

Kyriaki Pyloridou

Kyriaki was born in 1999 in Thessaloniki. She has a bachelor’s degree from the Department of Oceanography and Marine Sciences, from the University of the Aegean. She speaks three languages: Greek (native), English (B2) and Chinese (beginner). She’s familiar with Microsoft Office applications, ArcGIS, R and she’s a certified PADI Open Water Diver. She conducted her internship at iSea in the summer of 2021, in the “Vulnerable Species” pillar and more specifically in the project “Sharks and Rays in Greece and Cyprus”. She’s working as an Assistant Project Manager. 


Contact Information:

Email: [email protected]

Tel. +302313090696