The conservation of Posidonia seagrass beds and Coralligene reefs, is a main priority of Archipelagos’ research work, which aims to:

1. Produce detailed maps showing the location of Posidonia meadows and coralligenous reefs, based on which fishing grounds should be defined for large scale fishing gear, enabling the enforcement of the EU legislation protecting these unique habitats.

2. Collect biological data using an underwater digital cartographic camera system, providing:
• detailed information regarding the biodiversity and community composition of Posidonia meadows and coralligenous assemblages.
• evidence of damage and destruction
• photographic and video images of the seagrass beds and coralligene reefs, for use in public awareness campaigns.

3. Increase environmental awareness of Posidonia meadows and coralligenous reefs to enlist public support for their protection and to increase awareness of professional and recreational fishermen.

More specifically, since 2004, as part of the general marine conservation work carried by Archipelagos, research work has been implemented for the study of Posidonia meadows, including:

1. Mapping of seagrass beds: aiming to develop an efficient method for the monitoring of seagrass meadows, which could be applied on a large-scale, throughout the Mediterranean, Archipelagos, IMERAS, is carrying out pilot mapping of the Posidonia meadows in the eastern Aegean Sea. For the mapping, an underwater cartographic camera system is used that is connected to a monitor. Video data and still images from the camera, along with depth readings and GPS coordinates, show the presence/absence and status of the seagrass beds. Archipelagos, in collaboration with the Italian company of satellite technology applications Planetek, work together for the development of applications using satellite imagery as a tool for monitoring Posidonia seagrass beds. Satellite imagery data from IKONOS and ESA satellites are ground truthed with data from underwater mapping through, camera, sonar and visual census, for the development of a tool that can quantify sea grass meadows' size and density. This was applied at a pilot phase in the region of the Wildlife Refuge of Arki Island Complex, which is the nucleus of the under creation National Park of the North Dodecanese, with the aim at a later stage to have further application in other parts of the Greek seas and the NE Mediterranean.



2. Lepidochronological analysis: Archipelagos’ mapping surveys are coupled with lepidochronological studies, in order to assess the general health, age and status of the Posidonia seagrass beds. P. oceanica rhizomes and scales decay very little and can remain in the “matte” for millennia. After the leaves are shed, the dead sheaths remain on the rhizomes and variations in their thickness correspond to annual cycles. The study of these variations is called lepidochronology and it is a very effective tool for the study of Posidonia oceanica. Through lepidochronology, data can be obtained for estimation of growth rate and annual production of rhizomes, assessment of the number of leaves produced per year, leaf renewal cycle, detection and dating of previous flowering, as well as estimation of primary production.

3. Heavy metal analysis: Posidonia oceanica is a good indicator of heavy metals because leaves and rhizomes are able to accumulate metals such as mercury, copper, lead and cadmium. Analysis of the rhizomes are carried out to assess the heavy metal content and accumulation over time.
4. Permanent monitoring stations: permanent quadrats have been set up in a number of monitoring stations, in order to assess temperature and light intensity with the usage of loggers, as well as record changes in growth and productivity of the Posidonia meadows.
5. Analysis of the water quality: water samples are collected from the monitoring stations and analysed for their nutrient content (nitrate, nitrite, phosphate, phosphite, ammonia), as well as chlorophyll a, b, c and phaeopigments.
6. Development of pilot management proposals for the national and local authorities: The mapping ,lepidochronological, heavy metal and water analysis , as well as the permanent monitoring stations at Posidonia seagrass beds, aim to develop a monitoring tool, which will enable the direct conservation of these very important and rare ecosystems. At the same time, after all the aformentioned data are collected and analysed, a number of maps will be produced indicating the location and conservation status of the Posidonia meadows. Ιn collaboration with the national authorities, it will be possible to determine fishing fields, where the use of trawl fishing will be forbidden, as defined by European legislation (EU Fishing legislation: According to council regulation 1626/94 of 27/6/94, it is forbidden to fish with bottom trawls, seines or similar nets above Posidonia oceanica beds).

Research on coralligene algal assemblages has recently started by Archipelagos, and focuses on the preliminary mapping of assemblages, as well as their classification according to their biodiversity assessment.