Planting the underwater gardens of the Aegean

by Kleopatra Delaveri / Wednesday, 25 November 2020 / Published in Marine Conservation, News, Press Releases

An important stage in replanting Posidonia seagrass meadows was completed by Archipelagos Institute of Marine Conservation on the island of Lipsi, Greece, just before the new restrictions due to the COVID-19 pandemic were put in place.

Over the years we have become used to hearing about the increasing rate with which animals and plants are becoming extinct. This replanting focuses on developing practical solutions to help reverse this trend. Archipelagos is about driving solutions to create positive change.

Although Posidonia meadows are supposed to be highly protected in the Mediterranean, here in Greece we have tolerated their destruction for too many years – either because of ignorance or vested interests. We need to recognize their inherent value as an irreplaceable natural resource before it’s too late.

These seagrass meadows which are characterized by very slow growth rates are being damaged through destructive anchoring and fishing practices, as well as by coastal developments that increase the cloudiness (turbidity) of the water stopping sunlight penetration.

The destruction of Posidonia has many impacts, such as erosion of beaches and decreasing fish catches, as Posidonia meadows are vital nurseries. And, as recent investigations have shown, seagrass meadows can absorb up to 35 times more carbon than rainforests. In destroying the meadows we are losing a natural carbon sink needed to fight climate change.

The replanting took place in the Aegean Marine Life Sanctuary that is being created by Archipelagos on Lipsi. After 3 years of experimental planting by the Institute, in collaboration with scientists from the University of Essex in the UK, we have developed an innovative underwater replanting methodology. It is based on low-cost and high-yield practices, through which extensive planting can be implemented in large maritime areas using natural and biodegradable materials.

Archipelagos aims to spread the know-how it has developed, and encourage planting Posidonia meadows in other parts of the Aegean and Mediterranean thus making a significant contribution to reversing the destruction of these underwater forests.

The replanting of the Posidonia meadows required the coordinated work of a 25-member, international research team. Divers, snorkelers and kayak teams, undertook the transport and planting of this underwater garden.

The project took months of intense planning. From coastal waters in the area, we collected fragments of Posidonia plants that had been uprooted after heavy sea turmoil and from damage caused by destructive anchoring. The fragments were re-planted in the appropriate medium land before being located at their final underwater destination.

Posidonia meadows should be recognized as one of the key natural ecosystems that play a critical part in maintaining the health and productivity of Greece’s natural marine and coastal environment. In accepting our collective responsibility we can protect these meadows and develop solutions that will reverse the trend of their degradation.

Anastasia Miliou for Archipelagos Institute of Marine Conservation

Research and action for the protection of the Posidonia oceanica meadows, has been one of the main areas of focus for the “Archipelagos” Institute of Marine Conservation, for the past 15 years. In collaboration with the United Nations Regional Office for the Mediterranean (UNEP/MAP SPA/RAC) and the Department of Biology of the University of West of England, Bristol, we are creating detailed maps of the exact location, extent, and condition of protected ecosystems like this, using state-of-the-art technology. This way we contribute to filling significant knowledge gaps regarding these habitats in the Greek seas. At the same time, in collaboration with the Department of Biology of the University of Essex, UK, for the past 3 years we have been implementing experimental planting of seagrass meadows, while also using logger-based systems to record and quantify the ability of the Aegean Sea’s Posidonia beds to uptake carbon.