How can we protect seagrass meadows? Posidonia oceanica plays a fundamental role in maintaining the balance of marine ecology. According to the IUCN Red List, Posidonia oceanica is classified as "Least Concern," but its distribution is gradually decreasing due to the threats it faces. The most accurate answer to how we can protect this species is to "preserve what already exists."
One of the approaches to marine ecosystem restoration is the transplantation (planting) of Posidonia oceanica, which has been practiced for many years along the Mediterranean and our country's coasts. In all trials, transplanted seagrasses have been uprooted from natural meadows and planted in different areas to observe whether they establish and survive in the planted area. While the survival rates of transplanted seagrasses vary annually, they generally remain very low, around 10%. Moreover, it has been observed in the discussion sections of these studies that such planting efforts do not yield meaningful results and, besides not contributing positively to the species and habitat, they also lead to the destruction of natural meadows.
Different results were not obtained from experimental trials conducted through the MERCES project completed by MCS. Even in fully controlled environments through cage experiments purged of external factors (damage caused by fishing gear, grazing pressures, and damage from dredging), the results remained unchanged. In fact, in some areas, it was observed that the transplanted seagrasses completely disappeared by the end of the second year of the experiment.
In conclusion, considering the studies conducted and the physical changes in marine ecosystems (such as increased seawater temperature, etc.), it is possible to say that planting efforts, especially for sensitive species like Posidonia oceanica, do more harm than good for their conservation. Instead of such approaches, approaches focused on conserving natural meadows in place will yield more effective results for species conservation. Restricting or even halting coastal constructions such as marinas, ports, and piers, which threaten seagrass meadows and cause mechanical damage, as well as fishing practices such as trawling and gillnetting that harm the seabed structure, will be much more effective in habitat conservation. The existence of marine protected areas also plays an important role in species conservation.
Seagrass meadows produce oxygen, store carbon dioxide, support biological diversity like forests, prevent coastal erosion, and can create new ecosystems by accumulating dead leaves on beaches.
The most effective way to protect seagrass meadows, endemic to the Mediterranean ecosystem, is to preserve what already exists.
You can click here to review the efforts of the Mediterranean Conservation Society towards the protection of seagrass meadows.
This article has been prepared in collaboration with Scientific Monitoring Expert Vahit Alan from the AKD team.