The continuity of seagrass meadows, key to the survival of dugongs despite human pressures

25/06/2025

Dugong feeding in a seagrass meadow. Credit: Ocean Image Bank-Anett Szaszi

A new study reveals that large groups of dugongs observed in the waters of Hawar (Bahrain) persist thanks to the presence of healthy, continuous, and unfragmented seagrass meadows. Actions aimed at conserving these habitats in a good state, therefore, become crucial to securing the survival of this species, classified globally as vulnerable.

Two large aggregations of dugongs — each composed of more than 50 individuals — remain stably in the warm, shallow waters surrounding the Hawar archipelago in Bahrain. Furthermore, at certain moments in this area, more than 500 individuals can be observed. A scientific study — co-led from the CEAB-CSIC and published in Aquatic Conservation — has analysed why these herbivorous marine mammals, which are highly sensitive to human pressures and classified as vulnerable at a global scale, are so strongly concentrated in this part of the Persian Gulf and how they successfully survive there.

The results dismiss the key influence of factors such as temperature. Instead, they highlight a crucial condition for the survival and attraction of dugongs in this part of the world: the presence of extensive, unfragmented, and healthy seagrass meadows. These meadows lie in shallow waters, are rich in phanerogams (seagrasses), and cover more than 400 square kilometres. These habitats provide food and refuge for dugongs, both in summer and in winter.

At the same time, the scientific team details the growing threats facing dugongs in this part of the world. There are direct risks, such as entanglement in fishing nets or collision with boats, and indirect risks, such as the degradation of their habitat and food source: seagrass meadows. The area is a traditional fishing ground where pressures have been growing, and harmful fishing methods are used. Furthermore, boating activity is heavy and on the rise. Coastal development also puts these meadows — and everything that depends on them — at risk.

The study, based on historical data, satellite images, habitat mapping and fieldwork, underscores the importance of limiting human impacts to conserving what has been demonstrated to be key to maintaining large groups of dugongs: the meadows that sustain them. Furthermore, it highlights that these submarine grasslands are not only crucial for the survival of these unique mammals, but for the proper ecological functioning of the whole area. For all these reasons, the authors warn of the need to regulate fishing, maritime activity and coastal development — in a cross-border collaboration — to conserve the seagrass meadows and, with them, the dugong population.

Researchers, led by Abdulqader Khamis (University of Barcelona) and Teresa Alcoverro (CEAB-CSIC), used a model that directly links the presence of large groups of dugongs to the quality and extent of seagrass meadows: the more continuous the meadow, the greater the groups of dugongs. It demonstrates that if the meadows diminish or become degraded, the local abundance of these animals drops, which in turn makes it more difficult for the meadows to remain healthy.

The authors advocate for “creating a marine protected area in the region — a transboundary area — managed effectively and subject to strict regulations on coastal development, fishing practices, and motorised boating. Cooperation is required from all stakeholders to help conserve this natural treasure.”

Through this research, the scientific community underscores the necessity to protect, by reducing human pressures, what forms the basis of one of the last refuges for dugongs in the world: the seagrass meadows that sustain them.