The Water Guardian
Coastal wetlands: the case of Ghar El Melh, Tunisia
From salt marshes to lagoons and river deltas, Mediterranean coastal wetlands are one of the most valuable, diverse and richest habitats in the world. For centuries, wetlands have been preferential areas for establishing human settlements, since they provided key ecosystem services such as access to freshwater and food, protection against storms and erosion, as well as the basis for economic activities such as commerce.
Yet, these coastal treasures and reliable guardians of water are among the most threatened natural systems worldwide. Imperilled by landfills, drained for agricultural practices or damaged for urbanization and tourism development, coastal wetlands are being degraded and destroyed at an alarming rate. The situation is particularly worrying in the Mediterranean, where only a few of these valuable ecosystems remain. In the region, urban planning is one of the main threats: since estuaries are close to beaches, they often disappear as cities expand.
Guardians of a sustainable future
Nature has many of the answers we need to tackle current and future societal and environmental challenges. A wide range of these Nature-based Solutions are provided by coastal wetlands. When kept healthy and managed efficiently, these ecosystems can be key to prevent disasters by controlling water flows. They also help to mitigate coastal erosion and river flooding, besides serving as a source of drinking water and food, and playing a key role as natural breeding sites for several species, including fish.
The case of Ghar El Melh
A Phoenician colony, a Roman city, a temple for Apollo and even a pirate base for the Barbary corsairs: who would have guessed that Ghar El Melh, a discreet town on the north coast of Tunisia, was the stage of Robert Blake's naval battles and stories of Roman mythology? Ghar El Melh (Arabic: غارالملح, which means "salt grotto", due to its proximity to salt pans) has been called Rus Eshmun, Rusucmona, Castra Laila, Delia, Porto Farina... Several civilisations and several names, but throughout its rich history, one single witness and stage: a unique coastal wetland.
Today, the coastal wetland of Ghar El Melh is one of the pilot sites for conserving and protecting coastal wetlands in the Mediterranean region.
A hidden gem in North Africa
Situated in Tunisia, about 50 km north of Tunis and 40 km east from the town of Bizerte, this coastal wetland was originally a sea bay, a vestige of the Gulf of Utica that is nowadays almost completely filled by the sediments of Oued Medjerda - the most important river in the north of the country.
The lagune of Ghar El Melh. In the background, Djebel Nadhour and the town of Ghar El Melh. Photo by Ugo Mellone
The lagune of Ghar El Melh. In the background, Djebel Nadhour and the town of Ghar El Melh. Photo by Ugo Mellone
Built at the foot of the Djebel Nadhour mountain, the village of Ghar El Melh currently has a population of 5,000 inhabitants. Besides its importance as a historical site, it is popular for its long sandy beaches, like the beach of Sidi Ali el Mekki, located five kilometers to the east of the village, on the southern side of the Cape of Sidi Ali el Mekki, and the beach of Chott Coucou, the lido that separates the lagoon from the Mediterranean Sea.
The beach in the south of the peninsula of Sidi Ali El Mekki regularly tops the charts of the most beautiful beaches in Tunisia. Photo by Ugo Mellone
The beach in the south of the peninsula of Sidi Ali El Mekki regularly tops the charts of the most beautiful beaches in Tunisia. Photo by Ugo Mellone
In 2007, the lagoon of Ghar El Melh and the delta of Oued Medjerda were designated as a Wetland of International Importance by the Ramsar Convention. In addition, in 2018, the town of Ghar El Melh received the Wetland City Accreditation Award and with this recognition, it has become the first Arab and North African city on the Ramsar list of accredited cities.
Some areas of the site have also been identified as a Key Biodiversity Areas (KBA) based on the presence of globally threatened species and significant populations of endemic plant species like Linaria heterophylla var. dichroa, which appears to be a new subspecies and has not yet been formally assessed.1
Linaria heterophylla var. dichroa. Photo by Errol Véla, CC-BY-SA
Linaria heterophylla var. dichroa. Photo by Errol Véla, CC-BY-SA
The diversity of terrestrial species of this coastal wetland is particularly high: birds, reptiles and more than 230 vascular plant species can be found here, several of which are threatened.1
Amongst the plant species, we can find a rare species of thyme, unique to Tunisia, and a highly valued variety of rosemary, Rosmarinus officinailis var. prostatus, used for cooking and for its medicinal properties.3
Habitats of Ghar El Melh
Ghar El Melh is a highly complex and dynamic wetland with a rich contrast of habitats - from rare and almost intact woodlands to rocky shores, salt marshes, coastal dunes, agricultural land and water bodies. Besides the delta of the Medjerda river, the site includes a large lagoon rich in fish, a secondary lagoon known for ancestral traditional agricultural practices, and alluvial plains.
Unfortunately, apart from some areas close to Djebel Nadhour and parts of the saltmarsh and coastal dunes at the south of Ghar El Melh Lagoon, all habitats in the area have been dramatically modified and degraded. All areas of the plain where the soil has low levels of salinity have been converted to agriculture or settlements.1
Note: To view the legend of the following map, please click on the arrows on the upper left corner. This map includes complementary data from studies held in 2015 and 2018.
Habitats of Ghar El Melh
illustrative examples
Dunes, forests, shrubs,
scrublands and maquis
The cape of Ras et-Tarf or Sidi Ali El Mekki (in Arabic : رأس سيدي علي المكي) points East and constitutes the northern entrance to the Gulf of Tunis. This peninsula is an exceptional area of dunes and woodland that supports a wide range of plants and reptiles. It has been declared a Key Biodiversity Area due to the presence of Linaria heterophylla “var. dichroa", an endemic plant of northeast Tunisia present in the shrubs, scrublands and maquis, and Acanthodactylus blanci, a very rare Endangered reptile present in the coastal dunes and backshore.
Canals, water courses
and the coastal lagoon
The biggest lagoon of the coastal wetland - the Ghar El Melh Lagoon - is rather shallow (<1.9 m deep) and quite strongly saline (37-42 ‰) due to the broad connection to the sea.3
The lagoon of Sidi Ali el Mekki, locally known as Sebkha of Sidi Ali el Mekki, is situated northeast of the coastal wetland. It is shallower (< 0.55 m deep) and more strongly saline (40-60 ‰) with a sandier substrate.3
The margins of the lagoons support a broad range of terrestrial species. Moreover, the connection to the sea supports great diversity, with 18 plants species4 recorded, including small plants of Posidonia oceanica.
A closer look at the islets of the lagoon reveals the presence of agricultural activity. Besides supporting a variety of terrestrial species, the islets actually host an ancestral agricultural practice: ramli or guettayas. On 15 June 2020, this unique agricultural system was recognized as Globally Important Agricultural Heritage Systems (GIAHS). The GIAHS programme has been designed by the UN Food and Agriculture Organization (FAO) to preserve traditional yet innovative agricultural practices.
Threats
Today, the Ghar El Melh wetland is subject to serious degradation mainly due to human activities. The decline in water quality is one of the main threats. The construction of dams and the change of the course of the Medjerda river towards the south have reduced the freshwater inflow, while the increase of wastewater discharge is severely destabilizing the delicate ecological balance of the lagoon. Illegal construction projects and coastal development, often due to increasing tourism pressure, are also significant threats. Unfortunately, most of these threats will probably be exacerbated by climate change.1
The following pictures reveal some examples of the threats to the coastal wetland of Ghar El Melh: recent and often illegal settlements on the fragile dunes ecosystems, water pollution and invasive species.
Settlements on dunes. Photo by Errol Véla, CC-BY-SA
Settlements on dunes. Photo by Errol Véla, CC-BY-SA
Water pollution. Photo by Richard Lansdown
Water pollution. Photo by Richard Lansdown
Settlements on dunes. Photo by Errol Véla, CC-BY-SA
Settlements on dunes. Photo by Errol Véla, CC-BY-SA
Recent settlements. Photo by Richard Lansdown
Recent settlements. Photo by Richard Lansdown
Carpobrotus edulis (with yellow flowers), an invasive plant species present in Rass Tarf. Photo: Errol Véla, CC-BY-SA
Carpobrotus edulis (with yellow flowers), an invasive plant species present in Rass Tarf. Photo: Errol Véla, CC-BY-SA
Taking action
Despite the high ecological value of Ghar El Melh’s coastal wetland, the status of its habitats and species has not been yet fully assessed. Improving our knowledge of this site is fundamental to understanding how species and habitats are coping with the growing human pressures which they are subject to. A comprehensive, accurate and updated characterization of the terrestrial biodiversity is one of the first necessary steps towards determining what actions need to be implemented both to preserve this coastal treasure and assess its status.
The project GEMWET- Conservation and sustainable development of coastal wetlands with high ecological value: the Ghar El Melh case, Tunisia, coordinated by WWF Tunisia and funded by the MAVA Foundation for Nature, has embarked on this important work. In December 2019, this project released a study4 about the terrestrial habitats of the Ghar El Melh area, which has highlighted a need to collect more data, particularly on the vegetation of the saltmarsh and dunes, and to provide a comprehensive assessment of the conservation of plants in the KBA. The study also emphasized three paths of action to better protect the highly degraded habitats of this coastal wetland:
- Developing a proper conservation management plan including a hydrological assessment, as the most effective method to achieve most actions needed in the area.
- Restoring flowing water courses to reduce pollution.
- Reviewing wastewater processes to inform upgrades and better facilities to reduce pollution in the lagoons and coastal waters.
The IUCN Centre for Mediterranean Cooperation (IUCN Med) collaborates in the GEMWET project through its Species programme, but also via the MEET Network. As such, it will support the GEMWET project through the establishment of best practices for tourism, developing an ecotourism package in Ghar El Melh wetland which will adhere to the MEET Network methodology and principles.
Would you like to learn more?
Projects
GEMWET Tunisia
IUCN Med projects with KBAs
Websites
The IUCN Red List of threatened SpeciesTM
OffYourMap: The case of Coastal Wetlands
The Ramsar Convention
The Ramsar Sites Information Service
MedWet STN
Tour du Valat
The Mediterranean Wetland Observatory
World Database of Key Biodiversity AreasTM
Integrated Biodiversity Assessment Tool (IBAT) - a multi-institutional programme of work involving BirdLife International, Conservation International, IUCN, and UNEP-WCMC.
FAO Globally Important Agricultural Heritage Systems (GIAHS)
Freshwater key biodiversity areas in the Mediterranean basin hotspot Mediterranean Wetlands Outlook 2: Solutions for sustainable Mediterranean Wetlands, 2018
References
1 IUCN, 2019. Characterisation and conservation assessment of terrestrial habitats at Ghar el Melh. By Lansdown, R.V., Daoud-Bouattour, A., Ghrabi-Gammar, Z., Ben Haj Jilani, I. and Véla, E. Project GEMWET, Málaga: 27 pages + annexes.
2 BirdLife International (2020). World Database of Key Biodiversity Areas. Developed by the KBA Partnership: BirdLife International, International Union for the Conservation of Nature, Amphibian Survival Alliance, Conservation International, Critical Ecosystem Partnership Fund, Global Environment Facility, Global Wildlife Conservation, NatureServe, Rainforest Trust, Royal Society for the Protection of Birds, Wildlife Conservation Society and World Wildlife Fund. Available at www.keybiodiversityareas.org. [Accessed 04/06/2020].
3 The Ancestral Wetlands of Ghar El Melh: Feeding the Mind, Body and Soul. OffYourMap [Accessed 11/06/2020]
4 Scapini, F., Boffa, J. M., Cassar, L. F., Conrad, E., and Nardi, M. 2008 Sustainable management of Mediterranean coastal fresh and transitional water bodies: A socio-economic and environmental analysis of changes and trends to enhance and sustain stakeholder benefits. International Conference of the WADI project (INCO-CT2005 015226), Malta.
5 Shili, A., Trabelsi, E.B. and Ben Maïz, N. 2002 Benthic macrophyte communities in the Ghar El Melh lagoon (North Tunisia). Journal of Coastal Conservation 8: 135-140.
Acknowledgements
A story by
Catherine Numa
and Cecilia Saura Drago
for
IUCN Centre for Mediterranean Cooperation
with the valuable contribution of
Richard Lansdown, Errol Véla, Ridha Ouni and Khouloud Ben Charfi
This web story has been edited by IUCN-Med and its partners as part of the GEMWET Project «Conservation et développement durable des zones côtières humides à haute valeur écologique ». The GEMWET project is the product of a partnership between WWF, BirdLife Europe, Tour du Valat, IUCN-Med, CAR-PAP, Global Water partnership Mediterranean (GWP-Med), AAO/BirdLife en Tunisie et INAT, with financial support from the MAVA Foundation.
GIS maps styling: Cecilia Saura Drago
Infographics: Cecilia Saura Drago for IUCN
IUCN Centre for Mediterranean Cooperation
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