Restoring agricultural prosperity

01/07/2024

Nestled along the northern coast of Tunisia is the picturesque Bizerte Lagoon, a stunning and biodiverse ecosystem teeming with marine life and cultural heritage.

This elliptical wetland connects to the Mediterranean Sea in the northeast via a natural 7-km inlet and a 15-km man-made canal. To the southwest, it links to the internationally significant Ramsar wetland and UNESCO-MAB reserve, Lake Ichkeul, via Oued Tinja. Its rich and diverse ecosystem thrives thanks to a mix of freshwater and marine water from various sources, including direct rainfall and runoff from streams. Its water dynamics change over time, with an average volume of 910 Mm3 and a daily exchanged volume of about 22 Mm3.

A fragilized ecosystem

Over the years, the lagoon has encountered various challenges that have slowed its path towards sustainable development. Rapid urbanization, industrialization, and the impacts of climate change have increased the pressure on the lagoon's ecosystem. However, these issues present opportunities for collaborative solutions. Efforts to address pollution from urban, industrial, and agricultural sources, along with managing fishing practices and protecting habitats, are essential to preserve and enhance this delicate ecosystem for future generations.

The biodiversity of the lagoon has evolved over time. The planktonic microflora and benthic macroflora now stand at 75 species, providing limited plant cover, mainly along the banks and in shallow areas. In 2020, the benthic macrofauna consisted of 156 species of invertebrates. Vertebrates, specifically fish, are represented by approximately 45 species, many of which are important for fishing. The abundance of non-indigenous species, of which there are currently 29, serves as a significant indicator of the effects of climate change.

Emerging impacts of climate change in the region are already evident and manifest in various phenomena. Changes in weather patterns, including variations in temperature and rainfall, are occurring. An accelerated rise in sea levels affects marine and lagoon areas. These changes are affecting ecosystems, leading to imbalances in lagoons, lakes, biodiversity, and ground and surface water. Further foreseen changes in the climate suggest a decrease in annual rainfall and an increase in average temperatures, with extreme weather events such as heavy rainfall and severe droughts expected.

The Bizerte Lagoon complex is especially sensitive to these changes, facing salinization, rising water levels, increased water temperatures, tropicalization of the ecosystem and increased marine water intrusion into Ichkeul. Agricultural practices, fishing, and shellfish farming are adapting to these new conditions. Additionally, there are some impacts on infrastructure and facilities that are being addressed.

The impact on livelihoods

The fisheries sector in Tunisia plays a crucial role in providing employment and meeting the nutritional needs of its population. With over 100 000 individuals employed in this sector, fisheries contribute significantly to the country's economy. Despite their importance, the productivity of coastal lagoons has faced some challenges over the years, impacting the country's ability to meet the growing demand for protein. These lagoons now produce around 450 tonnes annually, reflecting a shift in lagoon fishery production levels.

The Bizerte Lagoon, spanning approximately 12 800 ha with a mean depth of 4.06 m, has been particularly affected. Until the 1980s, untreated urban wastewater led to a decrease in production from 1 000 tonnes per year to around 200 tonnes per year. This decline highlighted the need for action to improve water quality and restore the ecological balance of the Bizerte Lagoon's aquatic ecosystem.

Capture fishery production from the Bizerte Lagoon also saw a reduction between 1995 and 2009, from 203 198 kg to 7 617 kg. By 2010, production was at 76.2 tonnes. These trends emphasize the importance of implementing effective fisheries management measures to support fish population recovery and ensure the sustainable productivity of the lagoon. 

Over the years, the lagoon has encountered various challenges that have slowed its path towards sustainable development. Rapid urbanization, industrialization, and the impacts of climate change have increased the pressure on the lagoon's ecosystem. However, these issues present opportunities for collaborative solutions. Efforts to address pollution from urban, industrial, and agricultural sources, along with managing fishing practices and protecting habitats, are essential to preserve and enhance this delicate ecosystem for future generations.

The biodiversity of the lagoon has evolved over time. The planktonic microflora and benthic macroflora now stand at 75 species, providing limited plant cover, mainly along the banks and in shallow areas. In 2020, the benthic macrofauna consisted of 156 species of invertebrates. Vertebrates, specifically fish, are represented by approximately 45 species, many of which are important for fishing. The abundance of non-indigenous species, of which there are currently 29, serves as a significant indicator of the effects of climate change.

Emerging impacts of climate change in the region are already evident and manifest in various phenomena. Changes in weather patterns, including variations in temperature and rainfall, are occurring. An accelerated rise in sea levels affects marine and lagoon areas. These changes are affecting ecosystems, leading to imbalances in lagoons, lakes, biodiversity, and ground and surface water. Further foreseen changes in the climate suggest a decrease in annual rainfall and an increase in average temperatures, with extreme weather events such as heavy rainfall and severe droughts expected.

The Bizerte Lagoon complex is especially sensitive to these changes, facing salinization, rising water levels, increased water temperatures, tropicalization of the ecosystem and increased marine water intrusion into Ichkeul. Agricultural practices, fishing, and shellfish farming are adapting to these new conditions. Additionally, there are some impacts on infrastructure and facilities that are being addressed.

The impact on livelihoods

The fisheries sector in Tunisia plays a crucial role in providing employment and meeting the nutritional needs of its population. With over 100 000 individuals employed in this sector, fisheries contribute significantly to the country's economy. Despite their importance, the productivity of coastal lagoons has faced some challenges over the years, impacting the country's ability to meet the growing demand for protein. These lagoons now produce around 450 tonnes annually, reflecting a shift in lagoon fishery production levels.

The Bizerte Lagoon, spanning approximately 12 800 ha with a mean depth of 4.06 m, has been particularly affected. Until the 1980s, untreated urban wastewater led to a decrease in production from 1 000 tonnes per year to around 200 tonnes per year. This decline highlighted the need for action to improve water quality and restore the ecological balance of the Bizerte Lagoon's aquatic ecosystem.

Capture fishery production from the Bizerte Lagoon also saw a reduction between 1995 and 2009, from 203 198 kg to 7 617 kg. By 2010, production was at 76.2 tonnes. These trends emphasize the importance of implementing effective fisheries management measures to support fish population recovery and ensure the sustainable productivity of the lagoon. 

FAO interventions 

FAO's initiatives in the Bizerte Lagoon have led to significant improvements in environmental health and socio-economic development. Key results include the successful establishment of an allocated zone for aquaculture within marine spatial planning (MSP) for shellfish farming. This effort has balanced conservation goals with economic development by delineating dedicated areas for aquaculture, providing a sustainable resource management blueprint.

Recognizing the complex interactions among stakeholders, particularly fishers and shellfish farmers, FAO has effectively implemented MSP. By defining specific zones for fishing activities and allocated zones for aquaculture, conflicts between uses have been minimized, and environmental impacts have been mitigated. This approach fosters sustainable blue growth and socio-economic development, aligning with the FAO Blue Transformation Roadmap.

FAO's focus on promoting seaweed and shellfish farming has harnessed the ecosystem services they offer, particularly in lagoon environments. These practices have significantly improved water quality and create vital nursery grounds for various species. Through different projects, FAO has developed tailored management plans and practical tools for stakeholders, encompassing a socio-economic development plan for the Bizerte Lagoon and a best practices guide for shellfish farming. By gathering and utilizing environmental, social, economic, and administrative data, these efforts assist decision-making processes. Moreover, FAO promoted seaweed aquaculture as a sustainable practice to enhance ecosystem services, climate change adaptation and employment opportunities.

To further address environmental degradation, FAO has supported initiatives such as the Integrated Depollution Programme. This programme aims to improve water quality and ecosystem health by tackling pollution from industrial, urban, and agricultural sources, laying the groundwork for sustainable socioeconomic development and ecosystem restoration. Through these comprehensive efforts, FAO is playing a crucial role in revitalizing the Bizerte Lagoon and ensuring its long-term sustainability.