Invasive alien species

In 2012, PRZHT (Pôles Relais Zones Humides Tropicales) initiated Project REMA, an effort dedicated to the conservation and rehabilitation of ponds in the Antilles, with backing from the IUCN. Wetland ecosystems in Martinique and the Caribbean had long been overlooked. However, interest in these habitats grew after PRZHT introduced an interactive virtual tour of Antilles ponds in 2019. Project REMA emerged in response to local concerns about the lack of technical resources for pond restoration in the French West Indies. While similar initiatives had been undertaken in France, there was no specific guide tailored to this region. Though originally conceived in 2012, the project remained dormant for several years before fully launching in 2019. Between 2019 and 2021, restoration experiments were conducted on 12 ponds across Martinique, Guadeloupe, and Saint-Martin, laying the groundwork for a comprehensive technical manual.
Building on this success, REMA II was introduced in January 2024 with a three-year scope. This new phase will focus on restoring and maintaining 80 ponds, both public and private, in Martinique and Guadeloupe. Additionally, it will address the management of invasive species and incorporate eDNA analysis to enhance conservation efforts. These small wetlands play a fundamental role in flood regulation, water storage, pollutant filtration, erosion control, and carbon absorption. They also provide refuges for biodiversity and contribute to the resilience of territories in the face of climate change.
(1, 2, 3)

Sri Lanka, particularly its low-lying coastal areas, faces recurring flooding challenges exacerbated by climate change, coastal erosion, and urbanization (1). Wetlands have emerged as crucial ecosystems in mitigating these risks, acting as natural sponges during heavy rainfall and releasing water gradually as flood levels subside (1). Beyond flood control, wetlands play a vital role in environmental quality. Their biodiversity helps filter pollutants and chemicals from the air and water, creating a healthier environment for both humans and wildlife (1). In 2018, Colombo was designated as a Global Wetland City under the Ramsar Convention, becoming the first and only capital city to receive this recognition (1). Recognizing the significance of wetlands as nature-based solutions, international institutions have prioritized their conservation through financing programs (1), and the city has developed projects to raise awareness and involve its citizens in their protection (1). These efforts have resulted in the creation of four wetland parks in the city, that comparing to a wetland, the wetland parks have more human intervention. Thus, they are focused on different topics and activities (2): Diyasaru Park, Beddagana Wetland Park (managed by the Urban Development Authority), Kotte Rampart Wetland Park (managed by the Urban Development Authority), and the Gothatuwa Wetland Park (managed by the Sri Lanka Land Development Corporation) (2). Gothatuwa Park is the newest wetland park and it is located in the flood-prone Gothatuwa neighbourhood (1). Inaugurated in 2024, It has a recreational focus, with trails for cyclists and hikers, and together with the other wetland complex, this park is designed to make the wetlands a cornerstone of local people's lives (1). Currently, environmental education activities are carried out in the park, focusing on managing aquatic invasive plants, tree planting and solid waste collection (3).

The Thalangama wetlands are part of a network of wetland ecosystems around Colombo city that spread over 20 km2 and provide critical life support to the city. These ecosystems keep people safe from floods, cool the air, filter polluted water, provide food and medicines, and fight climate change (10). These wetlands have become an environmental protection area and a biodiversity hotspot in a rapidly urbanising environment, as they host an array of plants and animals, including the endangered fishing cat and otter (5, 10). In 2007, Thalangama Lake and its surroundings were declared an Environmental Protection Area (EPA) under the National Environmental Act (4, 5). This protected area covers approximately 118 hectares (4) and includes two man-made reservoirs: Thalangama Tank (11 ha) and Averihena Tank (3.2 ha), located just 300 meters apart (5). The area hosts floating and rooted plants, scrublands, and trees that provide habitat to up to 100 species of migratory, resident, and endemic birds throughout the year. In addition, the area supports 30 species of dragonflies, 12 species of reptiles, 10 species of mammals, and 15 species of freshwater fish (1, 4). Since the lakes and their surroundings were declared an EPA, only limited uses are permitted, such as traditional fishing and rice cultivation (4, 5). The lakes are also important for floodwater retention and have high scenic and aesthetic value, attracting many visitors, and scientific and educational activities (5, 13).
However, due to the area's rapid urbanisation, land values have increased significantly, leading to excessive landfilling and the reclamation of paddy lands for housing. This is compounded by the indiscriminate disposal of garbage and construction waste and the spread of invasive species (5). These challenges have also led to the engagement of surrounding communities in managing and maintaining it (11).

The Waliwa project, launched in 2017 by the municipality of Sainte-Luce, is a collaborative effort dedicated to restoring marine biodiversity, enhancing the ecological balance of the bay area, revitalizing the local ecosystem and supporting sustainable economic activities. By focusing on marine biodiversity conservation, Waliwa addresses several critical environmental challenges. The project helps mitigate coastline erosion, support the blue economy through artisanal fishing and tourism, and foster an environmentally friendly culture among the local community.
So far, the Waliwa project has implemented three initiatives: it restored the Gros Raisin backshore to address erosion and provide nesting sea turtles with protected space (Ref 4). The project also intervened to restore the Pont Café pond, which was covered in Salvinia Molesta, preventing the intake of oxygen and hampering its role as a water filter, habitat for species and flood regulator .
Furthermore, the project has conducted studies and raised awareness about the challenges posed by wastewater management on the health of municipal water bodies. Through these efforts, Waliwa is working to create a more sustainable and resilient marine environment for future generations. (Ref 4, 5, 6; 12)

Booterstown Marsh, the only remaining saltmarsh on the south shore of Dublin Bay, plays a crucial role in the Dublin Bay Protection Plan. As part of South Dublin Bay's protected landscape, this unique 4.3-hectare brackish water marsh provides vital environmental and educational value within an urban setting. It supports three key habitats, ranging from freshwater to saltwater, creating essential feeding and roosting grounds for an array of migratory birds. The marsh attracts numerous bird species, including Moorhen, Reed Bunting, Sedge Warbler, Teal, Snipe, Lapwing, Oystercatcher, Redshank, Dunlin, and Brent Geese, establishing it as the only bird sanctuary in South Dublin Bay.
Booterstown Marsh’s ecological significance is underscored by its inclusion in the Dún Laoghaire-Rathdown County Council’s Biodiversity Action Plan 2021-2025: Nature Recovery, Restoration & Reconnection. Managed by the Biodiversity Section of the council, this initiative focuses on protecting and enhancing Booterstown Marsh as part of a broader effort to restore natural habitats across the area. The council’s project addresses key factors in biodiversity loss—such as land use pressures, climate change, and invasive species—by implementing an annual monitoring program to prevent deterioration of critical EU Annex habitats and species.
An Taisce, a local NGO has managed the marsh reserve since the 1970s, dedicating efforts to conservation and public education. This habitat, along with other local ecosystems like the wetlands at Ballycorus and woodlands at Loughlinstown, serves as an essential natural defense against climate change, removing carbon dioxide from the atmosphere and helping stabilize local landscapes by slowing floodwaters in catchment areas.(1-6)

In Berlin, at the palace park and garden Charlottenburg, approx. 40 to 70 horned Gotland sheep are used to maintain the grass fields and meadows. The project is part of a garden and landscape conservation programme that is to be seen as a contribution to practical nature conservation by the Prussian Palaces and Gardens Foundation Berlin-Brandenburg, which manages the park. From May to November, the sheep are grazing on the palace property, whereby the exact length of time the sheep are kept and the duration of the project depend largely on the developing weather conditions. This is because prolonged drought significantly reduces the growth of the grasses. (Ref. 1)
The garden had already been grazed earlier in its history, but no longer in the post-war period. The garden was created by Electress Sophie Charlotte in 1695. (Ref. 3) Since 2018, sheep can be found again in the park space where they graze on extensive meadows with groups of chestnut, lime, maple, oak, beech and solitary trees. At the beginning of May, they move into their first station there, usually the meadow in front of the late baroque-classical Belvedere tea house. Once this has been grazed, they move on to the next meadow; with an area of 55 hectares, there is plenty of pasture. (Ref. 4)
Sheep from his flock also graze on the green flat roof of the Max-Schmeling-Halle in Pankow, the palace garden of Sanssouci and other public and private patches of land around Berlin. Reasons to use sheep over machinery for the maintenance of the park space are monetary and a reduce loss of biodiversity. Sheep are cheaper compared to machinery, the needed labour and wear, and also don't kill insects living in the fields as machinery does. Furthermore, the sheep dung fertilises the grass area, sheep limit the spread of invasive plants and are more gentle to the soil. At the same time, palace visitors enjoy observing the sheep and can learn about them in guided tours. (Ref. 4; Ref. 6)

The beach of Vétiver, located in the municipality of Case-Pilote, is one of the most important nesting sites for the critically endangered hawksbill turtle (Eretmochelys imbricata) in Martinique. It is also a nesting ground for the green sea turtle (Chelonia mydas), another endangered species. As one of the last minimally urbanized beaches in the North Caribbean of Martinique, the site plays a vital role in the conservation of these species. In addition, fishing restrictions in the area significantly reduce the risk of turtle mortality caused by accidental capture in fishing gear, which is the leading cause of human-related sea turtle deaths in the Antilles.
However, the site faces several stressors that hinder successful nesting. The surrounding vegetation is severely degraded due to invasive alien species, and much of the shrub and tree cover has disappeared from the backshore, where turtles prefer to nest. Without adequate vegetation, hatchlings are left exposed to the heat. Additionally, the beach is frequently disturbed by local residents and visitors for recreational activities. With no designated parking area, cars often park directly on the beach, compacting the soil and further limiting the chances for vegetation to recover or turtles to dig nests. This compaction forces turtles to lay their eggs closer to the shoreline, increasing the risk of nests being washed away by heavy swells.
In 2022, the non-profit organization "Asso-mer" and its partners launched the Véti’Vert project on a previously neglected public green space. Through environmental restoration efforts, they created a nesting enclosure on the backshore to mitigate these stressors and improve the conditions for sea turtle nesting. The project also engaged with local residents to increase the chances of success (Refs 1-3).

The initiative focuses on the creation and implementation of a management plan for the Natura 2000 areas of Ciurbesti Lake and Fânațele Bârca to protect their biodiversity and promote sustainable tourism and land use. These areas were designated as part of the Natura 2000 network in 2016, but until recently, lacked a formal management plan. In 2019, the environmental group "Asociaţia Scutierii Naturii Bacău," in partnership with the Environmental Protection Agency of Iași (APM Iași), secured EU funding to develop the plan. While the plan was being developed, minimal regulations were established in 2022 to ensure interim protection.
The finalized management plan was released in 2024. It assessed species and habitats of European, national, and community importance, identifying 18 bird species, 3 plant species, 1 mammal species, and 4 key habitats. The plan also identified environmental pressures and set objectives and actions to ensure the conservation of this biodiversity. Before the plan's completion, two rounds of public consultations were held, involving a broad range of stakeholders, including surrounding municipalities, private landowners, public administrators, and local community representatives, to define optimal management practices.
The plan mandates continuous monitoring and reporting on the state of species and habitats. It also includes specific conservation measures, such as the partial reconstruction of endangered habitats, meetings with local land users to restrict harmful activities, public awareness campaigns, and regular monitoring. Additionally, it emphasizes the sustainable use of the area, including tourism. The creation of the plan was financed with EU funds totaling €1,036,014.27, and the projected cost for its implementation is €259,627.99. (1-5)

"Urban Natural Area Ciric" is an initiative aimed at designating the forest and lakes of the Ciric area, located on the outskirts of the city of Iași, as an Urban Natural Area. To achieve this goal, the initiating organizations—NGO Civica and the Ornithological Association of Iași (SOR)—have developed a comprehensive report focused on the Ciric natural area, which monitors species and habitats while identifying pressure points on biodiversity and necessary conservation actions, as well as the benefits these areas provide.
In the Ciric area, various flora and fauna species have been identified, with some holding high protection status (14 bird species) or being of community importance and conservation interest. However, this ecological richness faces threats, as factors such as rapid urbanization, water pollution, and waste disposal have been identified as significant risks to the ecosystems.
In response to these challenges, the NGO aims to collaborate with the municipality to create protective municipal laws that will not only recognize the area as an Urban Natural Area but also ensure its inclusion in development plans. This partnership seeks to establish regulatory measures and strategies that will safeguard and enhance the biodiversity and ecosystems of Ciric. Additionally, the organizations have highlighted the social and physical benefits of the area for residents, including flood regulation and prevention, pest control, provision of clean air, and recreational and scientific opportunities.
To further raise support and awareness for their efforts, SOR and Civica conduct guided tours, educational workshops, and photographic exhibitions. They have also set up two informational panels in the area that highlight the biodiversity of Ciric. Furthermore, the two NGOs have partnered with regional organizations to create the "Rețeaua națională de arii naturale urbane" (The National Network of Urban Natural Areas) and have received funding from the EEA Grants. (1-8)

This initiative focused on creating a management plan for the Uricani forest, a protected area located near Iasi. Designated as both a nature reserve and a Natura 2000 site, the forest is crucial for its "Dacia oak & hornbeam forests" habitat and the presence of the stag beetle, the largest beetle in Romania and Europe.
Despite existing nature protection designations, the environmental NGO "Asociația Ecoturistică Prietenii Pădurii Bălțătești" recognized the need for an updated management plan. With European funding, the NGO developed a model plan for protected areas in Neamt and Iasi counties, including Uricani forest.
The NGO conducted monitoring activities in cooperation with forestry directorates to assess habitat conditions and stag beetle populations. The goal was to identify risks and requirements for species conservation and design appropriate management actions. Additionally, the organization aimed to promote the area's tourism potential and conduct awareness-raising activities with local communities and schools.
The completed management plan, developed through public consultation and approved by the Romanian environmental ministry, included measures for natural habitat regeneration, ensuring suitable conditions for the stag beetle, addressing illegal logging, pasturing, and waste disposal, and establishing information points and educational activities for the community. (1-7)