Policy Brief - Contributions to the conservation of the European Eel (Anguilla Anguilla) and Management of Freshwater Ecosystems in Madeira

MARE is pleased to announce the publication of a new Policy Brief entitled ‘Contributions to the Conservation of the European Eel (Anguilla anguilla) and Management of Freshwater Ecosystems in Madeira’, which presents a critical analysis of the challenges and solutions for the preservation of aquatic biodiversity in the Madeira archipelago. 

This Policy Brief is the result of a collaboration between researchers Inês Órfão, Patrício Ramalhosa, Soledad Álvarez, Filipe Ribeiro, Ricardo Rocha, Isabel Domingos and João Canning-Clode, based on four scientific publications.

Madeira's freshwater ecosystems, which are notoriously vulnerable and poorly studied, are fundamental to the conservation of this species. The streams, interconnected by levadas and crossed by weirs, have relatively pristine sections, but face serious challenges due to habitat degradation, fishing pressure and obstacles that hinder eel migration. The introduction of invasive species, such as Gambusia holbroki and the New Zealand pond snail (Potamopyrgus antipodarum), further exacerbates the risks to local ecosystems.

Main consequences and recommendations

The concentration of eels in areas with greater human presence can directly affect their survival, reproductive success and physical condition. Increased competition for food and exposure to poor water quality are critical factors that require immediate intervention. Invasive species such as Gambusia and the New Zealand pond snail compromise local biodiversity and the ecological quality of the water.

Based on the results of the study, the authors of the Policy Brief propose three key recommendations to mitigate negative impacts and ensure the conservation of the European eel:

1) Strengthen eel management mechanisms in rivers by developing a management plan adapted to regional realities, including mechanisms for regulating and monitoring activities that may affect the viability of the European eel and the integrity of aquatic habitats;

2) Monitor and prevent the introduction of non-indigenous species: create protocols for the detection and control of non-indigenous species, such as gambusia and New Zealand pond snails, and assess the impact of these species on Madeira's freshwater ecosystems;

3) Promote the resilience of natural ecosystems by comprehensively characterising Madeira's rivers and identifying priority areas for preservation and restoration actions, including the removal of obstacles and the creation of passages to facilitate eel migration.

This Policy Brief is an important contribution to the development of management and conservation strategies for the archipelago's freshwater ecosystems, given Madeira's importance in the global effort to preserve the European eel.

To view the Policy Brief, click HERE

Written by Patrícia Carvalho