Guest Article - 20 years of Lamprey Management in Portugal: replicating a success story

The Iberian Peninsula was one of the most important refugia in the European subcontinent during the Pleistocene glaciations, acting intermittently as a refugium and a source for postglacial expansion. This made the Iberian Peninsula an area of particular importance for the evolution and speciation of lamprey species, with implications on genetic diversity and overall long-term conservation. Six lamprey species occur in the Iberian Peninsula: Petromyzon marinus L., Lampetra fluviatilis L., L. planeri Bloch 1784, L. lusitanica Mateus, Alves, Quintella & Almeida 2013,  L. auremensis Mateus, Alves, Quintella & Almeida 2013 and L. alavariensis Mateus, Alves, Quintella & Almeida 2013 (Fig.1), the last three being Portuguese endemisms. 


Over the last 30 years, a severe decline was observed in lamprey populations, with obstacles to migration (dams and weirs) being among the major causes for such decline, as an estimated 80% loss of accessible habitat in the Iberian Peninsula has occurred (Fig.2). The life cycle of these species differs between anadromous and freshwater residents. The project EVOLAMP (“Genomic footprints of the evolution of alternative life histories in lampreys”; PTDC/BIA-EVL/30695/2017) intends to study the molecular basis of distinct life histories, through the identification of genes related to marine and freshwater adaptations, and their expression along the life cycle and in distinct contexts. This investigation is important to understand the evolution of these species, as well as their adaptive ecological capacities to different environments in a conservation perspective.

            For the last 20 years, researchers from the University of Évora / MARE have been focused on the management and conservation of diadromous fish in Mondego river, especially lampreys, with particular attention on the biology, ecology, and identification of obstacles to migration. Habitat rehabilitation actions started in 2011, with the aim of re-establishing river connectivity, while ensuring the compatibility of river uses and the engagement of all stakeholders ( 

The construction of a new vertical-slot fish pass at the Coimbra Dam, by the Portuguese Environmental Agency (APA), increased the available habitat for anadromous species in 51 km (340% increase), and almost 62 000 lampreys were counted using the fish pass between 2011-2018. Efforts for the reestablishment of longitudinal connectivity in Mondego river continued through the construction of five nature-like fish passes in smaller weirs, four of which upstream of the Coimbra Dam, and the additional removal of a weir. By 2018, electrofishing surveys revealed larvae abundance in the upstream stretches increased 45-fold since 2011 (Fig. 3). 


In a pilot approach towards participated fisheries management, these data are presented every year, since 2012, in annual meetings held with commercial fishermen and fisheries administration, accomplishing stakeholders’ involvement, and leading to yearly adjustment to fisheries legislation. In this context, changes such as the fishing season reduction and the implementation of a mid-term closure during the peak of the migration season were established to benefit lamprey recovery since 2013, together with fisheries monitoring and the implementation of regular meetings between authorities, fishermen and scientists to discuss the restrictions that should be adopted in the following season. After several years of working with these communities, major progress was achieved, with fishermen from other river basins demanding for similar investments and implementation of measures alike.

After the success in the Mondego river basin, other projects have emerged with the aim of improving the management and conservation of migratory fish in Portugal. Projects such as SalmonLink (“Contribution of scientists and fishermen for the conservation and participated management of Atlantic salmon in Portugal”), AN@DROMOS.PT (“Operational Plan for the Monitoring and Management of Anadromous Fish in Portugal”)” and LIFE Águeda (“Conservation and Management Actions for Migratory Fish in the Vouga River Basin (LIFE16 ENV/PT/000411)”), extended the conservation efforts to other river basins, aiming to replicate Mondego’s river basin exciting results. SalmonLink benefits from previously established networks and aims to apply some of these successful management approaches to another anadromous fish of conservation and cultural importance in our river basins, the Atlantic salmon. Through a partnership between scientists, commercial fishermen and anglers, this project will contribute to increase the knowledge about Portuguese salmon populations and propose suitable measures and regulations that can promote its sustainable management. AN@DROMOS.PT, with an intervention area extending to eight of the main Portuguese river basins, aims to implement a monitoring and management program directed to anadromous fisheries by establishing their population above Maximum Sustainable Yield levels. With a total investment of 3,3 M euros, LIFE Águeda will have a total of five fish passes built and three obsolete weirs completely or partially removed in the Vouga river basin in 2021, increasing connectivity by 34 km in rivers Águeda and Alfusqueiro. Sustainable fisheries management is another target sought by this project, engaging professional fishermen. Lampreys caught in the Mondego and Vouga river basins can now bear a label of origin (Fig. 4), in an effort towards market differentiation and wild fish valorization, and this initiative received high praises from fishermen, with communities from other regions asking for the same type of distinction for their lampreys. A follow-up monitoring program will provide new insight on the impact of the project actions and the strong component of public awareness and dissemination of results will further engage stakeholders and communities.

In total, the investment towards lamprey conservation in Portugal has been very high, either in the perspective of the scientific research and data collection, human resources and community engagement, or in terms of the financial investment, reaching ca. 10 M euros. This investment is paying off, as far as lamprey populations are concerned, as a visible lamprey recovery can be witnessed in the Mondego river basin, and more fishermen are getting involved and want to be a part of this integrative management approach.


P.R. Almeida1,2, B.R. Quintella1,3, C.S. Mateus1, S. Pedro1, I.C. Oliveira1, E. Pereira1, A.F. Belo1, C.M. Alexandre1

1 MARE – Marine and Environmental Sciences Centre, University of Évora, Évora, Portugal

2 Department of Biology, School of Sciences and Technology, University of Évora, Évora, Portugal

3 Department of Animal Biology, Faculty of Sciences, University of Lisbon, Lisbon, Portugal


Links to projects’ pages (please include as hyperlinks in the text):


LIFE Águeda:



Mateus, C. S., Rodríguez-Muñoz, R., Quintella, B. R., Alves, M. J., & Almeida, P. R. (2012). Lampreys of the Iberian Peninsula: distribution, population status and conservation. Endangered Species Research, 16(2), 183-198. DOI: 10.3354/esr00405 

Moser, M. L., Almeida, P. R., King, J. J., & Pereira, E. (2020).  Passage and freshwater habitat requirements of anadromous lampreys: Considerations for conservation and control. Journal of Great Lakes Research (in press), DOI: 10.1016/j.jglr.2020.07.011.