Preventing a LIONfish invasion in the MEDiterranean through early response and targeted REmoval (RELIONMED)

4.5 years (September 2017 – February 2022)

Funded by:
LIFE Programme – Nature and Biodiversity (European Commission)

Project partners:
University of Cyprus (Coordinator)
Marine & Environmental Research (MER) Lab Ltd (Scientific Coordinator)
Enalia Physis Environmental Research Centre
Department of Fisheries and Marine Research
Plymouth University

Project Description:
Biological pollution is one of the major threats to global biodiversity. Marine invasive species are particularly difficult to control due to a lack of barriers to their spread. One of the most ecologically harmful marine invasions to date is the rapidly expanding population of non-native lionfish (Pterois spp.) in the western Atlantic. These fish have had marked ecological impacts throughout the Caribbean and in some areas lionfish increases have coincided with significant regional declines in native fish species biomass. Lionfish are highly fecund; they mature within a year and then spawn every four days year-round. They can produce two million buoyant eggs per year and these develop into pelagic larvae that disperse widely on currents. The adults have anti-predatory venomous defences and an ability to prey upon a wide range of fish and invertebrates, a combination that makes lionfish rapacious invaders.

Lionfish (Pterois miles) are spreading in one of the fastest fish invasion ever reported in the Mediterranean Sea where they are disrupting ecosystems and have the potential to impact linked livelihoods. Evidence from the coasts of Cyprus indicated that Pterois miles has set off a new invasion, this time in the Mediterranean. Two decades after their first appearance in the Mediterranean, a specimen was caught off Lebanon in 2012 and in just four years, lionfish became established around Cyprus, Greece, Lebanon and Turkey. Clearly, current environmental conditions are now suitable for lionfish reproduction in the eastern Mediterranean. Continued warming of the Mediterranean basin increases the risk of a speedy invasion.

The EU-funded RELIONMED-LIFE project aimed to make Cyprus, due to its geographical position, the ‘first line of defence’ against the invasion of the lionfish in the Mediterranean. With the active involvement of the general public and local stakeholders, the project team tested the effectiveness of several actions to control lionfish diffusion in Cypriot Natura 2000 sites, Marine Protected Areas (MPAs) and diving sites (wrecks and artificial reefs).

The implemented actions included: the analyses of lionfish biology and distribution patterns; the formulation of a risk assessment analysis of lionfish to include this species in the list of Invasive Alien Species of Union concern (the Union list -EU Regulation 1143/2014); the development of an early detection system for lionfish with an online dedicated portal and a phone application; the training of SCUBA and free divers and the implementation of targeted removal events including competitions; the training and motivation of fishers; the promotion of new niche markets for lionfish commercialisation; and the development of a regional management plan.

Through the help of the RELIONMED team, stakeholders, divers, fishers, researchers, and local citizen scientists, the RELIONMED-LIFE project was a remarkable success. Specifically, through RELIONMED, we:

  • Monitored the Mediterranean distribution of lionfish. GIS maps were created that identified high risk areas where lionfish removal efforts should be concentrated. Removal sites were selected in two Natura 2000 sites: Cape Greco and Nisia, and Marine Protected Areas (MPAs) including dive sites such as wrecks and artificial reefs (i.e., Nemesis III, Liberty, Kyrenia – Ayia Napa and Zenobia).
  • Assessed the local biology of lionfish and their ecological and socio-economic impacts. Lionfish biological analyses were conducted using 268 lionfish samples collected from Cyprus showing that Mediterranean lionfish: (i) have an opportunistic diet, fast growth, high fecundity, early maturity, absence of predators naïve prey, and they mainly consume native fish species; (ii) spawn mainly during the warmest months (June – November) (iii) and are genetically diverse indicating large numbers were introduced through the Suez Canal.
  • Modelled the potential for lionfish to spread. Ecological knowledge was gained from tissue samples obtained from 56 lionfish individuals, DNA analysis was used to identify potential pathways of introduction and spread of the species through the Mediterranean.
  • Raised awareness of lionfish as an invasive but edible species. Surveys revealed an increase in the percentage (90% in 2017 and 99% in 2021) of stakeholders who were aware that the species can be consumed and an increase in the percentage of stakeholders who were willing to support lionfish management in Cyprus from 85% in 2017 to 89% in 2021.
  • Introduced lionfish to Cypriot markets. Lionfish was added to the Cypriot fish market in 2019, prior to this they were discarded by fishers, its retail price increased to 12-15 € per dish in Cypriot restaurants by 2021. At the end of the project 10% of seafood restaurants in Cyprus incorporated lionfish in their menus. The spines, rays, skin and tails of lionfish can be used to make jewellery, during the project over 100 jewellery sets were made and provided to dive shops to assess the marketability of the products.
  • Trained divers and fishers to monitor and remove lionfish. Physical removals via spearfishing and SCUBA gear were identified as the most effective removal method in the Mediterranean Sea. Through the supervision of RELIONMED Action Teams (RATs) a total of 4,767 lionfish were removed by volunteer SCUBA divers and free divers using a special lionfish removal toolkit.
  • Showed that spearfishing can keep lionfish densities below levels that cause ecosystem damage: where frequent lionfish removal activities were allowed there was a 64% decrease in lionfish numbers and a 250% decrease in lionfish biomass. Average lionfish size reduced from around 20 to 18 cm in length.
  • Built social capital in invasive species management. Citizen science schemes such as the MedMis lionfish portal where citizens can upload their sightings with a form and a photo were used, MER will continue to validate these sightings.
  • Proposed lionfish for inclusion in the list of invasive species that need management by all EU member states. EU Member States (e.g. Cyprus and Greece) are now under consultations to remove catch limits for lionfish and allow recreational fishers to catch as many lionfish as possible.
  • Supported collaboration between stakeholders in Mediterranean and western Atlantic countries with all partners committing to continue exchanging ideas and efforts for at least five years after the project.
  • Communicated our findings with
    • 13 scientific publications in peer-reviewed journals
    • 85 articles (at local and international websites and online newspapers) which were distributed in hundreds of others
    • 22 press releases
    • 11 television appearances
    • 5 radio appearances
    • 6 videos (produced by the RELIONMED team)
    • 40 participations in events & conferences
    • 13 posters and leaflets
We are proud for acting as the scientific coordinators of the project ensuring its success and global impact. Lessons learnt during the European RELIONMED project set the basis and provide tools that can be transferred and used to help lionfish management across the Mediterranean. We are grateful to all our partners, namely Department of Fisheries and Marine Research, University of Cyprus, Enalia Physis, and University of Plymouth for the dedication and support. We would also like to thank EU LIFE programme which financially supported our project.
In April 2022, we published a series of recommendations to enable communities and managers to minimise the impact of lionfish in the Mediterranean Sea.
This includes organising targeted culls and creating a supply chain between fishers, markets, businesses and consumers to make lionfish a component of the region’s fishing industry.


Check the Final Management Guide that was produced through the project here:
Integrated Management Guide for the Lionfish in the Mediterranean Sea

Visit RELIONMED’s website