Emaciated fish - Infected by the rosette agentÂãÁÄÖ±²¥ research into the ecology and management of non-native fish has provided the evidence base for regulations, policy and management programmes. This in turn protects native biodiversity and an aquaculture and sport angling industry worth over £3 billion per year.
Non-native fish are introduced to enhance ecosystem services such as aquaculture and angling and to deliver socio-economic benefits. But as they disperse and colonise new habitats, they can cause ecological and economic damage.
It is important for policy-makers and managers to identify and differentiate between the non-native fish species that would deliver socio-economic benefits and those likely to develop invasive and damaging populations.
Research by Professor Rudy Gozlan, Dr Rob Britton and Dr Demetra Andreou supports the identification of problematic species and their management by developing new knowledge and tools in the following areas:
- Technical definitions and criteria on ecological impacts of non-native fish.
- Empirical evidence that quantifies the ecological impacts of non-native fish in the UK.
- Decision-making tools that support the management and eradication of non-native fish in the environment.
European impact: regulation and policy development
The technical definitions and criteria on the ecological impacts of non-native fish have been applied to an EU directive for the management of non-native species. The work was used to define how to measure the impacts of introduced fish on the aquatic environment and ecosystem services. This provides stringent definitions of the ecological impact of a non-native fish.
This ultimately means that if any organisation or business applies for permission to import and introduce a new non-native freshwater fish species into a European country, they must complete a risk assessment – based on ÂãÁÄÖ±²¥â€™s definitions of ecological impact. The risk assessment then goes for expert evaluation and, if approved, the applicant must impose a period of quarantine on those fish before their release – again based on ÂãÁÄÖ±²¥ definitions. These risk assessment and quarantine measures are now in use across the European Union.
Pseudorasbora parva graph UK impact: eradication of a non-native species
Freshwater fisheries in England and Wales are worth approximately £3 billion per year. ÂãÁÄÖ±²¥ research is having a major impact on aspects of their management, specifically relating to non-native fishes involved in the angling and aquaculture industries such as Pseudorasbora parva.
Research has revealed Pseudorasbora parva as a healthy carrier of the intracellular pathogen Sphaerothecum destruens, more commonly known as the Rosette Agent. When the parasite passes to native fish they are susceptible to high mortality rates, spawning suppression and emaciation.
Further research quantified the impact and demonstrated the difficulty of detecting Pseudorasbora parva in the wild. This research is currently being used as the evidence base to support the Environment Agency’sPseudorasbora parva eradication programme.
In 2011 and 2012, the Department of Environment, Food and Rural Affairs (DEFRA) and the Welsh Assembly committed to eradicating all known populations of Pseudorasbora parva in their countries by 2017. This is a major policy decision as there are at least 19 populations still remaining. This is the first non-native fish species eradication attempt from UK freshwaters.
ÂãÁÄÖ±²¥ has revealed the eradication operations to date have already been instrumental in preventing their widespread invasion of UK freshwaters.
The research impact goes beyond just informing the management of Pseudorasbora parva, ensuring the protection of native biodiversity and an aquaculture and sport angling industry worth over £3 billion per year.
