Targeting fish parasites for a healthier aquaculture industry
EU-funded marine scientists are fighting fish parasites in farmed fish by developing new strategies and technologies to prevent their spread and ensure high-quality seafood for consumers.
© auremar #163076635, source: fotolia.com, 2018
In Europe alone, fish farming generates EUR 3 billion per year and employs an estimated 80 000 people. But, parasites in farmed fish are causing great losses just one, the sea louse, costs the EU EUR 300 million annually.
Parasites and related infections can cause significant damage to farmed fish and result in poor growth and high mortality rates, which can seriously hamper production and revenues.
In response, the EU-funded ParaFishControl project is developing new ways of combating these parasites. The projects researchers anticipate that the resulting anti-parasite outcomes could lead to an increase in sustainability and competitiveness of the European aquaculture industry.
Parasites are well-adapted to survival, and project coordinator Ariadna Sitjà-Bobadilla of the Consejo Superior de Investigaciones Cientificas in Spain warns that there is no simple solution to the problem.
The project is tackling this by researching vaccines and anti-parasitic treatments, as well as boosting fish immunity and developing new diagnostic tools. A combination of these steps should enable policymakers and fish farmers to reduce parasites and their impact.
The best strategy for controlling pathogens is not using a single bullet, she says. Its trying an array of different ways of controlling the disease. The idea is that we have different options to mitigate their impact because we cannot kill every parasite.
Testing times for candidates
Several tests to determine what type of parasite is present have been produced by the team, with the goal of standardising parasite identification techniques throughout Europe.
To date, 200 potential ingredients for anti-parasite medications have been identified by the researchers and several have already been trialled. Preliminary results suggest that some of these successfully inhibit parasite development.
New molecular techniques are being tested to determine how effective they are at identifying antigens, tiny proteins that spark immune response. Antigen identification is one of the first steps along the road to vaccine development, and the researchers plan to find candidate vaccines one of the initial stages in vaccine creation before the projects end. In fact, an effective antigen has already been found for one parasite species.
Complicated life cycles
However, there are scientific challenges associated with anti-parasitic vaccines production. Producing vaccines against parasites is very tricky. There is currently no commercial vaccine at all for any fish parasite in the world, says Sitjà-Bobadilla.
One of the problems is that parasites have complicated life cycles, often occupying more than one host. ParaFishControl is mapping out the life histories of lesser-known species, enabling scientists to develop effective treatments in the future.
To educate fish producers, veterinary practitioners and other aquaculture professionals on best practices for parasite diagnosis and control, the project will publish booklets and guidelines and will organise workshops an two dedicated international training courses for MS students, PhD students, and postdoctoral fellows on fish parasite diagnosis (see the website for more details).
Another important goal of the project is to facilitate effective knowledge exchange between academia, industrial companies and fish farmer associations. An industry forum has been established to mobilise these stakeholders in a sector-wide effort to combat and manage fish parasitic diseases with novel approaches and solutions.
A final international conference will be organised at the end of the project to present its achievements to the most important stakeholders from the EU aquaculture community, decision-makers and research institutes.