PARAPEZ II - Evaluation of the transmission of parasitism from farmed to wild fish species.
Pleamar program
Description
Fish species farmed in the open ocean, such as sea bream or sea bass, and those in wildlife, can share parasites. This is due to the fact that the nets that make up the cages are not watertight and, therefore, there is direct contact between them. In addition, seawater acts as a vehicle for many parasites. Therefore, both populations help to complete their biological cycle. The project, a continuation of the PARAPEZ project, beneficiary of the 2018 call of the Pleamar Programme, aims to reduce the transfer of parasites from fish species reared in cages in the open sea (Valencian Community and Canary Islands) to wild fish populations.
To carry out the project, three types of activities are proposed that are related to each other. First of all, it is necessary to know which wild species live around the cages and come into contact with those that live in captivity. To do this, a photo trapping system, designed in the first edition of the project, will be used at different depths, with which the fauna of the area will be known. Subsequently, fish will be caught inside and outside the nets for sampling and subsequent identification of parasites. A representative sample of individuals will be taken for subsequent necropsy (with inspection of gills, digestive system, among others) and parasitic identification. With the results, by farm and intra-cage and extra-cage parasites, possible interactions will be established and potential risks for wildlife infection will be identified.
The secondary objectives to be pursued are, on the one hand, the development of recommendations for farms, so as to minimise the risk of infection to wild fish and reduce the spread of parasitic forms. On the other hand, the training of the staff of the participating aquaculture farms on the risks associated with fish parasites and the preventive and control measures applicable at farm level.
Line of action:
Marine ecosystemsStatus:
FinalizadoExecution date:
2019General:
Reduce the transfer of parasites from wild fish populations from fish reared in cages in the open ocean.
Specific:
1. Know the species of wild fish associated with aquaculture farms.
2. To know the parasites shared by wild species associated with aquaculture farms and the species raised in them.
3. To study parasitic interactions and potential hazards to wildlife from the transmission of parasites from animals raised in cages in the open sea.
4. Develop recommendations to minimize the impact of aquaculture farms on wildlife.
5. Disseminate the results of the project.
ACTIVITY 0 Management, coordination and administration
ACTIVITY 0.1 Technical management of the quality, sustainability and occupational safety of the project
ACTIVITY 1 Population study of the fauna around the cages and measurement of environmental parameters
ACTIVITY 2 Parasitological study of cultivated and wild species
ACTION 2.1 Parasitological study of cultivated and wild species
ACTION 2.2 Study of individuals of wild species present inside nurseries.
ACTIVITY 3 Study of parasitic interactions and potential hazards to wildlife
ACTIVITY 4 Recommendations to minimize the risk of spread of pathogens.
ACTION 4.1 Recommendations to minimise the risk of spread of pathogens.
ACTION 4.2 Training of farm staff on the dangers associated with parasites in fish and means of prevention.
ACTIVITY 5 Actions to disseminate the results of the project
The project, developed in eight different aquaculture facilities (four in the Canary Islands and four in the Valencian Community), has made it possible to expand knowledge about the interactions of parasites between species raised in aquaculture farms in the open sea and the wild species present around them. The results include:
Photo trapping system:
In order to evaluate the synanthropic species around the aquaculture cages, a photo-trapping system was designed and installed outside them for the capture of periodic images. This system consisted of the installation of three underwater cameras at different heights (2.5, 10 and 15 m), which took images every 20 seconds. In total, approximately 27,000 underwater images were evaluated, from which it was possible to study the presence of species in the vicinity of the farms. The presence of bogas, pomfrets, breams, alachas, horse mackerel … as well as predators such as barracudas, dolphins or yellowtails.
Analysis of aquaculture and synanthropic species
More than 500 fish have been sampled throughout the project, from aquaculture farms – sea bream (Sparus aurata), sea bass (Dicentrarchus labrax) and sea bass (Argyrosomus regius) – and from synanthropic species caught in the participating farms. Among these synanthropic species are alachas, jacks, snappers, sea breams, bogas, mullets… Samples were taken from all individuals, both from the intestinal bundle and from the gill arches, for subsequent analysis in search of parasites and their identification.
Specifically, 19 species of monogenids have been identified and in extracage species five species of crustaceans, four species of nematodes (Cucullanus spp. Anisakis Spp. Philometra spp. and Hysterothylacium spp.) and acanthocephalic. Intracage species are characterized by a higher percentage of parasitization compared to wild species, however, the latter have a greater variety of parasites, per specimen and population.
Regarding the study of parasitic interactions and potential dangers to wildlife, monogenids of the species Diplectanum spp. have been observed in wild and farmed sea bass. A report was prepared for each farm with the results of the study on their premises and recommendations on preventive measures to be adopted in order to minimise the risk of parasite transmission between wild and farmed species, and vice versa.
Population study of pen shell (Pinna nobilis)
During the visits, visual inspections of the floating structures of aquaculture farms were carried out in search of populations or individuals of pen shell (Pinna nobilis), which were negative. Worker surveys were also carried out to assess the presence or absence of pen shell individuals in the vicinity of farms or attached to floating structures. Most workers affirmed their presence, but it was not feasible to confirm individuals, since they can be easily confused with other species such as Pinna rudis.
Dissemination of the project
The project included the organisation of training workshops for aquaculture professionals, in order to convey the results of the project and to inform about the epidemiological situation of the farmed species and the environment surrounding them. The dissemination of the project was channelled through the beneficiary’s website, newsletter and social networks, as well as through scientific-technical conferences for the dissemination of the project results.
PARAPEZ II - Evaluation of the transmission of parasitism from farmed to wild fish species.
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