On the occurrence of lymphocystis, with notes on other pathological conditions, in the flatfish stocks of the north-east Irish Sea

Shelton, Richard; Wilson, K. W.

doi:10.1016/0044-8486(73)90171-3

Cited by 30 publications

(19 citation statements)

References 6 publications

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“…In flounder from the marine and brackish regions of the Elbe estuary, lymphocystis was found at lower frequencies in comparison with the Irish Sea (Shelton & Wilson, 1973), Gullmarsfjord (M611er, 1979), Oresund (Nordenberg, 1962), eastern Baltic Sea (Vitinsh & Baranova, 1976), and Irish coastal waters (McArdle et al, 1982), but at higher prevalences than in Kiel Fjord (M611er, 1974). No sufficient data are available for other flounder diseases.…”

Section: Other Fish Speciesmentioning

confidence: 99%

Dynamics of fish diseases in the lower Elbe River

Möller

1984

Helgolander Meeresunters

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As part of a survey on population dynamics and ecology of fishes in the Elbe River, seasonal and regional fluctuations of external fish diseases were studied from the open North Sea to Hamburg in 1981Hamburg in -1982. Clinical signs of 11 different diseases, several of them not being recorded before, were noted in 22 fish species. Averaged over all samples, the total disease prevalence was below 1% in 16 species. Highest prevalences were found in smelt (12.7 %), eel (9.2 %), and flounder (5.5 %). The frequency of most diseases increased in larger (older) fish. High prevalences of skeletal abnormalities in cod could be related to abnormal migration habits of diseased fish. Spawning papillomatosis, skin ulceration, and fin rot in smelt occurred predominantly during the spawning season. Most diseases observed occurred at relatively high prevalences in the central Elbe estuary between Cuxhaven and Brunsbiittel. This is most obvious for lymphocystis, fin rot, skin ulceration, and bleaching syndrome in flounder, but such a tendency also seems to occur in cauliflower disease of eel, as well as spawning papillomatosis and pharyngeal granuloma in smelt. This area is less heavily polluted and less frequently affected by oxygen deficiency than the area upstream of Gliickstadt, where diseases in general occurred at lower frequencies. Therefore, it is concluded that neither pollution nor lack of oxygen are the main triggers for the outbreak of diseases in Elbe fish. It is supposed that large tidal fluctuations of salinity are a major stress factor for fish in the estuary between Cuxhaven and Brunsbfittel, Flounder from this area usually are in a relatively bad nutritional state. Their condition factor increases significantly towards Hamburg, while their disease prevalence decreases in the same direction.

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Section: Other Fish Speciesmentioning

confidence: 99%

Dynamics of fish diseases in the lower Elbe River

Möller

1984

Helgolander Meeresunters

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“…The present study concentrated on European flounder Platichthys flesus, which are restricted to coastal waters where pollution loads are highest. Earlier studies of this species in the North Sea and the Irish Sea were unable to produce evidence ior a direct efiecr of pollution on disease prevalences (Perkins et al 1972, Shelton & Wilson 1973, Newel1 et al 1979, McArdle et al 1982, Bucke et al 1983a, b, Reiersen & Fugelli 1984. However, these negative findings may be partly attributable to methodological shortcomings (Vethaak & ap Rheinallt 1992).…”

Section: Introductionmentioning

confidence: 99%

Diseases of flounder Platichthys flesus in Dutch coastal and estuarine waters, with particular reference to environmental stress factors. I. Epizootiology of gross lesions

Ad¹,

Jg²

1996

Dis. Aquat. Org.

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Diseases of flounderFlounder were found to be affected by the viral skin disease lymphocystis and by skin ulcers probably of bacterial origin. Overall prevalences of these 2 diseases in fish 2 2 yr old were 14.3%r and 2.8% respectively. Also notable was t h e presence of neoplastic nodules in the livers of 1.0% of the population, prevalences rising steeply with a g e and locally attaining values of up to 3 0 % in 6+ yr old fish. Most of the samples were collected in September when flounder are resident in inshore feeding arcas. Using data from 9 sites, spatial and temporal (year-to-year) variation in disease occurrence was analysed statistically using log-linear models which incorporated possible effects of length, a g e and sex. Year-toyear variation showed little correspondence among the 3 diseases, but their spatial distributions showed striking similarities. Lymphocystis and skin ulcers were associated in individual fish. The observed variation in disease prevalence showed no significant correlation with condition factor of the fish or with concentrations of contaminants in sediments or tissues. However, disease preval e n c e~ at different sites showed a strong positive correlation with fishing activity (possibly indicating an effect of damage by fishing gear) and appeared also to be positively related to salinity. When only strictly marine sites were considered, a relationship with pollution could not be ruled out. Additional data collected in February-April at offshore sites indicated that disease preval e n c e~ were generally higher at this time of the year, which corresponds to the spawning period of the populations studied. This trend was particularly pronounced for liver neoplasms, and might be partly related to a low condition factor resulting from spawning activities. In view of the different aetiologies of the 3 diseases, the similarities in spatial patterns indicate the existence of 1 general underlying mechanism of disease causation, perhaps acting through immunosuppressive effects. However, age-related migration appeared to explaln some aspects of the spatial pattern of liver neoplasms, whereas it was less important in the case of epidermal diseases, which develop more rapidly. On the basis of the findings of this study, the possible contribution of pollution to disease prevalence cannot be adequately assessed due to the interfering effects of other factors (salinity, fishing activity, migration and spawning). Disease causation appears to be con~plex, and it may be that effects of pollution interact with those of other factors to produce observed, spatial patterns.

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“…Perkins et al (1972) suggested that PCBs may have been responsible for lymphocystis in adults of two species of flatfishes, common hosts for lymphocystis in areas more temperate than the Gulf of Mexico, in the Irish Sea at the same time that young individuals in an uncontaminated area did not develop the disease; however, Shelton and Wilson (1973) considered hydrographic conditions such as low salinity to be a better explanation. Wolthaus (1984) reported infections in the dab, Limanda limanda, a flatfish in the southern North Sea, to be associated with acid iron waste from titanium dioxide production, regardless of season, but others (Möller 1985) questioned the validity of that cause.…”

Section: Viralmentioning

confidence: 99%