Regional patterns in prevalence of principal external diseases of dab Limanda limanda in the North Sea and adjacent areas 1992-1997

[摘要] ABSTRACT: The prevalence and spatial distribution of major diseases of dab Limanda limanda in the North Sea and adjacent areas were studied in the summers 1992 to 1997. Areas covered were the North Sea, Irish Sea, northern and northeastern BritishWaters and the English Channel. The diseases studied were lymphocystis, epidermal hyperplasia/papilloma and skin ulceration. To standardise data, results were analysed for females >15 cm (>3 yr old). Data were subjected to median polish, andadditive, extended and additive plus multiplicative models were applied to best account for effects of region and year. Annual differences in disease prevalence were low whilst differences between areas were pronounced. For lymphocystis higher prevalencewas observed in the northwestern sector of the North Sea, at the northern tip of Scotland and in an area south of Iceland. Prevalence was low in the Irish Sea, the English Channel and the southern North Sea, and intermediate in the German Bight. Forepidermal hyperplasia/papilloma, levels were low at Icelandic stations, in the northern Irish Sea, in the southern North Sea and the English Channel, whilst levels were high in the northwestern part of the North Sea and the German Bight. Elevated levelsof skin ulceration were found on the Dogger, at 1 station in the Irish Sea (off Sellafield) and at 1 station to the south of Iceland. Lower levels were detected west of Iceland. Prevalence in all other areas was intermediate. It is concluded that adetailed analysis of available data on disease prevalence and putative causative factors is desirable and, given the good availability of data, would be a promising step forward toward elucidating possible cause and effect relationships between diseasesand anthropogenic factors.

[学科分类] 生物科学（综合）

[关键词] Lymphocystis;Skin ulceration;Epidermal papilloma/hyperplasia;Dab;Limanda limanda;Regional distribution;Prevalence rates;North Sea and adjacent areas