OSPAR request on assessment of data of fish diseases

ICES undertook a trial assessment of fish health data for dab available in the ICES Data Centre to explore the

usefulness of a Fish Disease Index (FDI). Sufficient data were available to perform assessments for externally visible diseases and for macroscopic liver neoplasms in a number of ICES statistical rectangles. For externally visible diseases, 10 of the 14 ICES statistical rectangles assessed were characterized by a worsening of disease status, in either level (i.e., increased mean FDI for 2002–2007 as compared to mean FDI for 1992–2001), trend (significant pattern of increasing FDI values over the years 2002–2007), or both. For macroscopic liver neoplasms, only one rectangle showed an improvement in level of FDI.

The worsening of the disease status of dab in the majority of geographical areas assessed should be considered an alarm bell to stimulate more research on the identification of causes of this general phenomenon.

This trial application of a Fish Disease Index to the available fish health data clearly demonstrates the utility of this approach to assess fish health and to evaluate the impact of anthropogenic induced stresses on fish. There is

considerable value in national laboratories making their fish health data available to the ICES Data Centre so that the disease assessment can be expanded in the future. It is also clear that there are many opportunities to build upon this approach to using the fish health data. For example, more data on macroscopic liver neoplasms and liver pathology data would permit an assessment of the impact of various chemical contaminants on fish health. ICES encourages the continuation and expansion of fish health monitoring programmes, the submission of additional fish health data, and the further development of the FDI and other approaches to using the fish health data.