Diseases of eels in an international perspective: Workshop on Eel Diseases at the 15th International Conference on Diseases of Fish and Shellfish, Split, Croatia, 2011

In recent years, significant attention has been assigned to the decline in the wild freshwater eel stocks worldwide. Possible causative factors include fisheries (overfishing), habitat loss, migration barriers, and chemical pollution, and/or a combination of these factors. Infectious diseases however, as associated causal factors, have received little attention to date. In eel farming systems, diseases are lethal under certain stressful conditions and high stocking densities. Similar environmental or infectious disease conditions may also negatively affectwild eel populations. Eel stocks also declined in Japan, where eel culture began in 1879 in Fukagawa, Tokyo. Farmed eel gradually decreased from 40, 000 to 20, 000 tons in 1999 to 2008, whereas eel imports increased year by year from 1995. Following traditional Japanese eel culture, where open ponds were frequently used, from 1972 pond culture inside a green house was introduced, at a water temperature of about 28°C . This change has been considered a main trigger to the appearance of new diseases. To address these issues of concern, a workshop on “Eel Diseases” was organized at the 2011 EAFP Conference, at Split, Croatia. In this workshop, with approximately 40 participants from various countries, field observations and research findings on eel pathogens and diseases were presented, with the aim to summarize the information on the status of known and emerging pathogens and novel techniques in diagnostics and therapy, and build a network on eel disease experts.