Interim Report of the Working Group on Pathology and Diseases of Marine Organisms (WGPDMO)

The ICES Working Group on Pathology and Diseases of Marine Organisms (WGPDMO) met on 14–18 February 2017 at the National Marine Fisheries Research Institute, in Gdynia, Poland. The meeting was chaired by Ryan Carnegie (USA) and attended by six participants, with seven ICES Member Countries represented.

The agenda included several topics related to diseases and pathology in wild and farmed fish and shellfish. The group produced a report on new disease trends in wild and farmed fish and shellfish in the ICES area based on national reports from fourteen member countries. Notable reports for wild fish included new observations of salmon gill poxvirus in eastern Canada after a single, initial observation in 2015; continued increase in the prevalence of Contracaecum osculatum in Polish waters; increase in the prevalence of Anisakis simplex in Barents Sea waters of Russia; and continued unexplained mortality in salmon in the Barents and Baltic Seas. Reports for farmed fish included detection of infectious pancreatic necrosis virus in salmon and sea trout from Latvia; expansion of the distribution of salmonid rickettsial septicaemia in western Canada, with observations also in Ireland; and increasing occurrence of cardiomyopathy syndrome in salmon in Ireland. Additionally, amoebic gill disease remains a challenge for Atlantic salmon culture in the ICES region.

New observations continued to be made of pathogens in cleaner lumpfish, including in Iceland viral haemorrhagic septicaemia virus, and in Ireland a ranavirus, Piscirickettsia salmonis, and Exophiala. Notable observations for shellfish included continued association of OsHV-1 μvars with mortality of young Pacific oyster in France, and expansion of their known distribution in England; continued detection of Vibrio aestuarianus in the context of some mortality events in Ireland; expansion of the distribution of Bonamia ostreae in Ireland; and presumed involvement in mortality events of Vibrio splendidus in Mediterranean mussel in France, a Paramarteilia in velvet crab in Ireland, and Perkinsus olseni in carpet clam in Portugal. Observation again in 2016 of a Marteilia infecting Pacific oyster in Europe warrants further investigation given potential implications for management. Observation of “wild-type” OsHV-1 in England is remarkable in revealing the persistence of non-μvar lineages of this pathogen in at least one European location.