Long Island is at the southern extreme of the Atlantic cod distribution. Therefore, the possibility of infectious diseases causing problems for this species is heightened at suboptimal temperature ranges. A recent paper on gadid infections found over 100 parasitic species on Atlantic cod, 80% of which were generalists. This work further showed that wild-captured cod had higher incidences of parasitism than cultured cod. Of these diseases, the most prevalent were Nodavirus, Trichodinids, Loma spp., Aeromonas typical and atypical, V. anguillarum serotype 2b and Lerneaocerids (branchialis), which has flounder as an intermediate host.

Picture provided by Ronald Melanson and Brian Blanchard
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Atlantic cod is a possible species for offshore aquaculture, and any culture of cod in the waters of eastern Long Island could act as a source or even sink for parasites on wild juveniles naturally occurring in these waters. Most importantly, nodavirus is a common pathogen found throughout northern Europe and Canada to infect Atlantic cod and that causes large-scale mortality events under stressful conditions. We are currently in a unique position to determine baseline prevalences of these pathogens in wild cod populations in local waters. Lack of such baseline prevalence information has been a particular problem for salmonid culture throughout the world, making the impacts of culture operations on parasite levels in local populations difficult to determine.