I have researched the impacts of Hyalophysa lynni, an infectious ciliate largely responsible for shrimp Black Gill (sBG) disease in the South Atlantic Bight on the commercial shrimp fishery in Georgia (USA).
Experiments in this system revealed that transmission was highly variable across seasons, but parasite-induced host mortality and recovery rates remained stable. I used these experiments to parameterize a mechanistic model that determined H. lynni infection patterns were independent of local commercial shrimp densities. Rather, seasonal changes to environmental transmission rates, likely due to temperature-driven changes to host and parasite physiology, were responsible for intra-annual variation in disease prevalence.
This information is critical as climate change is likely to impact this system due to its reliance on environmental parameters to drive transmission, potentially increasing the duration and severity of sBG epidemics over time.
This research was recently published in a special issue of Philosophical Transactions B. https://royalsocietypublishing.org/rstb/article/381/1945/20240327/480665/Changes-in-transmission-rates-drive-seasonal?searchresult=1
Supporting work developing a methodology to remove sBG from infected hosts is available at: https://bioone.org/journals/journal-of-shellfish-research/volume-42/issue-1/035.042.0114/A-Methodology-to-Produce-Specific-Pathogen-Free-Penaeid-Shrimp-for/10.2983/035.042.0114.short
