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Shellfish fisheries and aquaculture within the Chesapeake Bay (hereafter 'the Bay') and its tributaries have been historically impacted by disease and climate events. Climate-driven shifts in temperature and salinity can alter host-parasite dynamics, influencing outbreaks. Here, we explore the relationship between temperature, salinity and parasite distribution and abundance in the eastern oysterCrassostrea virginica-Perkinsus marinussystem. We use long-term (30 yr) environmental data andP. marinussurveys in the Bay to identify (1) how climate affectsP. marinusprevalence and intensity, (2) seasonal and climate-driven infection patterns, and (3) regional environmental influences on disease. We found significant relationships betweenP. marinusinfection intensity, prevalence, increasing temperature and decreasing salinity. Our results indicated that there is an overall decreased abundance ofP. marinusprevalence and intensity throughout the Bay driven by decreases in salinity over time, most prominently from 2003-2020. However, these temporal trends in prevalence and intensity vary largely by region, with some regions still experiencing high disease burden. Examining monthly environmental parameters reinforced the dominant role of salinity in driving disease patterns. Salinity had significant relationships with prevalence and intensity year-round, with the largest effects in late spring/early summer. Monthly temperatures had fewer significant relationships to prevalence and intensity, but the largest significant effects were seen in late winter/early spring. Notably, this study is the first to document that winter salinity influences fall parasite prevalence, sometimes exerting a greater effect than temperature. Continued and expanded monitoring of marine disease is crucial to understand how the changing climate is impacting disease.
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This content will become publicly available on March 5, 2027
Salt in the wound: consequences of changing salinities on marine disease
Abstract Salinity plays an important role in the physiology of marine organisms and their pathogens. As the climate continues to change, marine and estuarine salinities may become more extreme and irregular, potentially altering host–pathogen interactions. In this review, we explore and highlight the role of salinity on a range of pathosystems, outlining impacts to the host, pathogen and their interactions. We present fisheries and aquaculture-focused case studies, including behavioural preferences for freshwater in sea louse-infested trout and the use of freshwater as a delouser in salmon aquaculture, the effects of rainfall and drought on prevalence of a lethal parasitic infection of crustaceans, as well as low saline environments as refugia from oyster disease. We also present a case study of human health risks examining how changing coastal salinities can affect seafood-associated illnesses, and a conservation-directed case study examining the role of salinity and disease in defining the distribution of a habitat-forming species. Changing climatic conditions drive diverse salinity-altered epidemiological outcomes in these pathosystems. As salinities become more variable and less predictable, and fisheries management and marine conservation require increasing priority, future studies investigating multiple stressors, salinity included, on pathosystems will provide insights into organism and ecosystem resilience under future climate scenarios. This article is part of the theme issue ‘Managing infectious marine diseases in wild populations’.
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- Award ID(s):
- 2109607
- PAR ID:
- 10688106
- Publisher / Repository:
- Philosophical Transactions B
- Date Published:
- Journal Name:
- Philosophical Transactions B
- Volume:
- 381
- Issue:
- 1945
- ISSN:
- 0962-8436
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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