CORVALLIS, Ore. — The best time to treat diseases in marine species is before an outbreak occurs, according to research from Oregon State University.
Researchers from OSU College of Science and Carlson College of Veterinary Medicine evaluated more than a dozen disease management strategies and found the most promising were proactive rather than reactive, such as improving the health of marine ecosystems and the creation of marine disease surveillance and response networks.
The findings, published in Ecological applicationsare important because marine diseases can disrupt ecosystems and threaten human livelihoods, and because disease outbreaks are expected to increase with climate change, said Sarah Gravem, research associate in integrative biology at Oregon State. .
“The ocean environment is fundamentally changing the way diseases are transmitted between marine species, which means we must also adapt our wildlife management strategies to successfully respond to disease outbreaks in the ocean,” he said. she stated. “The COVID outbreak has shown how devastating disease outbreaks can be in people, and disease in the marine environment is no different. But we are much less prepared to deal with emerging infectious diseases in wild animals. »
In particular, Gravem said, preventing or controlling outbreaks in marine systems is a challenge because pathogens can travel much longer distances at faster speeds in water than in air. Additionally, many marine species, including most invertebrates, do not have immune “memory” like humans, and many species produce larvae that float in currents and grow far from their birthplace.
“That means the tools we use to control outbreaks need to be adjusted to respond to those circumstances,” she said. “These challenges were highlighted by the 2013 outbreak of wasting starfish disease, which was easily transmitted in ocean currents and spread from Baja California, Mexico, to the Aleutians in Alaska. within a few years, affecting at least a dozen species and often causing severe declines.
This outbreak, Graven said, has prompted scientists to reconsider how to better prepare for and manage marine disease.
Graven and a team that included several graduate students looked at 17 disease management strategies to see how they compared in a marine system versus a land system. The analysis led them to identify the potentially most effective strategies for preventing, responding to and recovering from marine disease outbreaks.
“Strategies like isolation, antibiotics, culling and vaccines are less useful in the ocean than on land because organisms are difficult to isolate and many species lack immune memory,” the lead author said. of the study, Caroline Glidden, a former graduate student at OSU who is now a postdoctoral researcher at Stanford University. “On the other hand, many strategies used in terrestrial epidemics are readily implemented in marine systems. These include broad prevention strategies such as reducing pathogen transport via human activity and conservation of biodiversity and habitats with marine protected areas or other restrictions on human use.
Laurel Field, co-author of an OSU graduate student currently pursuing a Ph.D. at Florida State, said other useful outbreak response strategies are surveillance networks to quickly detect emerging diseases, diagnostic tools to test for pathogens in a host, and disease modeling that tracks or predicts the transmission.
Once a disease has caused a decline in a host population, she said, translocating healthy individuals from elsewhere can be effective and restoring habitat can aid recovery.
“For severe declines, captive breeding and reintroductions may be necessary,” Field said. “In all disease outbreaks, threatened species lists like the IUCN Red List of Threatened Species can help assess population risk, mitigate threats and speed recovery actions, and they can provide the added benefit of legal clout Marine disease management is challenging and many management tools require additional development or resources to be effective, but there are many strategies we can employ.
To improve the management of diseases in marine wildlife, and given that it is particularly difficult to stop epidemics at sea, scientists recommend preventively improving the health of the marine ecosystem and creating more networks disease surveillance and response such as USO. APRIL network.
They also advocate for greater capacity for basic research into marine disease systems and support for facilities where research can be undertaken, especially those with infrastructure to house or farm marine species.
All of the researchers’ recommendations can be backed by legislation and policy to explicitly support wildlife health, she added, noting that despite several recent efforts, there is no enacted legislation in the United States. or in the world that deals with wildlife disease emergencies.
Silke Bachhuber, Shannon Hennessey, Brittany Poirson, Zachary Randell, Erick White, Maya Feezell and Heather Fulton-Bennett from the College of Science and Robyn Cates, Lesley Cohen, Elin Crockett, Michelle Degnin-Warner and Devyn Pires also participated in the study . from the Carlson College of Veterinary Medicine.