Disease epidemic and a marine heat wave are associated with the continental-scale collapse of a pivotal predator (Pycnopodia helianthoides)

Multihost infectious disease outbreaks have endangered wildlife, causing extinction of frogs and endemic birds, and widespread declines of bats, corals, and abalone. Since 2013, a sea star wasting disease has affected > 20 sea star species from Mexico to Alaska. The common, predatory sunflower star (Pycnopodia helianthoides), shown to be highly susceptible to sea star wasting disease, has been extirpated across most of its range. Diver surveys conducted in shallow nearshore waters (n = 10,956; 2006-2017) from California to Alaska and deep offshore (55 to 1280 m) trawl surveys from California to Washington (n = 8968; 2004-2016) reveal 80 to 100% declines across a similar to 3000-km range. Furthermore, timing of peak declines in nearshore waters coincided with anomalously warm sea surface temperatures. The rapid, widespread decline of this pivotal subtidal predator threatens its persistence and may have large ecosystem-level consequences

A tale of two sea stars: recovery (ochre star) or endangerment (sunflower star) following the 2014 epidemic

During the summers of 2013 and 2014, populations of sea stars along the west coast from Alaska to Mexico were decimated by the sea star wasting disease (SSWD) epizootic. Two of the most highly affected species along this range are Pisaster ochraceus (the ochre star), the most common intertidal species, and Pycnopodia helianthoides (the sunflower star), the most common subtidal species, both of which are endemic to the western coast of the U.S. For the ochre star, in the San Juan Islands of Washington State, we measured high case fatality rates associated with disease prevalence over 90% during the summer of 2014. Low levels of disease were observed in the summers of 2015, 2016, and 2017. Population levels following the epizootic remain stable but small, and shifted in size structure from larger to smaller stars. At one site, a dramatic increase in both juvenile and adult ochre stars occurred in 2017, giving hope for future recovery. In contrast, the most common subtidal species, the sunflower star, also suffered catastrophic mortality in 2014. However, in this case, Citizen Science Monitoring in all oceanographic basins of the Salish Sea through 2017 shows an extraordinary decimation of this species, with no sign of recovery three years after the SSWD epizootic. Extremely low population size of sunflower stars raises concern about the capacity of this species to recover, as well as to resist other stochastic events in the future

Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security

Devastating Transboundary Impacts of Sea Star Wasting Disease on Subtidal Asteroids.

Sea star wasting disease devastated intertidal sea star populations from Mexico to Alaska between 2013-15, but little detail is known about its impacts to subtidal species. We assessed the impacts of sea star wasting disease in the Salish Sea, a Canadian / United States transboundary marine ecosystem, and world-wide hotspot for temperate asteroid species diversity with a high degree of endemism. We analyzed roving diver survey data for the three most common subtidal sea star species collected by trained volunteer scuba divers between 2006-15 in 5 basins and on the outer coast of Washington, as well as scientific strip transect data for 11 common subtidal asteroid taxa collected by scientific divers in the San Juan Islands during the spring/summer of 2014 and 2015. Our findings highlight differential susceptibility and impact of sea star wasting disease among asteroid species populations and lack of differences between basins or on Washington's outer coast. Specifically, severe depletion of sunflower sea stars (Pycnopodia helianthoides) in the Salish Sea support reports of major declines in this species from California to Alaska, raising concern for the conservation of this ecologically important subtidal predator

Parameter estimates of the logistic regression for SSWD prevalence in 3 asteroid species during May—August 2014.

<p>Parameter estimates of the logistic regression for SSWD prevalence in 3 asteroid species during May—August 2014.</p

The 2006–15 estimated count of <i>P</i>. <i>helianthoides</i> in 5 basins of the Salish Sea and the Outer Coast.

<p>Grey line marks the epidemic onset.</p

Estimated mean log density change in 2015 (the red point) for 10 asteroids and their corresponding 95% credible intervals (blue lines).

<p>Estimated mean log density change in 2015 (the red point) for 10 asteroids and their corresponding 95% credible intervals (blue lines).</p

Number of REEF surveys conducted by year in each studied basin in the Salish Sea.

<p>Number of REEF surveys conducted by year in each studied basin in the Salish Sea.</p

Seasonal shedding of coronavirus by straw-colored fruit bats at urban roosts in Africa.

The straw-colored fruit bat (Eidolon helvum) is a pteropodid whose conservation is crucial for maintaining functional connectivity of plant populations in tropical Africa. Land conversion has pushed this species to adapt to roosting in urban centers across its range. These colonies often host millions of individuals, creating intensive human-bat contact interfaces that could facilitate the spillover of coronaviruses shed by these bats. A better understanding of coronavirus dynamics in these roosts is needed to identify peak times of exposure risk in order to propose evidence-based management that supports safe human-bat coexistence, as well as the conservation of this chiropteran. We studied the temporal patterns of coronavirus shedding in E. helvum, by testing thousands of longitudinally-collected fecal samples from two spatially distant urban roosts in Ghana and Tanzania. Shedding of coronaviruses peaked during the second part of pup weaning in both roosts. Assuming that coronavirus shedding is directly related to spillover risk, our results indicate that exposure mitigation should target reducing contact between people and E. helvum roosts during the pup "weaning" period. This recommendation can be applied across the many highly-populated urban sites occupied by E. helvum across Africa

The actual 2006–15 and projected 2014–15 abundance for <i>M</i>. <i>franciscanus</i> in 5 basins of the Salish Sea and the Outer Coast.

<p>Grey line marks the epidemic onset. Note: Abundance = Density Score x SF, where Density Score = [(nSx1)+(nFx2)+(nMx3)+(nAx4)] / (nS + nF + nM + nA). Here nS, nF, nM, and nA represent the number of times each abundance category was assigned for a given species.</p