scholarly journals Disease-driven mass mortality event leads to widespread extirpation and variable recovery potential of a marine predator across the eastern Pacific

2021 ◽  
Vol 288 (1957) ◽  
pp. 20211195
Author(s):  
S. L. Hamilton ◽  
V. R. Saccomanno ◽  
W. N. Heady ◽  
A. L. Gehman ◽  
S. I. Lonhart ◽  
...  
Keyword(s):  
Baja California ◽  
Gulf Of Alaska ◽  
Mass Mortality ◽  
Sea Star ◽  
Wasting Disease ◽  
Marine Predator ◽  
Mass Mortality Event ◽  
Recovery Potential ◽  
Southern Half

The prevalence of disease-driven mass mortality events is increasing, but our understanding of spatial variation in their magnitude, timing and triggers are often poorly resolved. Here, we use a novel range-wide dataset comprised 48 810 surveys to quantify how sea star wasting disease affected Pycnopodia helianthoides , the sunflower sea star, across its range from Baja California, Mexico to the Aleutian Islands, USA. We found that the outbreak occurred more rapidly, killed a greater percentage of the population and left fewer survivors in the southern half of the species's range. Pycnopodia now appears to be functionally extinct (greater than 99.2% declines) from Baja California, Mexico to Cape Flattery, Washington, USA and exhibited severe declines (greater than 87.8%) from the Salish Sea to the Gulf of Alaska. The importance of temperature in predicting Pycnopodia distribution rose more than fourfold after the outbreak, suggesting latitudinal variation in outbreak severity may stem from an interaction between disease severity and warmer waters. We found no evidence of population recovery in the years since the outbreak. Natural recovery in the southern half of the range is unlikely over the short term. Thus, assisted recovery will probably be required to restore the functional role of this predator on ecologically relevant time scales.

Wasting disease and static environmental variables drive sea star assemblages in the Northern Gulf of Alaska

2019 ◽  
Vol 520 ◽  
pp. 151209 ◽  
Author(s):  
Brenda Konar ◽  
Timothy James Mitchell ◽  
Katrin Iken ◽  
Heather Coletti ◽  
Thomas Dean ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Gulf Of Alaska ◽  
Sea Star ◽  
Wasting Disease

scholarly journals Tracking a mass mortality outbreak of pen shell Pinna nobilis populations: A collaborative effort of scientists and citizens

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Miguel Cabanellas-Reboredo ◽  
Maite Vázquez-Luis ◽  
Baptiste Mourre ◽  
Elvira Álvarez ◽  
Salud Deudero ◽  
...  
Keyword(s):  
Additive Model ◽  
Mass Mortality ◽  
Salinity Range ◽  
Pinna Nobilis ◽  
Mass Mortality Event ◽  
Virtual Particles ◽  
Management Measures ◽  
Pen Shell ◽  
The Mediterranean

Abstract A mass mortality event is devastating the populations of the endemic bivalve Pinna nobilis in the Mediterranean Sea from early autumn 2016. A newly described Haplosporidian endoparasite (Haplosporidium pinnae) is the most probable cause of this ecological catastrophe placing one of the largest bivalves of the world on the brink of extinction. As a pivotal step towards Pinna nobilis conservation, this contribution combines scientists and citizens’ data to address the fast- and vast-dispersion and prevalence outbreaks of the pathogen. Therefore, the potential role of currents on parasite expansion was addressed by means of drift simulations of virtual particles in a high-resolution regional currents model. A generalized additive model was implemented to test if environmental factors could modulate the infection of Pinna nobilis populations. The results strongly suggest that the parasite has probably dispersed regionally by surface currents, and that the disease expression seems to be closely related to temperatures above 13.5 °C and to a salinity range between 36.5–39.7 psu. The most likely spread of the disease along the Mediterranean basin associated with scattered survival spots and very few survivors (potentially resistant individuals), point to a challenging scenario for conservation of the emblematic Pinna nobilis, which will require fast and strategic management measures and should make use of the essential role citizen science projects can play.

scholarly journals Recruitment Disruption and the Role of Unaffected Populations for Potential Recovery After the Pinna nobilis Mass Mortality Event

2020 ◽  
Vol 7 ◽  
Author(s):  
Diego K. Kersting ◽  
Maite Vázquez-Luis ◽  
Baptiste Mourre ◽  
Fatima Z. Belkhamssa ◽  
Elvira Álvarez ◽  
...  
Keyword(s):  
Mass Mortality ◽  
Mortality Event ◽  
Pinna Nobilis ◽  
Mass Mortality Event

scholarly journals Evidence that non-pathogenic microorganisms drive sea star wasting disease through boundary layer oxygen diffusion limitation

2020 ◽  
Author(s):  
Citlalli A. Aquino ◽  
Ryan M. Besemer ◽  
Christopher M. DeRito ◽  
Jan Kocian ◽  
Ian R. Porter ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Organic Matter ◽  
Oxygen Diffusion ◽  
Marine Invertebrate ◽  
Mass Mortality ◽  
Strictly Anaerobic ◽  
Water Interface ◽  
Sea Star ◽  
Diffusion Limitation ◽  
Wasting Disease

ABSTRACTSea star wasting disease describes a condition affecting asteroids that resulted in significant Northeastern Pacific population decline following a mass mortality event in 2013. The etiology of sea star wasting is unresolved. We hypothesized that asteroid wasting is a sequela of microbial organic matter remineralization near respiratory surfaces which leads to boundary layer oxygen diffusion limitation (BLODL). Wasting lesions were induced in Pisaster ochraceus by enrichment with a variety of organic matter (OM) sources and by experimentally reduced oxygen conditions. Microbial assemblages inhabiting tissues and at the asteroid-water interface bore signatures of copiotroph proliferation before wasting onset, followed by the proliferation of putatively facultative and strictly anaerobic taxa. These results together illustrate that suboxic conditions at the animal-water interface may be established by heterotrophic bacterial activity in response to organic matter loading. Wasting susceptibility was significantly and positively correlated with rugosity, a key determinant of boundary layer thickness. At a semi-continuously monitored field site (Langley Harbor), wasting predictably occurred at annual peak or decline in phytoplankton biomass over 5 years, suggesting that primary production-derived OM may contribute to BLODL. Finally, wasting individuals from 2013 – 2014 bore stable isotopic signatures reflecting anaerobic processes which suggests that this phenomenon may have affected asteroids during mass mortality. The impacts of BLODL may be more pronounced under higher temperatures due to lower O2 solubility, in more rugose asteroid species due to restricted hydrodynamic flow, and in larger specimens due to their lower surface area to volume ratios which affects diffusive respiratory potential. Moreover, our results demonstrate that marine invertebrate disease may result from heterotrophic microbial activity that occurs adjacent to respiratory tissues, which raises important questions about the etiology of marine diseases in other benthic taxa.

scholarly journals Densovirus associated with sea-star wasting disease and mass mortality

2014 ◽  
Vol 111 (48) ◽  
pp. 17278-17283 ◽  
Author(s):  
Ian Hewson ◽  
Jason B. Button ◽  
Brent M. Gudenkauf ◽  
Benjamin Miner ◽  
Alisa L. Newton ◽  
...  
Keyword(s):  
Mass Mortality ◽  
Sea Star ◽  
Wasting Disease

scholarly journals Evidence That Microorganisms at the Animal-Water Interface Drive Sea Star Wasting Disease

2021 ◽  
Vol 11 ◽  
Author(s):  
Citlalli A. Aquino ◽  
Ryan M. Besemer ◽  
Christopher M. DeRito ◽  
Jan Kocian ◽  
Ian R. Porter ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Activity ◽  
Population Decline ◽  
Lower Surface ◽  
Mass Mortality ◽  
Strictly Anaerobic ◽  
Water Interface ◽  
Sea Star ◽  
Pacific Population ◽  
Mass Mortality Event

Sea star wasting (SSW) disease describes a condition affecting asteroids that resulted in significant Northeastern Pacific population decline following a mass mortality event in 2013. The etiology of SSW is unresolved. We hypothesized that SSW is a sequela of microbial organic matter remineralization near respiratory surfaces, one consequence of which may be limited O2 availability at the animal-water interface. Microbial assemblages inhabiting tissues and at the asteroid-water interface bore signatures of copiotroph proliferation before SSW onset, followed by the appearance of putatively facultative and strictly anaerobic taxa at the time of lesion genesis and as animals died. SSW lesions were induced in Pisaster ochraceus by enrichment with a variety of organic matter (OM) sources. These results together illustrate that depleted O2 conditions at the animal-water interface may be established by heterotrophic microbial activity in response to organic matter loading. SSW was also induced by modestly (∼39%) depleted O2 conditions in aquaria, suggesting that small perturbations in dissolved O2 may exacerbate the condition. SSW susceptibility between species was significantly and positively correlated with surface rugosity, a key determinant of diffusive boundary layer thickness. Tissues of SSW-affected individuals collected in 2013–2014 bore δ15N signatures reflecting anaerobic processes, which suggests that this phenomenon may have affected asteroids during mass mortality at the time. The impacts of enhanced microbial activity and subsequent O2 diffusion limitation may be more pronounced under higher temperatures due to lower O2 solubility, in more rugose asteroid species due to restricted hydrodynamic flow, and in larger specimens due to their lower surface area to volume ratios which affects diffusive respiratory potential.

Testing ecological release as a compensating mechanism for mass mortality in a keystone predator

2020 ◽  
Vol 637 ◽  
pp. 59-69 ◽  
Author(s):  
J Sullivan-Stack ◽  
BA Menge
Keyword(s):  
Community Dynamics ◽  
Limiting Factor ◽  
Sea Star ◽  
Top Predator ◽  
Oregon Coast ◽  
Ecological Release ◽  
Keystone Predator ◽  
Pisaster Ochraceus ◽  
Wasting Syndrome

Top predator decline has been ubiquitous across systems over the past decades and centuries, and predicting changes in resultant community dynamics is a major challenge for ecologists and managers. Ecological release predicts that loss of a limiting factor, such as a dominant competitor or predator, can release a species from control, thus allowing increases in its size, density, and/or distribution. The 2014 sea star wasting syndrome (SSWS) outbreak decimated populations of the keystone predator Pisaster ochraceus along the Oregon coast, USA. This event provided an opportunity to test the predictions of ecological release across a broad spatial scale and determine the role of competitive dynamics in top predator recovery. We hypothesized that after P. ochraceus loss, populations of the subordinate sea star Leptasterias sp. would grow larger, more abundant, and move downshore. We based these predictions on prior research in Washington State showing that Leptasterias sp. competed with P. ochraceus for food. Further, we predicted that ecological release of Leptasterias sp. could provide a bottleneck to P. ochraceus recovery. Using field surveys, we found no clear change in density or distribution in Leptasterias sp. populations post-SSWS, and decreases in body size. In a field experiment, we found no evidence of competition between similar-sized Leptasterias sp. and P. ochraceus. Thus, the mechanisms underlying our predictions were not in effect along the Oregon coast, which we attribute to differences in habitat overlap and food availability between the 2 regions. Our results suggest that response to the loss of a dominant competitor can be unpredictable even when based in theory and previous research.

scholarly journals Chimeric elk/mouse prion proteins in transgenic mice

2013 ◽  
Vol 94 (2) ◽  
pp. 443-452 ◽  
Author(s):  
Gültekin Tamgüney ◽  
Kurt Giles ◽  
Abby Oehler ◽  
Natrina L. Johnson ◽  
Stephen J. DeArmond ◽  
...  
Keyword(s):  
Neurodegenerative Disorder ◽  
Prion Proteins ◽  
Second Line ◽  
Mouse Line ◽  
Wasting Disease ◽  
C Terminus ◽  
Incubation Periods ◽  
N Terminus ◽  
Mouse Lines

Chronic wasting disease (CWD) of deer and elk is a highly communicable neurodegenerative disorder caused by prions. Investigations of CWD are hampered by slow bioassays in transgenic (Tg) mice. Towards the development of Tg mice that will be more susceptible to CWD prions, we created a series of chimeric elk/mouse transgenes that encode the N terminus of elk PrP (ElkPrP) up to residue Y168 and the C terminus of mouse PrP (MoPrP) beyond residue 169 (mouse numbering), designated Elk3M(SNIVVK). Between codons 169 and 219, six residues distinguish ElkPrP from MoPrP: N169S, T173N, V183I, I202V, I214V and R219K. Using chimeric elk/mouse PrP constructs, we generated 12 Tg mouse lines and determined incubation times after intracerebral inoculation with the mouse-passaged RML scrapie or Elk1P CWD prions. Unexpectedly, one Tg mouse line expressing Elk3M(SNIVVK) exhibited incubation times of <70 days when inoculated with RML prions; a second line had incubation times of <90 days. In contrast, mice expressing full-length ElkPrP had incubation periods of >250 days for RML prions. Tg(Elk3M,SNIVVK) mice were less susceptible to CWD prions than Tg(ElkPrP) mice. Changing three C-terminal mouse residues (202, 214 and 219) to those of elk doubled the incubation time for mouse RML prions and rendered the mice resistant to Elk1P CWD prions. Mutating an additional two residues from mouse to elk at codons 169 and 173 increased the incubation times for mouse prions to >300 days, but made the mice susceptible to CWD prions. Our findings highlight the role of C-terminal residues in PrP that control the susceptibility and replication of prions.

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