scholarly journals Host plasticity supports spread of an aquaculture introduced virus to an ecosystem engineer

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Babette Bookelaar ◽  
Sharon A. Lynch ◽  
Sarah C. Culloty

Abstract Background The common cockle Cerastoderma edule plays an important ecological role in the marine ecosystem both as an infaunal engineer (reef forming and bioturbation) and a food source for protected bird species in its European range. Cockle beds are found in close proximity to aquaculture and fisheries operations, which can be “hot spots” for infectious agents including viruses and bacteria. Ostreid herpesvirus-1 microVar (OsHV-1 μVar) has spread to many Pacific oyster Crassostrea gigas culture sites globally, where it has been associated with significant mortalities in this cultured bivalve. Knowledge on the impact of the virus on the wider ecosystem, is limited. As the likelihood of released virus dispersing into the wider aquatic ecosystem is high, the plasticity of the virus and the susceptibility of C. edule to act as hosts or carriers is unknown. Methods In this study, wild C. edule were sampled biweekly at two C. gigas culture sites over a four-month period during the summer when OsHV-1 μVar prevalence is at its highest in oysters. C. edule were screened for the virus molecularly (PCR, qPCR and Sanger sequencing) and visually (in situ hybridisation (ISH)). The cockle’s ability to act as a carrier and transmit OsHV-1 μVar to the oyster host at a temperature of 14 ℃, when the virus is considered to be dormant until water temperatures exceed 16 ℃, was also assessed in laboratory transmission trials. Results The results demonstrated that OsHV-1 μVar was detected in all C. edule size/age cohorts, at both culture sites. In the laboratory, viral transmission was effected from cockles to naïve oysters for the first time, five days post-exposure. The laboratory study also demonstrated that OsHV-1 μVar was active and was successfully transmitted from the C. edule at lower temperatures. Conclusions This study demonstrates that OsHV-1 μVar has the plasticity to infect the keystone species C. edule and highlights the possible trophic transmission of the virus from cockles to their mobile top predators. This scenario would have important implications, as a greater geographical range expansion of this significant pathogen via migratory bird species may have an impact on other species that reside in bird habitats most of which are special areas of conservation.

2018 ◽  
Vol 10 (2) ◽  
pp. 11290 ◽  
Author(s):  
M. N. Harisha ◽  
B. B. Hosetti

This study was carried out to assess the status and conservation issues of migratory water birds in Komaranahalli Kere, a lake in Malebennur, Harihar Taluk, Davanagere District from November 2012 to October 2013. The dominant family was Ardeidae represented by 10 species, followed by the Scolopacidae with seven species.  The families with lowest representations of one species were Podicipididae, Anhingidae, Rostratulidae and Recurvirostridae. The study revealed that the lake harbors many resident and a few migratory bird species. Among the species recorded five species namely the Black-headed Ibis Threskiornis melanocephalus, Oriental Darter Anhinga melanogaster, Black-tailed Godwit Limosa limosa, Painted Stork Mycteria leucocephala and River Tern Sterna aurantia are Near Threatened. The present study location is also facing tremendous conservation challenges by the impact of anthropogenic alteration of the habitats in and around the lake. Though the lake is highly disturbed, it still provides some potential habitats for a few migratory and several resident water bird species. 


2018 ◽  
Vol 10 (2) ◽  
pp. 11295
Author(s):  
M. N. Harisha ◽  
B. B. Hosetti

This study was carried out to assess the status and conservation issues of migratory water birds in Komaranahalli Kere, a lake in Malebennur, Harihar Taluk, Davanagere District from November 2012 to October 2013. The dominant family was Ardeidae represented by 10 species, followed by the Scolopacidae with seven species.  The families with lowest representations of one species were Podicipididae, Anhingidae, Rostratulidae and Recurvirostridae. The study revealed that the lake harbors many resident and a few migratory bird species. Among the species recorded five species namely the Black-headed Ibis Threskiornis melanocephalus, Oriental Darter Anhinga melanogaster, Black-tailed Godwit Limosa limosa, Painted Stork Mycteria leucocephala and River Tern Sterna aurantia are Near Threatened. The present study location is also facing tremendous conservation challenges by the impact of anthropogenic alteration of the habitats in and around the lake. Though the lake is highly disturbed, it still provides some potential habitats for a few migratory and several resident water bird species. 


Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 94
Author(s):  
Alain Hambuckers ◽  
Simon de Harenne ◽  
Eberth Rocha Ledezma ◽  
Lilian Zúñiga Zeballos ◽  
Louis François

Species distribution models (SDMs) are commonly used with climate only to predict animal distribution changes. This approach however neglects the evolution of other components of the niche, like food resource availability. SDMs are also commonly used with plants. This also suffers limitations, notably an inability to capture the fertilizing effect of the rising CO2 concentration strengthening resilience to water stress. Alternatively, process-based dynamic vegetation models (DVMs) respond to CO2 concentration. To test the impact of the plant modelling method to model plant resources of animals, we studied the distribution of a Bolivian macaw, assuming that, under future climate, DVMs produce more conservative results than SDMs. We modelled the bird with an SDM driven by climate. For the plant, we used SDMs or a DVM. Under future climates, the macaw SDM showed increased probabilities of presence over the area of distribution and connected range extensions. For plants, SDMs did not forecast overall response. By contrast, the DVM produced increases of productivity, occupancy and diversity, also towards higher altitudes. The results offered positive perspectives for the macaw, more optimistic with the DVM than with the SDMs, than initially assumed. Nevertheless, major common threats remain, challenging the short-term survival of the macaw.


2012 ◽  
Vol 279 (1742) ◽  
pp. 3520-3526 ◽  
Author(s):  
Brian Tilston Smith ◽  
Amei Amei ◽  
John Klicka

Climatic and geological changes across time are presumed to have shaped the rich biodiversity of tropical regions. However, the impact climatic drying and subsequent tropical rainforest contraction had on speciation has been controversial because of inconsistent palaeoecological and genetic data. Despite the strong interest in examining the role of climatic change on speciation in the Neotropics there has been few comparative studies, particularly, those that include non-rainforest taxa. We used bird species that inhabit humid or dry habitats that dispersed across the Panamanian Isthmus to characterize temporal and spatial patterns of speciation across this barrier. Here, we show that these two assemblages of birds exhibit temporally different speciation time patterns that supports multiple cycles of speciation. Evidence for these cycles is further corroborated by the finding that both assemblages consist of ‘young’ and ‘old’ species, despite dry habitat species pairs being geographically more distant than pairs of humid habitat species. The matrix of humid and dry habitats in the tropics not only allows for the maintenance of high species richness, but additionally this study suggests that these environments may have promoted speciation. We conclude that differentially expanding and contracting distributions of dry and humid habitats was probably an important contributor to speciation in the tropics.


2014 ◽  
Vol 1010-1012 ◽  
pp. 121-125
Author(s):  
Wen Bin Li ◽  
Zhi Ming Mo ◽  
Xing Ting Chen ◽  
Chun Huang ◽  
Ming Feng Xu

To examine the impact of habitat heterogeneity on the bird communities, we investigated the structural differences of various bird communities occurring in heterogeneous habitats in the subtropical hilly areas of southern China. We used indicator Species Analysis (ISA) to test the association of specific bird species to particular habitats. We performed Two-way Cluster Analysis to find species patterning in response to habitat fragmentation. Our results demonstrated that heterogeneous habitats promoted bird diversity and human activities affected bird behavior. Indicator Species Analysis demonstrated that similar habitats had similar bird communities, while different habitats supported various bird indicator species. Although habitat diversity increased bird diversity of a region, it was unfavorable for the maintenance of specialized birds in the forests of the subtropical hilly area.


2007 ◽  
Vol 53 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Jennifer R Huddleston ◽  
John C Zak ◽  
Randall M Jeter

Members of the bacterial genus Aeromonas are widely isolated from aquatic environments and studied in part for their ability to act as opportunistic pathogens in a variety of animals. All aeromonads, with the exception of Aeromonas trota, are generally thought to be resistant to ampicillin, so the antibiotic is frequently added to isolation medium as a selective agent. In this study, 282 aeromonads from environmental sources were isolated on a medium without ampicillin and their resistance to ampicillin determined. Of the 104 of these isolates that were judged to be independent (nonredundant), 18 (17.3%) were susceptible to ampicillin. A chi-square analysis was performed to determine the impact of ampicillin use on enumerating Aeromonas species from environmental samples. Our results indicate that, when ampicillin is used as a selective agent, a significant portion of the aeromonad population in at least some environ ments can be omitted from isolation.Key words: Aeromonas, ampicillin, selective media.


Birds ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 261-274
Author(s):  
Heather L. Bateman ◽  
Sidney B. Riddle ◽  
Erin S. Cubley

Passive acoustic recorders have been used successfully as automated survey tools to detect terrestrial wildlife. However, few studies have monitored Neotropical migratory bird use of riparian forest habitat using this technology. Within dryland ecosystems, the forests along rivers support high bird diversity. Many bird species of conservation concern require these floodplain forest habitats for foraging, migration stop-overs, and breeding. Few studies have explored the use of acoustic records in riverine systems designated for conservation for their natural resource value via the Wild and Scenic Rivers Act in the USA. Using acoustic recorders, we document vocal activity of four riparian-obligate species (Bell’s Vireo, Vireo bellii; Summer Tanager, Piranga rubra; Yellow Warbler, Setophaga petechial; and Yellow-billed Cuckoo, Coccyzus americanus) to determine species occurrence along a Wild and Scenic River. We established three study reaches along the perennial Lower Verde River, in the Sonoran Desert of central Arizona, USA. Nine acoustic recorders were used over the period of 80–120 days during the summer of 2018. We measured vegetation composition and structure in 100 m2 plots paired with acoustic recorders. Visualizing vocal activity showed that three species were calling and singing at each reach; whereas, one species, the cuckoo, had fewer recordings and occurred later in the summer. We demonstrate the utility of acoustic monitoring even when applied to rare birds in complex riparian habitats. This information is important for land management and conservation efforts concerning these species of interest and identifying important habitat features in Southwestern US riparian woodlands.


2021 ◽  
Author(s):  
Stephanie Jones ◽  
Mohit Singh ◽  
Denis Duft ◽  
Alexei Kiselev ◽  
Thomas Leisner

<p>The impact of atmospheric aerosol on the climate remains poorly understood. Organic aerosol makes up a significant fraction of total aerosol and is prevalent throughout the atmosphere. It can exist as a liquid, semi-solid or amorphous solid. The viscosity of organic aerosol will have an impact on transformations that organic aerosol will undergo during its lifetime such as evaporation and growth, heterogeneous and photochemical reactions as well as the ability to act as an ice nucleating particle.  Therefore, it is of key importance to be able to determine aerosol viscosity over a range of atmospherically relevant conditions in order to better understand the impact of organic aerosol on the climate.</p> <p>Here we report proof of concept viscosity measurements of water droplets levitated in an electrodynamic balance over a range of temperatures. Charged droplets are levitated in a temperature and relative humidity-controlled environment allowing properties over a temperature range of 300 to 220 K to be studied. As the droplets evaporate they reach a point where Coulomb instabilities are induced resulting in droplet oscillations. The relaxation of these oscillations can then be probed to determine the droplet viscosity. Future work will involve determination of the viscosity of different types of organic aerosol over a broad temperature range.</p>


Sign in / Sign up

Export Citation Format

Share Document