scholarly journals Broad-scale sampling of primary freshwater fish populations reveals the role of intrinsic traits, inter-basin connectivity, drainage area and latitude on shaping contemporary patterns of genetic diversity

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1694 ◽  
Author(s):  
Carla Sousa-Santos ◽  
Joana I. Robalo ◽  
Ana M. Pereira ◽  
Paulo Branco ◽  
José Maria Santos ◽  
...  

Background.Worldwide predictions suggest that up to 75% of the freshwater fish species occurring in rivers with reduced discharge could be extinct by 2070 due to the combined effect of climate change and water abstraction. The Mediterranean region is considered to be a hotspot of freshwater fish diversity but also one of the regions where the effects of climate change will be more severe. Iberian cyprinids are currently highly endangered, with over 68% of the species raising some level of conservation concern.Methods.During the FISHATLAS project, the Portuguese hydrographical network was extensively covered (all the 34 river basins and 47 sub-basins) in order to contribute with valuable data on the genetic diversity distribution patterns of native cyprinid species. A total of 188 populations belonging to 16 cyprinid species ofSqualius, Luciobarbus, Achondrostoma, Iberochondrostoma, AnaecyprisandPseudochondrostomawere characterized, for a total of 3,678 cytochromebgene sequences.Results.When the genetic diversity of these populations was mapped, it highlighted differences among populations from the same species and between species with identical distribution areas. Factors shaping the contemporary patterns of genetic diversity were explored and the results revealed the role of latitude, inter-basin connectivity, migratory behaviour, species maximum size, species range and other species intrinsic traits in determining the genetic diversity of sampled populations. Contrastingly, drainage area and hydrological regime (permanent vs. temporary) seem to have no significant effect on genetic diversity. Species intrinsic traits, maximum size attained, inter-basin connectivity and latitude explained over 30% of the haplotype diversity variance and, generally, the levels of diversity were significantly higher for smaller sized species, from connected and southerly river basins.Discussion.Targeting multiple co-distributed species of primary freshwater fish allowed us to assess the relative role of historicalversuscontemporary factors affecting genetic diversity. Since different patterns were detected for species with identical distribution areas we postulate that contemporary determinants of genetic diversity (species’ intrinsic traits and landscape features) must have played a more significant role than historical factors. Implications for conservation in a context of climate change and highly disturbed habitats are detailed, namely the need to focus management and conservation actions on intraspecific genetic data and to frequently conduct combined genetic and demographic surveys.

2018 ◽  
Author(s):  
Hollie M. Putnam ◽  
Raphael Ritson-Williams ◽  
Jolly Ann Cruz ◽  
Jennifer M. Davidson ◽  
Ruth D. Gates

AbstractThe persistence of reef building corals is threatened by human-induced environmental change. Maintaining coral reefs into the future requires not only the survival of adults, but also the influx of recruits to promote genetic diversity and retain cover following adult mortality. Few studies examine the linkages among multiple life stages of corals, despite a growing knowledge of carryover effects in other systems. We provide a novel test of coral parental preconditioning to ocean acidification (OA) to better understand impacts on the processes of offspring recruitment and growth. Coral planulation was tracked for three months following adult exposure to high pCO2 and offspring from the second month were reciprocally exposed to ambient and high pCO2. Offspring of parents exposed to high pCO2 had greater settlement and survivorship immediately following release, retained survivorship benefits during one and six months of continued exposure, and further displayed growth benefits to at least one month post release. Enhanced performance of offspring from parents exposed to high conditions was maintained despite the survivorship in both treatments declining in continued exposure to OA. Preconditioning of the adults while they brood their larvae may provide a form of hormetic conditioning, or environmental priming that elicits stimulatory effects. Defining mechanisms of positive carryover effects, or positive trans-generational plasticity, is critical to better understanding ecological and evolutionary dynamics of corals under regimes of increasing environmental disturbance. Considering parental and environmental legacies in ecological and evolutionary projections may better account for coral reef response to the chronic stress regimes characteristic of climate change.


2012 ◽  
Vol 74 (4) ◽  
pp. 637-657 ◽  
Author(s):  
B. J. Shuter ◽  
A. G. Finstad ◽  
I. P. Helland ◽  
I. Zweimüller ◽  
F. Hölker

2019 ◽  
Author(s):  
Edward John Roy Clarke ◽  
Anna Klas ◽  
Joshua Stevenson ◽  
Emily Jane Kothe

Climate change is a politically-polarised issue, with conservatives less likely than liberals to perceive it as human-caused and consequential. Furthermore, they are less likely to support mitigation and adaptation policies needed to reduce its impacts. This study aimed to examine whether John Oliver’s “A Mathematically Representative Climate Change Debate” clip on his program Last Week Tonight polarised or depolarised a politically-diverse audience on climate policy support and behavioural intentions. One hundred and fifty-nine participants, recruited via Amazon MTurk (94 female, 64 male, one gender unspecified, Mage = 51.07, SDage = 16.35), were presented with either John Oliver’s climate change consensus clip, or a humorous video unrelated to climate change. Although the climate change consensus clip did not reduce polarisation (or increase it) relative to a control on mitigation policy support, it resulted in hyperpolarisation on support for adaptation policies and increased climate action intentions among liberals but not conservatives.


2014 ◽  
Vol 9 (4) ◽  
pp. 441-444
Author(s):  
Y. A. Dzhenis ◽  
I. I. Tuber

Soil is a powerful and active absorber of many substances, assumes the pressure of industrial and municipal emissions and waste, and performs the important role of a buffer and a detoxicant. It accumulates heavy metals, pesticides, hydrocarbons and other chemical polluting substances and due to the soil absorbing complex (SAC) strongly captures and protects natural waters and the atmosphere from harm. Applying sewage sludges in our research will enable us to strengthen the capacity of SAC and to reduce the toxicity of heavy metals when they enter a reservoir via a drain from anthropogenically polluted territory.


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