scholarly journals Climate change and pollution speed declines in zebrafish populations

2015 ◽  
Vol 112 (11) ◽  
pp. E1237-E1246 ◽  
Author(s):  
A. Ross Brown ◽  
Stewart F. Owen ◽  
James Peters ◽  
Yong Zhang ◽  
Marta Soffker ◽  
...  
Keyword(s):  
Climate Change ◽  
Sex Determination ◽  
Water Temperature ◽  
Endocrine Disrupting Chemicals ◽  
Population Viability Analysis ◽  
Population Viability ◽  
Interactive Effects ◽  
Environmental Sex Determination ◽  
Estrogen Synthesis ◽  
Inbred Populations

Endocrine disrupting chemicals (EDCs) are potent environmental contaminants, and their effects on wildlife populations could be exacerbated by climate change, especially in species with environmental sex determination. Endangered species may be particularly at risk because inbreeding depression and stochastic fluctuations in male and female numbers are often observed in the small populations that typify these taxa. Here, we assessed the interactive effects of water temperature and EDC exposure on sexual development and population viability of inbred and outbred zebrafish (Danio rerio). Water temperatures adopted were 28 °C (current ambient mean spawning temperature) and 33 °C (projected for the year 2100). The EDC selected was clotrimazole (at 2 μg/L and 10 μg/L), a widely used antifungal chemical that inhibits a key steroidogenic enzyme [cytochrome P450(CYP19) aromatase] required for estrogen synthesis in vertebrates. Elevated water temperature and clotrimazole exposure independently induced male-skewed sex ratios, and the effects of clotrimazole were greater at the higher temperature. Male sex ratio skews also occurred for the lower clotrimazole exposure concentration at the higher water temperature in inbred fish but not in outbred fish. Population viability analysis showed that population growth rates declined sharply in response to male skews and declines for inbred populations occurred at lower male skews than for outbred populations. These results indicate that elevated temperature associated with climate change can amplify the effects of EDCs and these effects are likely to be most acute in small, inbred populations exhibiting environmental sex determination and/or differentiation.

Invasive predators represent the greatest extinction threat to the endangered northern bettong (Bettongia tropica)

2018 ◽  
Vol 45 (3) ◽  
pp. 208 ◽  
Author(s):  
Tegan Whitehead ◽  
Karl Vernes ◽  
Miriam Goosem ◽  
Sandra E. Abell
Keyword(s):  
Climate Change ◽  
Synergistic Effects ◽  
Management Strategies ◽  
Population Viability Analysis ◽  
Population Viability ◽  
Active Management ◽  
Feral Cats ◽  
Juvenile Mortality ◽  
Management Actions ◽  
Eastern Australia

Context Identification of key threats to endangered species is vital for devising effective management strategies, but may be hindered when relevant data is limited. A population viability approach may overcome this problem. Aims We aimed to determine the population viability of endangered northern bettongs (Bettongia tropica) in north-eastern Australia. We also assessed the key threats to the population resilience and how the population viability responds to increases in mortality rates and changes in fire and drought frequency. Methods Using population viability analysis (PVA) we modelled survival probability of B. tropica populations under likely scenarios, including: (1) increased predation; (2) changes in drought and fire frequency predicted with anthropogenic climate change; and (3) synergistic effects of predation, fire and drought. Key results Population viability models suggest that populations are highly vulnerable to increases in predation by feral cats (Felis catus), and potentially red fox (Vulpes vulpes) should they colonise the area, as juvenile mortality is the main age class driving population viability. If B. tropica become more vulnerable to predators during post-fire vegetation recovery, more frequent fires could exacerbate effects of low-level cat predation. In contrast, it was predicted that populations would be resilient to the greater frequency of droughts expected as a result of climate change, with high probabilities of extinctions only predicted under the unprecedented and unlikely scenario of four drought years in 10. However, since drought and fire are interlinked, the impacts of predation could be more severe with climate change should predation and fire interact to increase B. tropica mortality risk. Conclusion Like other Potoroids, B. tropica appear highly vulnerable to predation by introduced mammalian predators such as feral cats. Implications Managers need information allowing them to recognise scenarios when populations are most vulnerable to potential threats, such as drought, fire and predation. PVA modelling can assess scenarios and allow pro-active management based on predicted responses rather than requiring collection of extensive field data before management actions. Our analysis suggests that assessing and controlling predator populations and thereby minimising predation, particularly of juveniles, should assist in maintaining stability of populations of the northern bettong.

scholarly journals The role of land use and land cover change in climate change vulnerability assessments of biodiversity: a systematic review

2021 ◽  
Author(s):  
Maria J. Santos ◽  
Adam B. Smith ◽  
Stefan C. Dekker ◽  
Maarten B. Eppinga ◽  
Pedro J. Leitão ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Cover ◽  
Population Viability ◽  
Interactive Effects ◽  
Negative Effects ◽  
Climate Change Vulnerability ◽  
Management Intervention ◽  
Vulnerability Assessments

Abstract Context For many organisms, responses to climate change (CC) will be affected by land-use and land-cover changes (LULCC). However, the extent to which LULCC is concurrently considered in climate change vulnerability assessments (CCVAs) is unclear. Objectives We identify trends in inclusion of LULCC and CC in vulnerability assessments of species and the direction and magnitude of their combined effect on biodiversity. Further, we examine the effect size of LULCC and CC in driving changes in “currencies” of response to CC, such as distribution, abundance and survival. Methods We conducted a systematic literature review of articles published in the last 30 years that focused on CCVA and accounted for impacts of both CC and LULCC. Results Across 116 studies, 34% assumed CC and LULCC would act additively, while 66% allowed for interactive effects. The majority of CCVAs reported similar effect sizes for CC and LULCC, although they affected different CCVA currencies. Only 14% of the studies showed larger effects of CC than of LULCC. Another 14% showed larger effects of LULCC than CC, specifically for dispersal, population viability, and reproduction, which tend to be strongly affected by fragmentation and disturbance. Although most studies found that LULCC and CC had negative effects on species currencies, in some cases effects were neutral or even positive. Conclusions CCVAs that incorporate LULCC provided a better account of drivers of vulnerability, and highlight aspects of drivers that are generally more amenable to on-the-ground management intervention than CCVAs that focus on CC alone.

scholarly journals Climate and land-use changes interact to drive long-term reorganization of riverine fish communities globally

2021 ◽  
Vol 118 (27) ◽  
pp. e2011639118
Author(s):  
Lise Comte ◽  
Julian D. Olden ◽  
Pablo A. Tedesco ◽  
Albert Ruhi ◽  
Xingli Giam
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Temperature ◽  
Land Use Changes ◽  
Fish Communities ◽  
Biodiversity Loss ◽  
Interactive Effects ◽  
Distribution Ranges ◽  
Spatially Varying ◽  
Riverine Systems

As climate change unfolds, changes in population dynamics and species distribution ranges are expected to fundamentally reshuffle communities worldwide. Yet, a comprehensive understanding of the mechanisms and extent of community reorganization remains elusive. This is particularly true in riverine systems, which are simultaneously exposed to changing temperature and streamflow, and where land-use change continues to be a major driver of biodiversity loss. Here, we use the most comprehensive compilation of fish abundance time series to date to provide a global synthesis of climate- and LU-induced effects on riverine biota with respect to changes in species thermal and streamflow affinities. We demonstrate that fish communities are increasingly dominated by thermophilic (warm-water) and limnophilic (slow-water) species. Despite being consistent with trends in water temperature and streamflow observed over recent decades, these community changes appear largely decoupled from each other and show wide spatial variation. We further reveal a synergy among climate- and land use-related drivers, such that community thermophilization is heightened in more human-modified systems. Importantly, communities in which species experience thermal and flow regimes that approach or exceed their tolerance thresholds (high community sensitivity), as well as species-poor communities (low community resilience), also display faster rates of compositional change. This research illustrates that quantifying vulnerability of riverine systems to climate change requires a broadening from a narrower thermal focus to more integrative approaches that account for the spatially varying and multifaceted sensitivity of riverine organisms to the interactive effects of water temperature, hydrology, and other anthropogenic changes.

scholarly journals Sex reversal and ontogeny under climate change and chemical pollution: are there interactions between the effects of elevated temperature and a xenoestrogen on early development in agile frogs?

2020 ◽  
Author(s):  
Zsanett Mikó ◽  
Edina Nemesházi ◽  
Nikolett Ujhegyi ◽  
Viktória Verebélyi ◽  
János Ujszegi ◽  
...  
Keyword(s):  
Climate Change ◽  
High Temperature ◽  
Sex Determination ◽  
Body Mass ◽  
Endocrine Disrupting Chemicals ◽  
Sex Reversal ◽  
Chemical Pollution ◽  
Genetic Sexing ◽  
Simultaneous Exposure ◽  
Individual Fitness

Anthropogenic environmental change poses a special threat to species in which genetic sex determination can be overwritten by the thermal and chemical environment. Endocrine disrupting chemicals as well as extreme temperatures can induce sex reversal in such species, with wide-ranging consequences for fitness, demography, population viability and evolution. Despite accumulating evidence suggesting that chemical and thermal effects may interact in ecological contexts, little is known about their combined effects on sex reversal. Here we assessed the simultaneous effects of high temperature (masculinizing agent) and 17α-ethinylestradiol (EE2), a widespread xenoestrogen (feminizing agent), on sexual development and fitness-related traits in agile frogs (Rana dalmatina). We exposed tadpoles to a six-days heat wave (30°C) and/or an ecologically relevant concentration of EE2 (30 ng/L) in one of three consecutive larval periods, and diagnosed sex reversals two months after metamorphosis using species-specific markers for genetic sexing. We found that high temperature induced female-to-male sex reversal, decreased survival, delayed metamorphosis, decreased body mass at metamorphosis, and increased the proportion of animals that had no fat bodies, while EE2 had no effect on these traits. Simultaneous exposure to heat and EE2 had non-additive effects on juvenile body mass, which were dependent on treatment timing and further complicated by a negative effect of sex reversal on body mass. These results show that environmentally relevant exposure to EE2 does not diminish the masculinizing effects of high temperature. Instead, our findings on growth suggest that climate change and chemical pollution may have complex consequences for individual fitness and population persistence in species with environment-sensitive sex determination.

Sign in / Sign up

Export Citation Format

Share Document