scholarly journals Nutritional input from dinoflagellate symbionts in reef-building corals is minimal during planula larval life stage

2016 ◽  
Vol 2 (3) ◽  
pp. e1500681 ◽  
Author(s):  
Christophe Kopp ◽  
Isabelle Domart-Coulon ◽  
Dominique Barthelemy ◽  
Anders Meibom

Dispersion of larval offspring is of fundamental ecological importance to sessile marine organisms. Photosymbiotic planulae emitted by many reef-forming corals may travel over large distances before settling to form a new colony. It is not clear whether the metabolic requirements of these planula larvae are met exclusively with lipid and protein reservoirs inherited from the mother colony or when metabolic inputs from their endosymbiotic dinoflagellates become important. Pulse-chase experiments using [13C]bicarbonate and [15N]nitrate, combined with subcellular structural and isotopic imaging of freshly emitted symbiotic larvae from the coralPocillopora damicornis, show that metabolic input from the dinoflagellates is minimal in the planulae compared with adult colonies. The larvae are essentially lecithotrophic upon emission, indicating that a marked shift in metabolic interaction between the symbiotic partners takes place later during ontogeny. Understanding the cellular processes that trigger and control this metabolic shift, and how climate change might influence it, is a key challenge in coral biology.

Hydrobiologia ◽  
2020 ◽  
Author(s):  
Alexandra Loveridge ◽  
Cathy H. Lucas ◽  
Kylie A. Pitt

AbstractScyphozoan jellyfish blooms display high interannual variability in terms of timing of appearance and size of the bloom. To understand the causes of this variability, the conditions experienced by the polyps prior to the production of ephyrae in the spring were examined. Polyps reared from planula larvae of Aurelia aurita medusae collected from southern England (50°49′58.8; − 1°05′36.9) were incubated under orthogonal combinations of temperature (4, 7, 10 °C) and duration (2, 4, 6, 8 weeks), representing the range of winter conditions in that region, before experiencing an increase to 13 °C. Timing and success of strobilation were recorded. No significant production of ephyrae was observed in any of the 2- and 4-week incubations, or in any 10 °C incubation. Time to first ephyra release decreased with longer winter incubations, and more ephyrae were produced following longer and colder winter simulations. This experiment indicates that A. aurita requires a minimum period of cooler temperatures to strobilate, and contradicts claims that jellyfish populations will be more prevalent in warming oceans, specifically in the context of warmer winter conditions. Such investigations on population-specific ontogeny highlights the need to examine each life stage separately as well as in the context of its environment.


Author(s):  
Samweli Faraja Miyayo ◽  
Patrick Opiyo Owili ◽  
Miriam Adoyo Muga ◽  
Tang-Huang Lin

In 2018, 70% of global fatalities due to pneumonia occurred in about fifteen countries, with Tanzania being among the top eight countries contributing to these deaths. Environmental and individual factors contributing to these deaths may be multifaceted, but they have not yet been explored in Tanzania. Therefore, in this study, we explore the association between climate change and the occurrence of pneumonia in the Tanga Region, Tanzania. A time series study design was employed using meteorological and health data of the Tanga Region collected from January 2016 to December 2018 from the Tanzania Meteorological Authority and Health Management Information System, respectively. The generalized negative binomial regression technique was used to explore the associations between climate indicators (i.e., precipitation, humidity, and temperature) and the occurrence of pneumonia. There were trend differences in climate indicators and the occurrence of pneumonia between the Tanga and Handeni districts. We found a positive association between humidity and increased rates of non-severe pneumonia (incidence rate ratio (IRR) = 1.01; 95% CI: 1.01–1.02; p ≤ 0.05) and severe pneumonia (IRR = 1.02; 95% CI: 1.01–1.03; p ≤ 0.05). There was also a significant association between cold temperatures and the rate of severe pneumonia in Tanga (IRR = 1.21; 95% CI: 1.11–1.33; p ≤ 0.001). Other factors that were associated with pneumonia included age and district of residence. We found a positive relationship between humidity, temperature, and incidence of pneumonia in the Tanga Region. Policies focusing on prevention and control, as well as promotion strategies relating to climate change-related health effects should be developed and implemented.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 119
Author(s):  
Antonio Fidel Santos-Hernández ◽  
Alejandro Ismael Monterroso-Rivas ◽  
Diódoro Granados-Sánchez ◽  
Antonio Villanueva-Morales ◽  
Malinali Santacruz-Carrillo

The tropical rainforest is one of the lushest and most important plant communities in Mexico’s tropical regions, yet its potential distribution has not been studied in current and future climate conditions. The aim of this paper was to propose priority areas for conservation based on ecological niche and species distribution modeling of 22 species with the greatest ecological importance at the climax stage. Geographic records were correlated with bioclimatic temperature and precipitation variables using Maxent and Kuenm software for each species. The best Maxent models were chosen based on statistical significance, complexity and predictive power, and current potential distributions were obtained from these models. Future potential distributions were projected with two climate change scenarios: HADGEM2_ES and GFDL_CM3 models and RCP 8.5 W/m2 by 2075–2099. All potential distributions for each scenario were then assembled for further analysis. We found that 14 tropical rainforest species have the potential for distribution in 97.4% of the landscape currently occupied by climax vegetation (0.6% of the country). Both climate change scenarios showed a 3.5% reduction in their potential distribution and possible displacement to higher elevation regions. Areas are proposed for tropical rainforest conservation where suitable bioclimatic conditions are expected to prevail.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Candauda Arachchige Saliya ◽  
Suesh Kumar Pandey

Purpose This paper aims to investigate how and to what extent the Fijian sustainable banking regulations or guidelines are designed, communicated, implemented and monitored within the financial system in Fiji. A scorecard is introduced for this purpose to assess the effectiveness of Fiji’s financial battle against climate change (FBACC). Design/methodology/approach This study uses a mixed-method methodology. Data were collected mainly from a survey and supplemented by interviews, observations and documents. The scorecard was developed by building on existing two theoretical frameworks, namely, the Sustainable Banking Assessment and Climate Change Governance Index, to make them more appropriate and practically applicable to less developed financial systems in emerging economies such as Fiji. This FBACC scorecard consists of four perspectives, eight critical factors and 24 criteria. Findings The results show that the overall FBACC score averages 40.75%, and all the perspectives scored below 50%, the benchmark. Only the CF “policy” scored 54.25% because of a high positive response of 82.3% for the “political leadership” criterion. The relative contributions of each perspective in constructing the overall score are distributed as 28%, 25%, 24% and 23% among planning, action, accountability and control, respectively. Research limitations/implications These results were complemented by the information shared during the interviews and confirmed that the existing political initiatives need to be effectively communicated and/or implemented in the financial system by the regulatory agencies. Practical implications This FBACC scorecard can be applied to other underdeveloped systems in emerging countries to assess the effectiveness of the sustainable banking regulations and/or guidelines in those countries in relation to the FBACC. It can also be applied to individual firms to assess their contribution to the FBACC. Originality/value To the authors’ best knowledge, this might be the first study in Fiji that considers the impact of climate-related financial risk on the Fijian financial system.


FACETS ◽  
2017 ◽  
Vol 2 (2) ◽  
pp. 610-641 ◽  
Author(s):  
Rebekah A. Oomen ◽  
Jeffrey A. Hutchings

The need to better understand how plasticity and evolution affect organismal responses to environmental variability is paramount in the face of global climate change. The potential for using RNA sequencing (RNA-seq) to study complex responses by non-model organisms to the environment is evident in a rapidly growing body of literature. This is particularly true of fishes for which research has been motivated by their ecological importance, socioeconomic value, and increased use as model species for medical and genetic research. Here, we review studies that have used RNA-seq to study transcriptomic responses to continuous abiotic variables to which fishes have likely evolved a response and that are predicted to be affected by climate change (e.g., salinity, temperature, dissolved oxygen concentration, and pH). Field and laboratory experiments demonstrate the potential for individuals to respond plastically to short- and long-term environmental stress and reveal molecular mechanisms underlying developmental and transgenerational plasticity, as well as adaptation to different environmental regimes. We discuss experimental, analytical, and conceptual issues that have arisen from this work and suggest avenues for future study.


2015 ◽  
Vol 61 (4) ◽  
pp. 641-652 ◽  
Author(s):  
Marie E. Delorenzo

Abstract Global climate change effects will vary geographically, and effects on estuaries should be independently considered. This review of the impacts of climate change on the ecotoxicology of chemical contaminants aims to summarize responses that are specific to estuarine species. Estuarine organisms are uniquely adapted to large fluctuations in temperature, salinity, oxygen, and pH, and yet future changes in climate may make them more susceptible to chemical contaminants. Recent research has highlighted the interactive effects of chemical and nonchemical stressors on chemical uptake, metabolism, and organism survival. Assessments have revealed that the nature of the interaction between climate variables and chemical pollution will depend on estuarine species and life stage, duration and timing of exposure, prior stressor exposure, and contaminant class. A need for further research to elucidate mechanisms of toxicity under different abiotic conditions and to incorporate climate change factors into toxicity testing was identified. These efforts will improve environmental risk assessment of chemical contaminants and management capabilities under changing climate conditions.


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