scholarly journals Cumulative impacts of anthropogenic stressors on macrobenthic communities at a bay-scale: an experimental approach

2018 ◽  
Author(s):  
Charlotte Carrier-Belleau ◽  
Philippe Archambault ◽  
Christopher W. McKindsey
Keyword(s):  
Experimental Approach ◽  
Multiple Stressors ◽  
Benthic Communities ◽  
Species Conservation ◽  
Environmental Stressors ◽  
Cumulative Impacts ◽  
Anthropogenic Stressors ◽  
Biological Responses ◽  
Manipulative Experiments

Human activities such as maritime transport, fishing and aquaculture create environmental stressors affecting the structure and the functioning of benthic communities. While these disturbances can act individually, they can also act synergistically and lead to changes more difficult to predict. The bay of Sept-Îles hosts a harbour receiving the most important ballast volume in North America and represents one of the most eutrophic bays in the Gulf of St. Lawrence. This project is part of the Canadian healthy oceans network (CHONe II) and attempts to identify the effect of the interaction of anthropogenic stressors on the macrobenthic invertebrate communities in the bay of Sept-Îles. In situ and laboratory manipulative experiments will be conducted to determine the influence of stressors on biological responses when taken individually, and when these stressors interact through time at different intensities. In that way, these experiments will improve our knowledge of cumulated impacts of multiple stressors on the structure of benthic communities. It will also eventually contribute to species conservation and the management of maritime resources.

scholarly journals Cumulative impacts of anthropogenic stressors on macrobenthic communities at a bay-scale: an experimental approach

2018 ◽  
Author(s):  
Charlotte Carrier-Belleau ◽  
Philippe Archambault ◽  
Christopher W. McKindsey
Keyword(s):  
Experimental Approach ◽  
Multiple Stressors ◽  
Benthic Communities ◽  
Species Conservation ◽  
Environmental Stressors ◽  
Cumulative Impacts ◽  
Anthropogenic Stressors ◽  
Biological Responses ◽  
Manipulative Experiments

Human activities such as maritime transport, fishing and aquaculture create environmental stressors affecting the structure and the functioning of benthic communities. While these disturbances can act individually, they can also act synergistically and lead to changes more difficult to predict. The bay of Sept-Îles hosts a harbour receiving the most important ballast volume in North America and represents one of the most eutrophic bays in the Gulf of St. Lawrence. This project is part of the Canadian healthy oceans network (CHONe II) and attempts to identify the effect of the interaction of anthropogenic stressors on the macrobenthic invertebrate communities in the bay of Sept-Îles. In situ and laboratory manipulative experiments will be conducted to determine the influence of stressors on biological responses when taken individually, and when these stressors interact through time at different intensities. In that way, these experiments will improve our knowledge of cumulated impacts of multiple stressors on the structure of benthic communities. It will also eventually contribute to species conservation and the management of maritime resources.

scholarly journals Multiple mechanisms in which agricultural insects respond to environmental stressors: canalization, plasticity and evolution

2020 ◽  
Vol 37 (1) ◽  
pp. 90-99
Author(s):  
Yeisson Gutiérrez
Keyword(s):  
Multiple Stressors ◽  
Short Review ◽  
Environmental Stressors ◽  
Negative Consequences ◽  
Ecological Functions ◽  
Policy Makers ◽  
Future Studies ◽  
Manipulative Experiments ◽  
Insect Biology ◽  
Insect Decline

Insects are a paramount component of biodiversity in terms of taxonomic richness, ecological functions and ecosystem services. However, many human activities have negative consequences on such organisms, causing changes in their morphology, physiology, behaviour, and even causing mass deaths leading to the well-recognized insect decline phenomenon. Although the effects of some environmental stressors (e.g. global warming and pesticides) on insect biology are fairly well understood, there is a plethora of stressors that that have only recently been considered. Additionally, although the exposure to multiple stressors is a common scenario in natural conditions, our knowledge on insect responses in this regard is still incipient. Knowledge that is in much need to inform policy makers in the fight against global change. Here, a short review on prominent environmental stressors, and the known responses that insects may exhibit, which are summarized as canalization, plasticity and evolution is provided. Furthermore, an outlook and recommendation for future studies aiming to elucidate the effects of environmental stressors (both lone and mixed) on insect biology is given. This manuscript advocates for controlled (lab or semi-field) manipulative experiments that implement realistic environmental conditions and that ideally combine several stressors.

scholarly journals Environmental stressors, complex interactions and marine benthic communities’ responses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charlotte Carrier-Belleau ◽  
David Drolet ◽  
Christopher W. McKindsey ◽  
Philippe Archambault
Keyword(s):  
Nutrient Enrichment ◽  
Multiple Stressors ◽  
Energy Content ◽  
Benthic Communities ◽  
Ecosystem Functions ◽  
Salinity Variation ◽  
Complex Interactions ◽  
Marine Habitats ◽  
Biological Responses ◽  
Negative Impacts

AbstractThe increasing number and diversity of anthropogenic stressors in marine habitats have multiple negative impacts on biological systems, biodiversity and ecosystem functions. Methods to assess cumulative effects include experimental manipulations, which may identify non-linear responses (i.e. synergies, antagonisms). However, experiments designed to test these ideas are uncommon, generally focusing on single biological responses. We conducted a manipulative experiment to investigate the isolated and combined effects of warming (+ 6 °C), salinity variation (freshwater pulses or presses), and nutrient enrichment (natural or enriched) following one and three month’s exposure, on responses measured at multiple levels of biological complexity in a simple bivalve assemblage. More specifically, we determined effects on bivalve mortality, growth, shell mineralization, and energy content, as well as microphytobenthos biomass. Salinity variation and nutrient enrichment, individually and combined, caused strong impacts on some of the measured variables and their effect varied through time. In contrast, warming had no effect. Our work highlights the prevalence of antagonistic interactions, the importance of examining effects of single and multiple stressors through time, and of considering multiple responses to understand the complexity behind stressor interactions.

Synergistic interactions of biotic and abiotic environmental stressors on gene expression

Genome ◽  
2015 ◽  
Vol 58 (3) ◽  
pp. 99-109 ◽  
Author(s):  
Ianina Altshuler ◽  
Anne M. McLeod ◽  
John K. Colbourne ◽  
Norman D. Yan ◽  
Melania E. Cristescu
Keyword(s):  
Gene Expression ◽  
Calcium Concentration ◽  
Multiple Stressors ◽  
Expression Patterns ◽  
Environmental Stressors ◽  
Calcium Pump ◽  
Synergistic Interactions ◽  
Anthropogenic Stressors ◽  
Low Calcium ◽  
Cuticle Proteins

Understanding the response of organisms to multiple stressors is critical for predicting if populations can adapt to rapid environmental change. Natural and anthropogenic stressors often interact, complicating general predictions. In this study, we examined the interactive and cumulative effects of two common environmental stressors, lowered calcium concentration, an anthropogenic stressor, and predator presence, a natural stressor, on the water flea Daphnia pulex. We analyzed expression changes of five genes involved in calcium homeostasis — cuticle proteins (Cutie, Icp2), calbindin (Calb), and calcium pump and channel (Serca and Ip3R) — using real-time quantitative PCR (RT-qPCR) in a full factorial experiment. We observed strong synergistic interactions between low calcium concentration and predator presence. While the Ip3R gene was not affected by the stressors, the other four genes were affected in their transcriptional levels by the combination of the stressors. Transcriptional patterns of genes that code for cuticle proteins (Cutie and Icp2) and a sarcoplasmic calcium pump (Serca) only responded to the combination of stressors, changing their relative expression levels in a synergistic response, while a calcium-binding protein (Calb) responded to low calcium stress and the combination of both stressors. The expression pattern of these genes (Cutie, Icp2, and Serca) were nonlinear, yet they were dose dependent across the calcium gradient. Multiple stressors can have complex, often unexpected effects on ecosystems. This study demonstrates that the dominant interaction for the set of tested genes appears to be synergism. We argue that gene expression patterns can be used to understand and predict the type of interaction expected when organisms are exposed simultaneously to natural and anthropogenic stressors.

scholarly journals Glacial melt disturbance shifts community metabolism of an Antarctic seafloor ecosystem from net autotrophy to heterotrophy

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ulrike Braeckman ◽  
Francesca Pasotti ◽  
Ralf Hoffmann ◽  
Susana Vázquez ◽  
Angela Wulff ◽  
...  
Keyword(s):  
Carbon Balance ◽  
Benthic Communities ◽  
Benthic Primary Production ◽  
Community Metabolism ◽  
West Antarctic ◽  
Run Off ◽  
Net Heterotrophy ◽  
Benthic Ecosystems ◽  
The Antarctic

AbstractClimate change-induced glacial melt affects benthic ecosystems along the West Antarctic Peninsula, but current understanding of the effects on benthic primary production and respiration is limited. Here we demonstrate with a series of in situ community metabolism measurements that climate-related glacial melt disturbance shifts benthic communities from net autotrophy to heterotrophy. With little glacial melt disturbance (during cold El Niño spring 2015), clear waters enabled high benthic microalgal production, resulting in net autotrophic benthic communities. In contrast, water column turbidity caused by increased glacial melt run-off (summer 2015 and warm La Niña spring 2016) limited benthic microalgal production and turned the benthic communities net heterotrophic. Ongoing accelerations in glacial melt and run-off may steer shallow Antarctic seafloor ecosystems towards net heterotrophy, altering the metabolic balance of benthic communities and potentially impacting the carbon balance and food webs at the Antarctic seafloor.

Estimating thermo-osmotic coefficients in clay-rocks: II. In situ experimental approach

2010 ◽  
Vol 342 (1) ◽  
pp. 175-184 ◽  
Author(s):  
J. Trémosa ◽  
J. Gonçalvès ◽  
J.M. Matray ◽  
S. Violette
Keyword(s):  
Experimental Approach ◽  
Osmotic Coefficients ◽  
Clay Rocks

In situ Enclosure Experiment Using a Benthic Chamber System to Assess the Effect of High Concentration of CO2 on Deep-Sea Benthic Communities

2005 ◽  
Vol 61 (5) ◽  
pp. 835-843 ◽  
Author(s):  
Hiroshi Ishida ◽  
Yuji Watanabe ◽  
Tatsuo Fukuhara ◽  
Sho Kaneko ◽  
Kazushi Furusawa ◽  
...  
Keyword(s):  
Deep Sea ◽  
Benthic Communities ◽  
Chamber System ◽  
High Concentration ◽  
Enclosure Experiment ◽  
Benthic Chamber

scholarly journals Experimental approach to overexpress pituitary adenylate cyclase activating polypeptide (PACAP) specifically in the hypothalamus

2021 ◽  
Author(s):  
◽  
Yamna Rahim
Keyword(s):  
Energy Expenditure ◽  
Experimental Approach ◽  
Health Condition ◽  
Specific Expression ◽  
Steroidogenic Factor 1 ◽  
Adaptive Thermogenesis ◽  
Brown Adipose ◽  
Pituitary Adenylate Cyclase ◽  
The Brain

Obesity is adetrimental health condition that occurs when energy intake, exceeds energy expenditure. Pituitary adenylatecyclase-activating polypeptide (PACAP) regulates energy expenditure, including adaptive thermogenesis, through the hypothalamic-sympatheticnervous system-brown adipose tissue axis. We hypothesize that PACAP expression in the ventromedial nucleus (VMN) is required for adaptive thermogenesis. To assess this, our goal is to develop an animal model that expresses PACAP specifically in the VMN of the hypothalamus. As a first step to achieving this goal, we established a protocol to deliver an adeno-associatedvirus (AAV) expressing the visible protein eGFP under the control of a VMN-specific promoter, steroidogenic factor 1 (SF1) using stereotaxic surgery. A second step was to develop a protocol to detect PACAP mRNA in the brain using in situ hybridization. Our results showed that the stereotaxic protocol was successful and provides significant progress towards achieving PACAP-specific expression in the VMN.

scholarly journals In situ filamentous communities from the Ediacaran (approx. 563 Ma) of Brazil

2021 ◽  
Vol 288 (1942) ◽  
pp. 20202618
Author(s):  
Bruno Becker-Kerber ◽  
Gabriel Eduardo Baréa de Barros ◽  
Paulo Sergio Gomes Paim ◽  
Gustavo M. E. M. Prado ◽  
Ana Lucia Zucatti da Rosa ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Benthic Communities ◽  
Preferred Orientation ◽  
Redox Condition ◽  
Taxonomic Assignment ◽  
Diagnostic Features ◽  
Ecological Dynamics ◽  
Widespread Occurrence ◽  
Biological Affinity

Precambrian filamentous microfossils are common and diverse. Nevertheless, their taxonomic assignment can be difficult owing to their overall simple shapes typically lacking in diagnostic features. Here, we report in situ communities of well-preserved, large filamentous impressions from the Ediacaran Itajaí Basin ( ca 563 Ma) of Brazil. The filaments are uniserial (unbranched) and can reach up to 200 µm in width and up to 44 mm in length. They occur as both densely packed or sparsely populated surfaces, and typically show a consistent orientation. Although simple in shape, their preferred orientation suggests they were tethered to the seafloor, and their overall flexibility (e.g. bent, folded and twisted) supports a biological (rather than sedimentary) affinity. Biometric comparisons with modern filamentous groups further support their biological affinity, suggesting links with either large sulfide-oxidizing bacteria (SOB) or eukaryotes. Other morphological and palaeoecological characteristics further corroborates their similarities with modern large filamentous SOB. Their widespread occurrence and association with complex Ediacaran macrobiota (e.g. frondose organisms, Palaeopascichnus ) suggest that they probably played an important role in the ecological dynamics of these early benthic communities by providing firm substrates for metazoans to inhabit. It is further hypothesized that the dynamic redox condition in the latest Ediacaran, with the non-continuous rise in oxygen concentration and periods of hypoxia, may have created ideal conditions for SOB to thrive.

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