scholarly journals Environmental requirements and heterogeneity of rheophilic fish nursery habitats in European lowland rivers: Current insights and future challenges

2021 ◽  
Author(s):  
Twan Stoffers ◽  
Antonie D. Buijse ◽  
Johan A. J. Verreth ◽  
Leopold A. J. Nagelkerke
Keyword(s):  
Lowland Rivers ◽  
Fish Nursery ◽  
Nursery Habitats ◽  
Future Challenges ◽  
Environmental Requirements ◽  
Rheophilic Fish

Size-selective predation by river otter (Lontra canadensis) improves refuge properties of shallow coastal marine nursery habitats

2008 ◽  
Vol 86 (11) ◽  
pp. 1324-1328 ◽  
Author(s):  
D. Cote ◽  
R. S. Gregory ◽  
H. M.J. Stewart
Keyword(s):  
Shallow Water ◽  
Atlantic Cod ◽  
Prey Availability ◽  
Juvenile Fish ◽  
Lontra Canadensis ◽  
River Otter ◽  
Fish Nursery ◽  
Piscivorous Fish ◽  
Risk Of Predation ◽  
Nursery Habitats

Young fish often avoid deep water to reduce predation risk from larger fish. Less clear are explanations for the avoidance of shallows by large piscivorous fish; however, one hypothesis suggests that this distribution reduces contact with depth-limited semi-aquatic mammal and bird piscivores. We determined prey size selection of the river otter ( Lontra canadensis (Schreber, 1777)) to test the hypothesis that larger fish are at elevated risk in shallow coastal waters in Newman Sound, Newfoundland, during June–November 2001 and May 2002. We compared otter diet (scat analysis) and prey availability (seine sampling) to test this hypothesis. Five fish taxa (Atlantic cod ( Gadus morhua L., 1758), Greenland cod ( Gadus ogac Richardson, 1836), shorthorn sculpin ( Myoxocephalus scorpius (L., 1758)), cunner ( Tautogolabrus adspersus (Walbaum, 1792)), and winter flounder ( Pseudopleuronectes americanus (Walbaum, 1792))) dominated the shallow-water fish community and were sufficiently abundant in otter scats to examine feeding preferences. Larger, piscivorous fish were selected by otters, suggesting that they were at greater risk of predation than smaller fish, consistent with our hypothesis that depth-limited, diurnally active predators restrict large fish from hunting in shallow water during daytime. We suggest that depth-limited air-breathing predators may reduce the presence of such predatory fish in shallow-water juvenile fish nursery habitats.

scholarly journals Acute embryonic anoxia exposure favours the development of a dominant and aggressive phenotype in adult zebrafish

2017 ◽  
Vol 284 (1846) ◽  
pp. 20161868 ◽  
Author(s):  
Catherine M. Ivy ◽  
Cayleih E. Robertson ◽  
Nicholas J. Bernier
Keyword(s):  
Social Interactions ◽  
Later Life ◽  
Mirror Image ◽  
Developmental Trajectory ◽  
Fish Nursery ◽  
Aggressive Phenotype ◽  
Basal Cortisol ◽  
Stress Responsiveness ◽  
Nursery Habitats ◽  
Cortisol Levels

Eutrophication and climate change are increasing the incidence of severe hypoxia in fish nursery habitats, yet the programming effects of hypoxia on stress responsiveness in later life are poorly understood. In this study, to investigate whether early hypoxia alters the developmental trajectory of the stress response, zebrafish embryos were exposed to 4 h of anoxia at 36 h post-fertilization and reared to adults when the responses to secondary stressors were assessed. While embryonic anoxia did not affect basal cortisol levels or the cortisol response to hypoxia in later life, it had a marked effect on the responses to a social stressor. In dyadic social interactions, adults derived from embryonic anoxia initiated more chases, bit more often, entered fewer freezes and had lower cortisol levels. Adults derived from embryonic anoxia also performed more bites towards their mirror image, had lower gonadal aromatase gene expression and had higher testosterone levels. We conclude that acute embryonic anoxia has long-lasting consequences for the hormonal and behavioural responses to social interactions in zebrafish. Specifically, we demonstrate that acute embryonic anoxia favours the development of a dominant and aggressive phenotype, and that a disruption in sex steroid production may contribute to the programming effects of environmental hypoxia.

TWENTY-FIVE YEARS OF EIA IN GERMANY: OUR CHILD HAS GROWN UP

2012 ◽  
Vol 14 (04) ◽  
pp. 1250023 ◽  
Author(s):  
WOLFGANG WENDE ◽  
FRANK SCHOLLES ◽  
JOACHIM HARTLIK
Keyword(s):  
Decision Making ◽  
Environmental Planning ◽  
Current Status ◽  
Future Challenges ◽  
Environmental Requirements ◽  
New Challenges ◽  
Further Development ◽  
Over Time ◽  
Area Of Application ◽  
The Eu

Environmental Impact Assessment (EIA) has been formally applied in Germany since 1990, and has over time developed a methodological and technical routine in environmental planning practice. It can now be considered an established instrument; nonetheless, substantial challenges to the further development of the EIA, and to even stronger implementation of environmental requirements in planning and decision-making practice in Germany, still exist. This paper reports briefly on the application and the main achievements of the EIA in Germany, and, in the second section, primarily provides a perspective for addressing remaining and new challenges involving this instrument. The paper also includes specific proposals for the further optimization of the EIA at the EU level, as well as for Germany. The current status and future challenges facing the EIA, which are described herein, range from screening and scoping through public participation and monitoring to the area of application.

Rheophilic fish in oxbow lakes of the Warta River – the effect of environmental conditions on habitat selection

2017 ◽  
Vol 46 (1) ◽  
Author(s):  
Janusz Golski ◽  
Piotr Pińskwar ◽  
Maria Jezierska-Madziar ◽  
Wojciech Andrzejewski ◽  
Jan Mazurkiewicz ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Relative Abundance ◽  
Environmental Conditions ◽  
Water Bodies ◽  
Oxbow Lakes ◽  
Dominance Structure ◽  
Environmental Requirements ◽  
Reproductive Guild ◽  
Rheophilic Fish ◽  
Natural Rivers

AbstractOxbow lakes are typical elements of meandering watercourses and are considered to be key components of floodplains of natural rivers. A permanent connection with the river promotes the use of these water bodies by ichthyofauna as spawning grounds, shelter for fry, feeding and wintering grounds. The aim of this study was to determine which rheophilic species inhabit oxbow lakes and how environmental conditions affect habitat selection and fish behavior. Analyses were conducted on six oxbow lakes of the Warta River in the Koło-Poznań section. Fish and water samples were collected for three years, in spring, summer and late autumn. Variation in environmental conditions in the analyzed water bodies results in a considerable diversity of the ichthyofauna, including rheophilic species, in individual seasons of the year. In the course of the study, nine rheophilic fish species were recorded, including four from the lithophilic reproductive guild having the highest environmental requirements. Relative abundance of rheophilic species in the dominance structure ranged from 0 to 100%, depending on the reservoir and seasons, with an average of 7% for all catches. For comparison, their relative abundance in the adjacent parts of the river was 12 and 23%.

International evaluation of current and future requirements for environmental engineering education

2004 ◽  
Vol 49 (8) ◽  
pp. 11-18 ◽  
Author(s):  
E. Morgenroth ◽  
G.T. Daigger ◽  
A. Ledin ◽  
J. Keller
Keyword(s):  
Engineering Education ◽  
Interdisciplinary Teams ◽  
Environmental Engineering ◽  
Current Status ◽  
Engineering Profession ◽  
Science And Society ◽  
Engineering Problems ◽  
Future Challenges ◽  
Fundamental Education ◽  
Environmental Requirements

The field of environmental engineering is developing as a result of changing environmental requirements. In response, environmental engineering education (E3) needs to ensure that it provides students with the necessary tools to address these challenges. In this paper the current status and future development of E3 is evaluated based on a questionnaire sent to universities and potential employers of E3 graduates. With increasing demands on environmental quality, the complexity of environmental engineering problems to be solved can be expected to increase. To find solutions environmental engineers will need to work in interdisciplinary teams. Based on the questionnaire there was a broad agreement that the best way to prepare students for these future challenges is to provide them with a fundamental education in basic sciences and related engineering fields. Many exciting developments in the environmental engineering profession will be located at the interface between engineering, science, and society. Aspects of all three areas need to be included in E3 and the student needs to be exposed to the tensions associated with linking the three.

Predation on small juvenile fishes in shallow estuarine nursery areas: Reply to Baker & Sheaves (2021)

2021 ◽  
Vol 662 ◽  
pp. 209-214
Author(s):  
A Whitfield
Keyword(s):  
South Africa ◽  
Juvenile Fish ◽  
Fish Predation ◽  
Estuarine Waters ◽  
Fish Nursery ◽  
Piscivorous Fish ◽  
Small Juvenile ◽  
Nursery Habitats ◽  
High Predation ◽  
Counter Argument

The key criticism by Baker & Sheaves (2021; Mar Ecol Prog Ser 662:205-208) of the Whitfield (2020; Mar Ecol Prog Ser 649:219-234) estuarine littoral predation paradigm review is that shallow water fish nursery habitats contain abundant predator assemblages which may create high predation pressure on the juvenile fish cohorts that occupy these areas. The primary arguments supporting Baker & Sheaves’ criticism arise from a series of papers published by them on piscivorous fish predation in certain tropical Australian estuaries. The counter-argument that shallow littoral areas in estuaries do indeed provide small juvenile fishes with refuge from small and large piscivorous fishes is provided by published papers from 4 different estuary types in South Africa, covering both subtropical and warm-temperate systems. Based on the overall published information, the argument for shallow (<1 m depth) estuarine waters providing major protection for newly settled juveniles appears to be weak in northern Australia but strong in South Africa. The global situation, as outlined in this response, is more supportive of low piscivorous predation in shallow nursery habitats, but further targeted research is needed before we can confirm that littoral estuarine waters are indeed a universal keystone attribute in this regard.

scholarly journals Linking habitat mosaics and connectivity in a coral reef seascape

2012 ◽  
Vol 109 (38) ◽  
pp. 15372-15376 ◽  
Author(s):  
Kelton W. McMahon ◽  
Michael L. Berumen ◽  
Simon R. Thorrold
Keyword(s):  
Coral Reef ◽  
Global Scale ◽  
Habitat Destruction ◽  
Anthropogenic Pressure ◽  
Fish Nursery ◽  
Habitat Mosaics ◽  
Migration Corridors ◽  
Direct Measurements ◽  
Nursery Habitats ◽  
And Function

Tropical marine ecosystems are under mounting anthropogenic pressure from overfishing and habitat destruction, leading to declines in their structure and function on a global scale. Although maintaining connectivity among habitats within a seascape is necessary for preserving population resistance and resilience, quantifying movements of individuals within seascapes remains challenging. Traditional methods of identifying and valuing potential coral reef fish nursery habitats are indirect, often relying on visual surveys of abundance and correlations of size and biomass among habitats. We used compound-specific stable isotope analyses to determine movement patterns of commercially important fish populations within a coral reef seascape. This approach allowed us to quantify the relative contributions of individuals from inshore nurseries to reef populations and identify migration corridors among important habitats. Our results provided direct measurements of remarkable migrations by juvenile snapper of over 30 km, between nurseries and reefs. We also found significant plasticity in juvenile nursery residency. Although a majority of individuals on coastal reefs had used seagrass nurseries as juveniles, many adults on oceanic reefs had settled directly into reef habitats. Moreover, seascape configuration played a critical but heretofore unrecognized role in determining connectivity among habitats. Finally, our approach provides key quantitative data necessary to estimate the value of distinctive habitats to ecosystem services provided by seascapes.

scholarly journals Shining a light on the loss of rheophilic fish habitat in lowland rivers as a forgotten consequence of barriers, and its implications for management

2017 ◽  
Vol 27 (6) ◽  
pp. 1345-1349 ◽  
Author(s):  
Kim Birnie-Gauvin ◽  
Kim Aarestrup ◽  
Thorsten M.O. Riis ◽  
Niels Jepsen ◽  
Anders Koed
Keyword(s):  
Fish Habitat ◽  
Lowland Rivers ◽  
Rheophilic Fish

ACE2 as therapeutic agent

2020 ◽  
Vol 134 (19) ◽  
pp. 2581-2595
Author(s):  
Qiuhong Li ◽  
Maria B. Grant ◽  
Elaine M. Richards ◽  
Mohan K. Raizada
Keyword(s):  
Therapeutic Agent ◽  
Renin Angiotensin System ◽  
Peptide Hormone ◽  
Experimental Models ◽  
Electrolyte Balance ◽  
Ang Ii ◽  
Angiotensin Converting Enzyme 2 ◽  
Beneficial Effects ◽  
Overwhelming Evidence ◽  
Future Challenges

Abstract The angiotensin-converting enzyme 2 (ACE2) has emerged as a critical regulator of the renin–angiotensin system (RAS), which plays important roles in cardiovascular homeostasis by regulating vascular tone, fluid and electrolyte balance. ACE2 functions as a carboxymonopeptidase hydrolyzing the cleavage of a single C-terminal residue from Angiotensin-II (Ang-II), the key peptide hormone of RAS, to form Angiotensin-(1-7) (Ang-(1-7)), which binds to the G-protein–coupled Mas receptor and activates signaling pathways that counteract the pathways activated by Ang-II. ACE2 is expressed in a variety of tissues and overwhelming evidence substantiates the beneficial effects of enhancing ACE2/Ang-(1-7)/Mas axis under many pathological conditions in these tissues in experimental models. This review will provide a succinct overview on current strategies to enhance ACE2 as therapeutic agent, and discuss limitations and future challenges. ACE2 also has other functions, such as acting as a co-factor for amino acid transport and being exploited by the severe acute respiratory syndrome coronaviruses (SARS-CoVs) as cellular entry receptor, the implications of these functions in development of ACE2-based therapeutics will also be discussed.

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