scholarly journals The diet of reservoir perch before, during and after establishment of non-native tubenose goby

2018 ◽  
pp. 4 ◽  
Author(s):  
Lucie Všetičková ◽  
Libor Mikl ◽  
Zdeněk Adámek ◽  
Václav Prášek ◽  
Kevin Roche ◽  
...  
Keyword(s):  
Food Web ◽  
Littoral Zone ◽  
Diet Composition ◽  
Prey Species ◽  
Perca Fluviatilis ◽  
Tubenose Goby ◽  
Increasing Trend ◽  
Lowland Reservoir ◽  
Proterorhinus Semilunaris

In recent decades, gobiid species have increased their distribution throughout Europe and now often represent the dominant genus along many rivers and canals. In this study, we assessed the role of tubenose goby (Proterorhinus semilunaris) as a prey species of native perch (Perca fluviatilis) in a lowland reservoir soon after their initial introduction in 1994 (sampling started 1998) and 17 years after establishment (2011–2012). We compare these data with perch diet composition from before introduction (1981–1982). Our data indicate that tubenose gobies quickly became the dominant species along the reservoir bankside, making them an attractive prey for ≥1 + perch. There was a clear increasing trend in the numbers of larger perch caught along the rip-rap, with the largest fish clearly specialising on gobies. As such, introduction of tubenose gobies has had a pronounced effect on food web and population dynamics along the littoral zone. While goby numbers appear to have dropped significantly in recent years, apparently due to predation pressure, further studies are needed to assess whether such changes have had any general impact on population and food web dynamics within the reservoir.

scholarly journals Eye fluke infection changes diet composition in juvenile European perch (Perca fluviatilis)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jenny C. Vivas Muñoz ◽  
Christian K. Feld ◽  
Sabine Hilt ◽  
Alessandro Manfrin ◽  
Milen Nachev ◽  
...  
Keyword(s):  
Diet Composition ◽  
Infection Intensity ◽  
Perca Fluviatilis ◽  
Trophic Levels ◽  
Fish Diet ◽  
European Perch ◽  
Diet Specialization ◽  
Fluke Infection ◽  
Eye Fluke

AbstractIntraspecific diet specialization, usually driven by resource availability, competition and predation, is common in natural populations. However, the role of parasites on diet specialization of their hosts has rarely been studied. Eye flukes can impair vision ability of their hosts and have been associated with alterations of fish feeding behavior. Here it was assessed whether European perch (Perca fluviatilis) alter their diet composition as a consequence of infection with eye flukes. Young-of-the-year (YOY) perch from temperate Lake Müggelsee (Berlin, Germany) were sampled in two years, eye flukes counted and fish diet was evaluated using both stomach content and stable isotope analyses. Perch diet was dominated by zooplankton and benthic macroinvertebrates. Both methods indicated that with increasing eye fluke infection intensity fish had a more selective diet, feeding mainly on the benthic macroinvertebrate Dikerogammarus villosus, while less intensively infected fish appeared to be generalist feeders showing no preference for any particular prey type. Our results show that infection with eye flukes can indirectly affect interaction of the host with lower trophic levels by altering the diet composition and highlight the underestimated role of parasites in food web studies.

Foreign Labour Migration, Economic Growth and Remittances in Nepal

Patan Pragya ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 122-132
Author(s):  
Laxman Singh Kunwer
Keyword(s):  
Working Environment ◽  
Labour Migration ◽  
Sources Of Information ◽  
Pull Factors ◽  
Push And Pull Factors ◽  
Secondary Sources ◽  
Foreign Labour ◽  
Increasing Trend ◽  
Push And Pull

This paper examines the history and current situation of foreign labour migration in Nepal, which is in increasing trend. This paper highlights on some major push and pull factors, impacts of labour migration and remittances. The role and impacts of remittances in Nepal are also another key issue of this paper. The objective of paper is to discuss historical aspects and highlights the role of remittances in Nepal. The paper is developed with the help of secondary sources of information and discussed only on Nepalese foreign labours. The existing exploitative working environment in destinations of Nepalese migrations labpurs, lack of skills and trainings among labour migrants including government to government agreement between labour sending (Nepal) and labour receiving countries to protect rights of labour migrants also has been discussed. This paper also highlights the need of effective foreign labour policies based on scientific research. There is need of reliable and proper environment of investment of remittances in productive sectors as well as use of migrant's skills and knowledge to achieve prosperity of nation.

scholarly journals Trends and Clinico-Epidemiological Features of Human Rabies Cases in Bangladesh, 2006–2018

2020 ◽  
Vol 41 (S1) ◽  
pp. s416-s416
Author(s):  
Sumon Ghosh ◽  
Md. Sohel Rana ◽  
Sukanta Chowdhury
Keyword(s):  
Effective Means ◽  
Scale Up ◽  
Traditional Healers ◽  
Human Rabies ◽  
Epidemiological Analysis ◽  
Increasing Trend ◽  
The Mean ◽  
Death Cases ◽  
Death Data

Background: Vaccinating dogs against rabies is an effective means of reducing human rabies. Methods: We analyzed 1,327 clinically diagnosed human rabies deaths and mass dog vaccination (MDV) data during 2006–2018 to quantify the impacts of MDV on human rabies incidence in Bangladesh and a subset of rabies death data (n = 422) for clinico-epidemiological analysis. Results: We found a positive and increasing trend of dog population vaccination (P = .01 and τ = 0.71) and a negative and declining trend (P < .001 and τ = −0.88) of human rabies cases (correlation coefficient, −0.82). Among 422 human rabies death cases, most victims (78%) sought treatment from traditional healers, and 12% received postexposure prophylaxis (PEP). The mean incubation period of rabies cases with exposure sites on the head and neck (35 days) was shorter than the upper limb (mean, 64 days; P = .02) and lower limb (mean, 89 days; P < .01). MDV is effective for reducing human rabies cases in Bangladesh. Conclusions: Creating awareness among the animal bite victims to stop relying on traditional healers rather seeking PEP, addressing the role of traditional healers through an awareness education program in respect to the treatment of dog bites, ensuring availability of PEP, and continuing to scale up MDV can help prevent human rabies deaths.Funding: NoneDisclosures: None

scholarly journals A review of public acceptance of nature-based solutions: The ‘why’, ‘when’, and ‘how’ of success for disaster risk reduction measures

AMBIO ◽  
2021 ◽  
Author(s):  
Carl C. Anderson ◽  
Fabrice G. Renaud
Keyword(s):  
Ecosystem Services ◽  
Risk Perception ◽  
Risk Reduction ◽  
Disaster Risk Reduction ◽  
Disaster Risk ◽  
Public Acceptance ◽  
Societal Challenges ◽  
Increasing Trend ◽  
Risk Reduction Measures

AbstractNature-based solutions (NbS) are increasingly recognized as sustainable approaches to address societal challenges. Disaster risk reduction (DRR) has benefited by moving away from purely ‘grey’ infrastructure measures towards NbS. However, this shift also furthers an increasing trend of reliance on public acceptance to plan, implement and manage DRR measures. In this review, we examine how unique NbS characteristics relate to public acceptance through a comparison with grey measures, and we identify influential acceptance factors related to individuals, society, and DRR measures. Based on the review, we introduce the PA-NbS model that highlights the role of risk perception, trust, competing societal interests, and ecosystem services. Efforts to increase acceptance should focus on providing and promoting awareness of benefits combined with effective communication and collaboration. Further research is required to understand interconnections among identified factors and how they can be leveraged for the success and further uptake of NbS.

The Role of Ammonites in the Mesozoic Marine Food Web Revealed by Jaw Preservation

Science ◽  
2011 ◽  
Vol 331 (6013) ◽  
pp. 70-72 ◽  
Author(s):  
I. Kruta ◽  
N. Landman ◽  
I. Rouget ◽  
F. Cecca ◽  
P. Tafforeau
Keyword(s):  
Food Web ◽  
Marine Food Web ◽  
Marine Food

Seasonal and between-year variations in the diet of harbour seals in the Moray Firth, Scotland

1996 ◽  
Vol 74 (6) ◽  
pp. 1110-1121 ◽  
Author(s):  
D. J. Tollit ◽  
P. M. Thompson
Keyword(s):  
Diet Composition ◽  
Gadus Morhua ◽  
Prey Species ◽  
Temporal Variations ◽  
Short Term ◽  
Harbour Seals ◽  
Faecal Samples ◽  
Poor Indicator ◽  
Moray Firth ◽  
Merlangius Merlangus

Predictions concerning the effect of seals upon prey stocks require an understanding of temporal variations in diet composition. This study examined the extent of between-year and seasonal variations in the diet of harbour seals (Phoca vitulina) from the Moray Firth, Scotland, between 1989 and 1992. Analyses of fish otoliths and cephalopod beaks collected from 1129 faecal samples were used to derive estimates of the contribution made by each of 35 prey species, based on the number and mass consumed. The key prey, by mass, were sand eels (Ammodytidae) (47%), lesser octopus (Eledone cirrhosa) (27%), whiting (Merlangius merlangus) (6%), flounder (Platichthys flesus) (5%), and cod (Gadus morhua) (4%). Between-year and seasonal fluctuations in the contributions of these species were observed. Sand eels contributed 86–20% in summer and 91–49% in winter. Lesser octopus contributed 0–62% in summer and < 5% in winter, whilst whiting and cod contributed 2–34% in winter and 1–4% in summer. In contrast to 1988, clupeids were unimportant in winter. Differences in diet composition appeared to reflect local changes in the availability of food, especially overwintering clupeids. Results indicate that dietary information obtained from short-term studies can be a poor indicator of subsequent diet composition and should be treated with caution when used to predict the effect of seals on prey populations.

Ecology of terrace wet rice-fish environment and role of periphyton

2011 ◽  
Vol 4 ◽  
pp. 102-111 ◽  
Author(s):  
Surjya Kumar Saikia ◽  
Debangshu Narayan Das
Keyword(s):  
Rice Fields ◽  
The North ◽  
North Eastern ◽  
Increasing Trend ◽  
The Rich ◽  
Carbon Dioxide Co2 ◽  
Rice Fish ◽  
Water Canals ◽  
Key Words Rice

The waterlogged terrace wet rice-fields of Apatani Plateau located at an altitude of 1500msl in Arunachal Pradesh of the north eastern India are stocked with fish Common carp (Cyprinus carpio L) for several decades. The fishes are not fed with supplementary feeds because of the rich organic nature of the rice-fields. The study on water and soil of these fields revealed a strong co-relation to such organic nature. The wet rice-fish integrated fields exhibited the characters of shallow wet ecosystems. The water canals traversed through the rice fields were found inundated with water up to 50m showing the nature of Deep Water Rice fields (DWR) at least for one month. Significant (p<0.001) variations of water were observed for dissolved oxygen (DO) and carbon dioxide (CO2) to diurnal and seasonal changes. Alkalinity of the fields intends to play a role towards its productivity which is otherwise played by DO in other aquatic systems. Soil nitrogen reflected a gradual increasing trend of organic nature. Role of periphyton may not be ignored to the high phosphorus level of the soil at later flood phases in these fields. Key words: Rice-fish; aquatic ecosystem; organic practice; plankton; periphyton DOI: 10.3126/jowe.v4i0.2585Journal of Wetlands Ecology, (2010) Vol. 4, pp 102-111

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