The Role of the Neighbourhood in Rehabilitation of an Urban Aquatic Ecosystem

1997 ◽  
Vol 32 (2) ◽  
pp. 245-256 ◽  
Author(s):  
K.W. Dance
Keyword(s):  
Fish Species ◽  
Exotic Fish ◽  
Positive Role ◽  
Management Intervention ◽  
Rehabilitation Plan ◽  
Management Interventions ◽  
Periodic Monitoring ◽  
Exotic Fish Species

Abstract For the first 10 to 15 years following rehabilitation, the original goals at West Heights Pond, Kitchener, were attained. Monitoring over a 16-year period revealed that if ecosystem health and aesthetics goals are to be sustained in the future, management intervention is required. Required management includes on-going control of aggressive wetland plant pests; efforts to discourage waterfowl feeding so that numbers decline and water quality improves; and potential future control of exotic fish species goldfish and carp. The study has concluded that (1) periodic monitoring over the long term is required to determine whether rehabilitation plan goals are being met and to identify the nature of required management interventions; (2) human neighbours are a critical species in the ecosystem management process since they can be the agents of significant positive and negative actions which affect attainment of rehabilitation plan goals; and (3) the lead agency in rehabilitation implementation should ensure that a long-term dialogue with site neighbours capitalizes on the positive role neighbours can play and avoids negative actions such as feeding waterfowl, trampling banks and vegetation, and introducing exotic fish species.

scholarly journals Long-term fish monitoring underlines a rising tide of temperature tolerant, rheophilic, benthivore and generalist exotics, irrespective of hydrological conditions

2018 ◽  
Vol 77 (2) ◽  
Author(s):  
Marco Milardi ◽  
Mattia Lanzoni ◽  
Anna Gavioli ◽  
Elisa Anna Fano ◽  
Giuseppe Castaldelli
Keyword(s):  
Fish Species ◽  
Species Interactions ◽  
Native Species ◽  
Control Strategies ◽  
Exotic Fish ◽  
Po River ◽  
Clear Trend ◽  
Current Conservation ◽  
Exotic Fish Species

The invasion of exotic species is one of the main threats to worldwide biodiversity and can be aided by changes in environmental conditions. We hypothesized that a temporal trend of decreasing discharge and increasing temperature might have favored the invasion of warm-adapted, lentic exotic fish species in the lower Po River, northern Italy. We used presence/absence data over a long-term period (over 20 years) to investigate the dynamics of exotic fish invasion along water temperature and discharge gradients. Mean annual discharge and temperature did not show a clear trend and did not affect exotic fish species invasion, which progressed with time irrespective of these factors. The total number of species fluctuated without a clear trend, which underlined a progressive substitution of native species with exotic ones. Perhaps surprisingly, the community composition changed over time towards more temperature tolerant but also rheophilic, benthivore and generalist fish species. These results highlight how species interactions could be one of the main factors driving the invasion. Furthermore, our data underlines a continuously rising tide of exotics, which questions the success of past control strategies. Considering the current conservation resources limitations, priority should be given to the development of prevention strategies in order to avoid new species introductions.

scholarly journals Effect of the Human Utilization of Northern Snakehead (Channa argus Cantor, 1842) on the Settlement of Exotic Fish and Cladoceran Community Structure

2021 ◽  
Vol 13 (5) ◽  
pp. 2486
Author(s):  
Jong-Yun Choi ◽  
Seong-Ki Kim
Keyword(s):  
Community Structure ◽  
Fish Species ◽  
Micropterus Salmoides ◽  
Lepomis Macrochirus ◽  
Nakdong River ◽  
Exotic Fish ◽  
Carnivorous Fish ◽  
Channa Argus ◽  
The Nakdong River ◽  
Exotic Fish Species

Empirical studies suggest that changes in the density of top predators, such as carnivorous fish, in freshwater food webs, strongly affect not only fish communities but also various primary and secondary consumers. Based on these findings, we explored how differences in the utilization of carnivorous fish (i.e., Northern Snakehead, Channa argus) by humans affected the fish and cladoceran community structure as well as the settlement of exotic fish species (i.e., Lepomis macrochirus and Micropterus salmoides) in 30 wetlands located in the upper and lower reaches of the Nakdong River. Our results show that in the mid–lower reaches of the Nakdong River, the density of C. argus was low, while high densities of L. macrochirus and M. salmoides were observed. Exotic fish species are frequently consumed by C. argus, leading to a low density of L. macrochirus and M. salmoides in the upper reaches, which supported a high density of C. argus. However, in the mid–lower reaches, the density of L. macrochirus was high because of the frequent collection of C. argus by fishing activities. The dominance of L. macrochirus significantly changed the structure of cladoceran communities. L. macrochirus mainly feeds on pelagic species, increasing the density of epiphytic species in the mid–lower reaches. The continued utilization of C. argus by humans induced a stable settlement of exotic fish species and strongly affected the community structures of primary consumers in the 30 wetlands. The frequency of C. argus collection has to be reduced to secure biodiversity in the mid–lower reaches of the Nakdong River, which will reduce the proportion of exotic fish species and increase the conservation of native fish.

scholarly journals Ecofeminism and Natural Resource Management: Justice Delayed, Justice Denied

2021 ◽  
Vol 13 (13) ◽  
pp. 7319
Author(s):  
Yang Liu ◽  
Muhammad Khalid Anser ◽  
Khalid Zaman
Keyword(s):  
Mineral Resource ◽  
Natural Resource ◽  
Access To Finance ◽  
Positive Role ◽  
Women’S Autonomy ◽  
Ecological Footprints ◽  
Women's Autonomy ◽  
Resource Rents

Women have a right to excel in all spheres of activity. However, their roles are mainly confined in the resource extraction industry due to masculinity bias. African women are considered exemplary cases where women have low access to finance and economic opportunities to progress in the natural resource industry. This study examines the role of women’s autonomy in mineral resource extraction by controlling ecological footprints, financial development, environmental degradation, economic growth, and changes in the general price level in the Democratic Republic of the Congo data from 1975–2019. The autoregressive distributed lag estimates show that in the short-run, women’s autonomy decreases mineral resource rents; however, this result disappears in the long-run and the positive role of women’s autonomy in increasing resource capital is confirmed. Ecological footprints are in jeopardy from saving mineral resources both in the short- and long-term. Financial development negatively impacts mineral resource rents, while women’s access to finance supports the mineral resource agenda. The positive role of women in environmental protection has led to increased mineral resource rents in the short- and long-term. Women’s social and economic autonomy increases mineral resource rents in the short-term, while it has evaporated in the long-term. The Granger causality has confirmed the unidirectional linkages running from women’s green ecological footprints, access to finance, and women participating in environmental protection to mineral resource rents in a country. The variance decomposition analysis has shown that women’s economic autonomy and access to finance will exert more significant variance shocks to mineral resource rents over the next ten years’ period. The results conclude the positive role of women’s freedom in the mineral resource sustainability agenda. Thus, there is a high need to authorize women through access to finance and economic decisions to restore natural resource capital nationwide.

scholarly journals The Long-term Effects of Instruction on EFL Learners' Use of Complaining Formulas

10.29007/5xsb ◽  
2018 ◽  
Author(s):  
Alicia Martínez-Flor ◽  
Esther Usó-Juan
Keyword(s):  
Foreign Language ◽  
Language Learners ◽  
Future Research ◽  
Long Term Effects ◽  
Positive Role ◽  
Efl Learners ◽  
Foreign Language Learners ◽  
Over Time

Studies analysing the positive role of pragmatic instruction in formal settings have increased over the last decades. Within this area of interventional pragmatics, some studies have particularly examined whether the effectiveness of the instruction implemented is sustained over time. In order to shed more light on the long-term effects of instruction, this research investigates English as a Foreign Language learners’ use of complaining formulas not only after immediately receiving instruction, but also two months later. Results show that learners keep using a variety of appropriate complaining formulas two months after having participated in the instructional period. These findings are discussed and directions for future research suggested.

Long Term Follow-up of a Population of Low-Intermediate Risk Myelodisplastyc Syndrome Patients Treated with a Combination of Recombinant Erythropoietin, 13-Cis-Retinoic Acid and Dihydroxylated Vitamin D3 Confirms the Positive Role of Erythroid Response on Survival

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4968-4968
Author(s):  
Dario Ferrero ◽  
Elena Crisà ◽  
Antonella Darbesio ◽  
Cristina Foli ◽  
Valentina Giai ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Median Survival ◽  
Vitamin D3 ◽  
Recombinant Erythropoietin ◽  
Positive Role ◽  
Erythroid Response ◽  
Long Term Follow Up

Abstract Abstract 4968 In our previous paper (Ferrero et al, BJH 2009) we reported the treatment of 63 MDS patients (median age 75, 16 RAEB1, 47 non RAEB) with a combination of human recombinant erythropoietin (alfa or beta epoetin, 30–80000 U/ week, median 65000U/week), 13-cis-retinoic acid (20 mg day) and dihydroxylated vitamin D3 (1 ug day). Eleven of the 16 RAEB1 patients also received intermittent, low dose of 6-thioguanine. In spite of adverse prognostic factors for response to erythropoietin (all patients with Hb <9.5 g/dl, 70% transfusion dependent, 51% IPSS intermediate 1 or 2) 64% of non RAEB and 50% of RAEB1 displayed an erythroid response according to Cheson et al (Blood 2006). At previous evaluation (41 months of follow-up) a survival advantage was evident for non RAEB patients with erythroid response. Now we updated the casistic after 3 years from the previous evaluation. Median follow up for alive patients is now 64 months (5 months - 12 years). Median duration of erythroid response is now increased to 25 (2-88+) months for non RAEB and 6 (2.5-34.5+) months for RAEB1, 32.5% of responses in non RAEB patients have lasted more than 3 years. Twenty-nine/46 non RAEB and 14/16 RAEB1 patients died, with a median survival respectively of 57 and 15 months. Acute myeloid leukemia evolution occurred to 10 patients (5 RAEB1 and 5 non RAEB patients). Although the erythroid response did not correlate with known risk factors such as IPSS score, caryotype and transfusion requirement, it confirmed its positive prognostic role for survival in non RAEB patients (p 0.04, HR 2.06): median survival 71.5 months (range 12–150+) for responders, 30.6 months (range 5–149) for non responders. A trend towards a better survival for responder was also observed among RAEB1 patients (median survival 17 months for responders, 10 months for non responders), however, due to the low numbers of patients in this group, the difference was not statistically significant, even if border line (p 0.052, HR 2.52). In conclusion our long term follow-up confirmed the positive role of our combined treatment for response duration and survival in a group of non RAEB patients, most of them with unfavorable prognostic features.Figure 1.Overall survival of myelodisplastyc patients according to erythroid response: A. Non-RAEB patients:“___” responsive patients, “—” not responsive patients (p 0.04, HR 2.06) B. RAEB patients: “___” responsive patients, “—” not responsive patients (p 0.05, HR 2.52)Figure 1. Overall survival of myelodisplastyc patients according to erythroid response: A. Non-RAEB patients:“___” responsive patients, “—” not responsive patients (p 0.04, HR 2.06) B. RAEB patients: “___” responsive patients, “—” not responsive patients (p 0.05, HR 2.52) Disclosures: Off Label Use: The use of 13-cis retinoic acid and 1; 25(OH)2 vitamin D3 in myelodisplastyc syndrome is off-label. In our study we used that drugs in combination with erythropoietin as differentiative agents.

scholarly journals Limnological changes in Dom Helvécio Lake (South-East Brazil): natural and anthropogenic causes

2010 ◽  
Vol 70 (3 suppl) ◽  
pp. 795-802 ◽  
Author(s):  
PM. Maia-Barbosa ◽  
LG. Barbosa ◽  
SL. Brito ◽  
F. Garcia ◽  
CFA Barros ◽  
...  
Keyword(s):  
Species Composition ◽  
Fish Species ◽  
Environmental Data ◽  
Exotic Fish ◽  
Biological Features ◽  
Physical Chemical ◽  
Exotic Fish Species ◽  
Plankton Species

In order to verify changes in physical, chemical and biological features of Dom Helvécio Lake (South-East Brazil), this study compares previous and recent data obtained from limnological investigations over three decades. Plankton species composition and density together with environmental data from 1978, 1983, and during 1999 to 2006 showed changes driven by seasonal climatic forces or by anthropogenic causes. Changes in diversity are shown as a consequence of alternation of rainy and dry periods and introduction of exotic fish species. Finally, suggestions are made for improving conservation efforts in the area, through planned actions and monitoring programmes.

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