scholarly journals The effect of management choices on the sustainability and economic performance of a mixed fishery: a simulation study

2008 ◽  
Vol 65 (4) ◽  
pp. 697-712 ◽  
Author(s):  
S. B. M. Kraak ◽  
F. C. Buisman ◽  
M. Dickey-Collas ◽  
J. J. Poos ◽  
M. A. Pastoors ◽  
...  

Abstract Kraak, S. B. M., Buisman, F. C., Dickey-Collas, M., Poos, J. J., Pastoors, M. A., Smit, J. G. P., van Oostenbrugge, J. A. E., and Daan, N. 2008. The effect of management choices on the sustainability and economic performance of a mixed fishery: a simulation study. – ICES Journal of Marine Science, 65: 697–712. Alternative management scenarios were evaluated in a simulation framework that mimicked the recent exploitation of sole and plaice in the North Sea. A large proportion of plaice is taken as bycatch of the beam trawl fleet targeting sole, yet current management of the two stocks assumes no interaction in their exploitation. The evaluation criteria included biological and economic sustainability, and stability in the management measures. The fishery was assumed to respond to management restrictions by dropping the least profitable trips. We investigated two contrasting management strategies, single-species total allowable catches, and effort regulation. Under the assumptions made, the latter strategy performed better. The results suggest that, given assessment error and bias, a strategy that accounts for the mixed nature of a fishery and that occasionally results in perceived underexploitation may work best. Stability in fishing mortality reinforces itself, through lower assessment bias, and management corrections become less frequent. The common assumption in many stock assessments in EC waters that fishing mortality in the most recent year should resemble the value obtained in previous years (“shrinkage”) had a negative effect on the stability of control measures.

Author(s):  
W.N. Reynolds

Following the 2007/08 drought, we experienced poor pasture production and persistence on our dairy farm in north Waikato, leading to decreased milksolids production and a greater reliance on bought-in feed. It is estimated that the cost of this to our farming operation was about $1300 per hectare per year in lost operating profit. While climate and black beetle were factors, they did not explain everything, and other factors were also involved. In the last 3 years we have changed our management strategies to better withstand dry summers, the catalyst for which was becoming the DairyNZ Pasture Improvement Focus Farm for the north Waikato. The major changes we made were to reduce stocking rate, actively manage pastures in summer to reduce over-grazing, and pay more attention to detail in our pasture renewal programme. To date the result has been a reduced need for pasture renewal, a lift in whole farm performance and increased profitability. Keywords: Focus farm, over-grazing, pasture management, pasture persistence, profitability


2019 ◽  
Vol 10 (11) ◽  
pp. 1089-1097
Author(s):  
Nguyen Quynh Hoa ◽  
◽  
Phung Chu Hoang ◽  

Quality outcomes from vocational education and training (VET) are fundamental to ensuring a skilled workforce and supporting a productive economy. The quality of vocational training from the demand’s perspective is defined as meeting the customer specification, needs or requirements. Using the method of Exploratory Factor Analysis (EFA) and Multiple Regression Analysis to get the analytical results of 275 respondents as graduates of University of Transport and Communication, University of Transport Technology (the two universities training on transportation in the North of Vietnam), the results show that factors are measured by the observed variables in the study that ensure reliability and relevance. The descriptive statistics result of vocational training quality is 3.28, while all independent variables are at average level (between 3.1 to 3.48) with the highest value related to the quality of the teacher and the lowest are facilities and training programs and management capacity of university. However, the regression results show that the qualification of the teacher, material facilities and training program, management capacity and job opportunities at the training school do not affect the quality of the training while “Learners-NH” have a great positive effect and the labor market information has a negative effect on the training quality of the school significantly. Base on those data, some policy recommendations have been given out in order to improve the training quality of transport technology universities in the north of Vietnam in particular and the vocational training quality of Vietnam in general.


2019 ◽  
Vol 3 (V) ◽  
pp. 286-304
Author(s):  
Shadrack Musunkui Towett ◽  
Isaac Naibei ◽  
Williter Rop

In an attempt to bridge the gap between the budgetary allocations and actual expenditures most universities have started income generating units with the aim of boosting their operational expenses. Whereas there is the potential of the use of Income Generating Units (IGUs) to generate additional funds, most universities still experience challenges in full implementation and realization of the revenue goal. This study therefore sought to determine the financial control mechanisms affecting performance of income generating units among selected public universities. The study sought to determine the effect of internal controls, credit policies, financial risk management and internal audit on performance of income generating units in selected universities. Targeted population was all the 290 employees in the IGU departments of selected public universities. The respondents were sampled using simple random sampling so as to enable equal representation of the target population without any biasness. Data collection was done using the questionnaire to ensure sufficient data was collected from the respondents. Descriptive statistics assisted in the determination of respondent’s views and opinions on every variable. Qualitative data was analysed using content analysis into meaningful, precise and comprehensive statements and presented in quotations. Data analysis was done using SPSS version 21 and data presented in form of figures and tables. The study ensured that all ethical considerations were considered by the study. The findings were that most employed Income Generating Units in Public Universities were Collection of rental fees, Evening and executive programs and Trainings of both short and long courses while the least was established to be Sales of memorabilia and books. All the financial control mechanism investigated namely internal audit, internal control measures, risk management strategies and credit policies had large extents of adoption in the selected universities. The results of the regression analysis showed that the financial control mechanisms investigated had a significant positive relationship on performance of the IGUs. Specifically, 47% of the variation of the performance of IGUs was established to be explained by the studied factors. The study concluded that the performance of the IGUs among the selected public universities was largely accounted for by the implemented financial control measures. Therefore effective financial control mechanisms is concluded to lead to better IGU performance whereas shortcomings in the financial control mechanisms is concluded to lead to diminished returns in the IGUs. The study recommended that the management in charge of the IGU department in the public universities to prioritize the formulation, implementation and monitoring of financial control mechanisms in the IGUs. To facilitate effective financial controls, the study recommended that the management especially those in the audit section to conduct regular checks and inspections on the IGUs. Additionally, frequent reforms were recommended to address the shortcomings experienced in integrating financial control measures in IGUs.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 509e-509
Author(s):  
Robert P. Rice

The Cal Poly philosophy of “Learn and Understand by Doing” has been integrated with problem-based learning and the use of the latest technology to produce a class that closely simulates real-life pest control situations. Goals of the class, Disease and Pest Control Systems for Ornamental Plants, are to teach students pest monitoring, control and problem solving techniques, the use of resources including the internet and journals, and the use of the latest pest control equipment and application techniques. Students are shown pest situations and then work in groups to diagnose the problem, investigate management strategies, apply control measures, and monitor results. Weekly class presentations inform the class of the various projects and help to teach the class organization and presentation skills. Student evaluations and test performance have demonstrated that students achieve class objectives substantially better with the problem-based learning approach than with the previous lecture-based approach to the class.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 522
Author(s):  
Akli Benali ◽  
Ana C. L. Sá ◽  
João Pinho ◽  
Paulo M. Fernandes ◽  
José M. C. Pereira

The extreme 2017 fire season in Portugal led to widespread recognition of the need for a paradigm shift in forest and wildfire management. We focused our study on Alvares, a parish in central Portugal located in a fire-prone area, which had 60% of its area burned in 2017. We evaluated how different fuel treatment strategies may reduce wildfire hazard in Alvares through (i) a fuel break network with different extents corresponding to different levels of priority and (ii) random fuel treatments resulting from a potential increase in stand-level management intensity. To assess this, we developed a stochastic wildfire simulation system (FUNC-SIM) that integrates uncertainties in fuel distribution over the landscape. If the landscape remains unchanged, Alvares will have large burn probabilities in the north, northeast and center-east areas of the parish that are very often associated with high fireline intensities. The different fuel treatment scenarios decreased burned area between 12.1–31.2%, resulting from 1–4.6% increases in the annual treatment area and reduced the likelihood of wildfires larger than 5000 ha by 10–40%. On average, simulated burned area decreased 0.22% per each ha treated, and cost-effectiveness decreased with increasing area treated. Overall, both fuel treatment strategies effectively reduced wildfire hazard and should be part of a larger, holistic and integrated plan to reduce the vulnerability of the Alvares parish to wildfires.


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 425
Author(s):  
Rodrigue Vivien Cao Diogo ◽  
Luc Hippolyte Dossa ◽  
Sèyi Fridaïus Ulrich Vanvanhossou ◽  
Badirou Dine Abdoulaye ◽  
Kossi Hélliot Dosseh ◽  
...  

The sustainable use of rangelands in pastoral areas requires the inclusion of all stakeholders to develop sound management strategies. However, the role of these actors in the sustainable management of natural resources is still poorly understood. The present study aims to (i) assess the perception of farmers and herders of the risks and opportunities of transhumance on rangeland resource use and management, and to (ii) generate useful knowledge for the design and implementation of policies that favor the coexistence of these actors and reduce competition over rangeland resources use in Benin. To this end, interviews were conducted with 240 crop farmers and herders using a semi-structured questionnaire in two contrasting agroecological zones in the northern (Kandi) and the southern (Kétou) part of the country. Among the respondents, 64% of farmers in the North were agro-pastoralists (owning 10.6 ha of land and 10.7 cattle) and 36% were herders (keeping 45.8 cattle and cultivating about 3.7 ha of land). They perceived that communal rangelands were entirely degraded. In the South, 36% of respondents were agro-pastoralists (with 0.3 cattle and farming 4 ha of land) and 64% cattle herders (raising 45.3 cattle and farming 0.9 ha of land only). Of the herders, 50% kept cattle for more than 20 years, while agro-pastoralists had no previous experience in cattle herding. Cultivation practices among crop farmers, such as high use of mineral fertilization (23.8%) and bush fires for land clearing (22.5%), were reported in Kandi (North) and Kétou (South) as factors that might contribute to land degradation. However, these farmers perceived transhumance as a threat to the sustainable use of natural resources. In contrast, herders perceived transhumance as an opportunity to valorize unused land and increase the availability of manure to cropland. The prevalent negative attitude of crop farmers regarding transhumant herders increases the vulnerability of cattle herding in both regions. There is an urgent need of raising awareness concerning the mutual benefits provided by the coexistence of crop farmers with herders to promote participative rangeland management strategies. This may contribute towards coping with the current challenges of food insecurity and increasing climate variability as well as to reducing recurrent conflicts in the region.


2014 ◽  
Vol 41 (7) ◽  
pp. 545 ◽  
Author(s):  
Britney Niedzielski ◽  
Jeff Bowman

Context In an era of rapid environmental change, many species are shifting their distributions. As temperate-zone species’ expand their ranges north, different and potentially severe limiting factors may begin to affect their ability to survive and reproduce. The wild turkey (Meleagris gallopavo) is one example of a species undergoing rapid northern expansion. Aims An improved understanding of wild turkey demography at the species’ northern range periphery would facilitate effective management of this important game species. Therefore, we undertook a study to evaluate survival, causes of mortality, and behavioural strategies that may govern survival of female wild turkeys. Methods We captured 53 female wild turkeys, and used backpack transmitters to monitor their individual fates during 2012–13. Key results The annual survival estimate was 0.37 (95% CI: 0.25–0.55), with the lowest seasonal survival in the winter. The most frequent cause of mortality was mammalian predation, predominately by coyotes (Canis latrans). Age, proximity to supplemental food, and habitat use did not affect risk of mortality. Conclusions Northern wild turkeys in our study exhibited lower survival and suffered higher predation than did populations in the species’ historic range. Despite our findings, the wild turkey has expanded its range northwards and continues to exist in these peripheral areas. This may be due to high productivity or a source–sink dynamic, whereby high mortality is offset by immigration from the south. Implications The low survival and high predation of wild turkeys in the north must be considered when developing management strategies, particularly if interest exists in translocating turkeys farther north. Further research is needed to better understand whether northern turkey populations persist as sinks.


2013 ◽  
Vol 21 (2) ◽  
pp. 71-84 ◽  
Author(s):  
Guy R. Larocque ◽  
Nancy Luckai ◽  
Shailendra N. Adhikary ◽  
Arthur Groot ◽  
F. Wayne Bell ◽  
...  

Competition in forest stands has long been of interest to researchers. However, much of the knowledge originates from empirical studies that examined the effects of competition. For instance, many studies were focused on the effects of the presence of herbaceous species on the development of tree seedlings or the decrease in individual tree growth with increases in stand density. Several models that incorporate competitive effects have been developed to predict tree and stand growth, but with simplified representations of competitive interactions. While these studies provided guidance useful for forest management, they contributed only partially to furthering our understanding of competitive mechanisms. Also, most competition studies were conducted in single-species stands. As competitive interactions occurring in mixed stands are characterized by a higher degree of complexity than those in single-species stands, a better understanding of these mechanisms can contribute to developing optimal management scenarios. The dynamics of forest stands with at least two species may be affected not only by competition, but also by facilitation or complementarity mechanisms. Thus, knowledge of the mechanisms may provide insight into the relative importance of intra- versus inter-specific competition and whether competition is symmetric or asymmetric. Special attention to the implementation of field experimental designs is warranted for mixed stands. While traditional spacing trials are appropriate for single-species stands, the examination of competitive interactions in mixed stands requires more complex experimental designs to examine the relative importance of species combinations. Forest productivity models allow resource managers to test different management scenarios, but again most of these models were developed for single-species stands. As competitive interactions are more complex in mixed stands, models developed to predict their dynamics will need to include more mechanistic representations of competition.


2004 ◽  
Vol 61 (8) ◽  
pp. 1398-1409 ◽  
Author(s):  
Morten Vinther ◽  
Stuart A. Reeves ◽  
Kenneth R. Patterson

Abstract Fishery management advice has traditionally been given on a stock-by-stock basis. Recent problems in implementing this advice, particularly for the demersal fisheries of the North Sea, have highlighted the limitations of the approach. In the long term, it would be desirable to give advice that accounts for mixed-fishery effects, but in the short term there is a need for approaches to resolve the conflicting management advice for different species within the same fishery, and to generate catch or effort advice that accounts for the mixed-species nature of the fishery. This paper documents a recent approach used to address these problems. The approach takes the single-species advice for each species in the fishery as a starting point, then attempts to resolve it into consistent catch or effort advice using fleet-disaggregated catch forecasts in combination with explicitly stated management priorities for each stock. Results are presented for the groundfish fisheries of the North Sea, and these show that the development of such approaches will also require development of the ways in which catch data are collected and compiled.


2016 ◽  
Vol 88 (3 suppl) ◽  
pp. 1909-1921 ◽  
Author(s):  
CAMILA I. MEDEIROS ◽  
CAMILA BOTH ◽  
IGOR L. KAEFER ◽  
SONIA Z. CECHIN

ABSTRACT The North American bullfrog Lithobates catesbeianus continues to invade ecosystems worldwide, potentially causing population declines and even extinctions. Within its native distribution, bullfrogs show prolonged reproductive seasons and high fertility. However, data on breeding biology of bullfrogs ex-situ in invaded localities mainly comes from anecdotal reports. Understanding how invasive species are adjusting their life histories to new colonized environments is important for conservation purposes. Here we describe temporal and spatial abundance, calling activity, spawning and tadpole distribution of bullfrogs in southern Brazil. Eighteen samplings occurred during one year. The abundance of individuals was positively related to longer photoperiods and higher temperatures. Reproductive activity was also positively associated with longer photoperiods. Calling sites, spawning and tadpoles were associated with microhabitats presenting hydrophytes, which may provide shelter and thermal stability to bullfrogs. The reproductive seasonal activity of bullfrogs can be highly variable across its growing geographical range, but in subtropical Brazil it is associated with photoperiod, a highly predictable abiotic determinant. In our study area, bullfrogs presented a breeding season twice as long as that observed in some native localities. We suggest that management strategies directed to bullfrog populations must consider the habitat structures and seasonal regimes determined by each invaded environment.


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