A habitat-use model to determine essential fish habitat for juvenile brown shrimp (Farfantepenaeus aztecus) in Galveston Bay, Texas

A density prediction model for juvenile brown shrimp (Farfantepenaeus aztecus) was developed by using three bottom types, five salinity zones, and four seasons to quantify patterns of habitat use in Galveston Bay, Texas. Sixteen years of quantitative density data were used. Bottom types were vegetated marsh edge, submerged aquatic vegetation, and shallow nonvegetated bottom. Multiple regression was used to develop density estimates, and the resultant formula was then coupled with a geographical information system (GIS) to provide a spatial mosaic (map) of predicted habitat use. Results indicated that juvenile brown shrimp (<100 mm) selected vegetated habitats in salinities of 15−25 ppt and that seagrasses were selected over marsh edge where they co-occurred. Our results provide a spatially resolved estimate of high-density areas that will help designate essential fish habitat (EFH) in Galveston Bay. In addition, using this modeling technique, we were able to provide an estimate of the overall population of juvenile brown shrimp (<100 mm) in shallow water habitats within the bay of approximately 1.3 billion. Furthermore, the geographic range of the model was assessed by plotting observed (actual) versus expected (model) brown shrimp densities in three other Texas bays. Similar habitat-use patterns were observed in all three bays—each having a coefficient of determination >0.50. These results indicate that this model may have a broader geographic application and is a plausible approach in refining current EFH designations for all Gulf of Mexico estuaries with similar geomorphological and hydrological characteristics.

Scales of spatial variation in demography of a large coral-reef fish: an exception to the typical model?

Spatial variation in demographic parameters of the red throat emperor (Lethrinus miniatus) was examined among 12 coral reefs in three geographic regions (Townsville, Mackay, and Storm Cay) spanning over 3° of latitude of the Great Barrier Reef, Australia. Estimates of demographic parameters were based on age estimates from counts of annuli in whole otoliths because there was no significant difference in age estimates between whole and sectioned otoliths. There were significant regional differences in age structures, rates of somatic and otolith growth, and total mortality. The Townsville region was characterized by the greatest proportion of older fish, the smallest maximum size, and the lowest rates of otolith growth and total mortality. In contrast the Mackay region was characterized by the highest proportion of younger fish, the largest maximum size, and the highest rates of otolith growth and total mortality. Demographic parameters for the Storm Cay region were intermediate between the other two regions. Historic differences in fishing pressure and regional differences in productivity are two alternative hypotheses given to explain the regional patterns in demographic parameters. All demographic parameters were similar among the four reefs within each region. Thus, subpopulations with relatively homogeneous demographic parameters occurred on scales of reef clusters. Previous studies, by contrast, have found substantial between-reef variation in demographic parameters within regions. Thus spatial variation in demographic parameters for L. miniatus may differ from what is assumed typical for a coral-reef fish metapopulation.

Analysis of four decades of high elevation climate data

Four decades of instrumented climate records at D1 on Niwot Ridge suggest that high elevation data are an important - and even unique - part of the full climate picture. High elevation data provide information on changing lapse rates as well as model verification for global warming, which is predicted to occur earliest in high latitudes and at high elevations. The D1 records show climatic trends that arguably support global warming, assuming that greater planetary wave amplitude is verification of warming. Lapse rates reflect conditions of air mass stability, atmospheric moisture, and could [sic] cover, which contribute to feedback processes involving temperature, precipitation, and snowpack. The D1 record show a period, 1981-1985, when the lapse rate increased significantly, and this change was not detected by other data.

Estimates of growth, mortality, recruitment pattern and MSY of important resources from the Maharashtra coast

Based on the data collected from the year 1987-1991 the growth, mortality and recruitment pattern of eighteen species of fish, two species of cephalopods and four species of penaeid prawns have been presented in the present communication. The total mortality coefficient, (Z) varied from lowest of 1.20 for O. cuvieri to a highest of 10.78 for P. stylifera. The natural mortality coefficient, (M) varied from 0.52 for T. thalassinus to 3.44 for S. crassicornis. The average annual yield of eighteen species of fish, four species of prawns and two species of cephalopods are 65.083, 38.404 and 11.373 tons as against the MSY of 83.023, 72.460 and 10.475 tons respectively. The MSY estimated for the total fish stock is 1.77.753 tons whereas the present yield is 1.14.859 tons. This indicates that higher yield can be obtained by increasing the effort.

National Agricultural Research Organisation. Fisheries Resources Research Institute Annual Report 1999/2000

Lake Victoria shoreline in Jinja Municipality has four urban wetlands of Kirinya West/Loco, Kirinya East/Walukuba, Masese and Budumbuli which have undergone major changes during the past fifty years due to increased human activities. Amongst these activities is the continuous inflow of agricultural run-off, industrial and municipal wastewater. A significant increase in nutrient loads of Nitrogen and Phosphorus from the catchment area continues to enhance eutrophication of Lake Victoria. Pollution from point sources (Industrial plants and NWSC Kirinya final maturation pond) into Jinja’s urban wetlands were therefore studied using a simplified material flux analysis methodology to identify the active elements and estimate the pollution loads due to Nitrogen, Phosphorus, Carbon (nutrients), Chromium, Copper, Lead, Nickel and Manganese metals.

Poverty in the fisheries, inductors, causes and intervention

The study is prompted by the poverty that persisted among the fishing communities of lake victoria at time of considerable cash inflow into the fisheries development of fish processing industry. There has been need for understanding of the poverty and what strategies would be most appreciate for it's reduction.This study has attempted to respond to the needby identifying the nature and distribution of the poverty within the fisheries lake victoria,Uganda, the factor responsible for itand the options for poverty reduction intervention. The study examined the global and regional perspectives of poverty and wealth distribution, noting that wide disparities existed between the developed and the developing world and also between the developing countries themselves. A historical review of development policies and strategies revealed that while successive strategies were able to contribute to growth, their achievement towards poverty alleviation were less than satisfactory, hence the need for continually developing new strategies. A background to Uganda’s society and economy is provided, examining the demographic, political, environmental and economic conditions of the country. Uganda’s development strategies are reviewed, highlighting the role of the Poverty Eradication Action Plan, Uganda’s main strategy for implementing the policy of poverty reduction and wealth distribution. At the agricultural sector level, the Plan for the Modernisation of Agriculture has been formulated, followed by the National Fisheries Policy, aimed at providing a policy framework for the management and development of the fisheries. An appropriate definition of poverty was formulated, considered relevant to the situation of Lake Victoria. The dimensions of poverty included inadequate basic necessities, low education and health achievements, a sense of insecurity and exposure to risk. The research methodology was enhanced by the examination of the Lélé Model of the Poverty–Environmental Degradation problem, the World Bank Model of Poverty Causation and the subsequent Lake Victoria Model developed in this study. It has provided a plan for the research, the consideration of criteria and a data collection plan. The data collection instruments included secondary data search, key informant interviews and a sample survey based on a structured questionnaire. The study identified all the four dimensions of poverty in the fisheries, provided poverty profiles with respect to the different activities, groups of people and regions in the fisheries, based on consumption poverty. Among the people identified to be in poverty were the fishing labourers, fishers of Oreochromis niloticus and those operating with non-powered boats. In the post-harvest fisheries, large proportions of processors involved in salting and sun-drying, market stall and bicycle traders were in the poverty category. The ethnic groups most affected included the Samia, Basoga and Bakenye while the Districts of Jinja, Bugiri and Busia had the highest proportions of fishers in the poverty category. With respect to the other dimensions of poverty, the study showed that educational achievement was low within the fishing communities. The health status was poor, due mainly to the prevalence of malaria, diarrhoea, bilharzia and HIV/AIDS. There was a sense of insecurity within certain sections of the fishing community, due to leadership weaknesses within the local as well as the Government institutions. Some community members operated in a state of risk because they were vulnerable to episodes of income, health and education. The causes of poverty in fisheries included weaknesses within the institutional and social environment, limitations in the technology available to the poor, resource degradation and unfavourable economic factors. The recommendations of the study for poverty reduction included strengthening of policies, developing links, improving capacities and increasing resources, to be applied at the levels of Central Government, Local Government and of the community. In view of the achievements of the methodology used on this study, involving reference to the models, it is recommended that future research should build upon this model approach, as it will continue to produce results, especially when attempting to forecast changes relating to interventions.

The fisheries resources of Lake Nakivali

Lake Nakivali is one of the four small lakes that form what is known as the koki lake sysyem. It is 14km long,6km wide.26km sqaured in area and has maximum depth of 3.5m at high water level. The lake is located in lake-swamp complex with river Rwizi as the principle inflow, and a number of peripheral lakes among which are four major ones,i.e Lake Nakivali, Mburo, Kachira and Kijanebalola. Lake Nakivali is a controlled lake with four official landing sites, namely: Kikusi, Kahirimbi, Kashojwa and Rukinga. The latter three are located within a Refugee settlement whereas Kikusi is outside. The Nakivali Refugee settlement initially established for Rwandese of Tutsi origin in 1963, now has at least seven nationalities which include people from Rwanda, Democratic Republic of Congo, Somalia, Sudan, Ethiopia, Kenya and Eritrea. By the end of 2006, the lake’s hinterland of about 378 km squared contained 43,448 people of whom 22,448 were refugees. This large population has had stressful impacts on both land and lake resources to the extent that now there is an apparent overfishing on the lake.

Stock assessment of the demersal offshore fishery resources off the Karnataka coast

The total biomass of the demersal stocks in the depth range of 30-200m between 12°401 and 15°N latitudes in the Indian Exclusive Economic Zone is estimated to be a:round 1,23,000 metric tons (t). There is scope for doubling the present catch of about 40,000 t from demersal resources by extending exploitation to 50-200m depth zone. About 78% of this increase is expected to come from four species, namely, Nemipterus japonicus, Priacanthus macracanthus, Saurida tumbil and Arius spp.

Feeding habits and trophic levels of some demersal fish species in the Persian Gulf (Bushehr Province) using Ecopath model

A trophic study was carried out in February of 2012 to January 2013 on the ecosystem in the Persian Gulf, Bushehr provience. A total of 2,948 samples of stomach contents were analyzed based on the weight and number of food items and were identified about 40 preys. Crustacean and bony fish were as a main prey in most of the stomach contents . The mean average trophic level was estimated at 3.6 by Ecopath software. In this research, the mean level were studied between eight species varied from 3.47 to 4.61, Saurida tumbil occupy the highest and the Argyrops spinifer was the lowest level. The ranges of total mortality varied from 0.7 to 3.05 per years. The food consumption rate was estimated about 69.82 per year. The overlap index showed that the prey items such as fish, crustacean, bivalve and echinoderm were shared about 65, 15, 15 and 6 percent in all stomach of individual in respectively. Mixed trophic analysis indicates that benthos have a positive effect on most of the fish species. Most species have a negative impact on themselves, interpreted here as reflecting increased with in group competition for resources. This preliminary model can be helpful to determine the gaps in the present knowledge about demersal system of the Persian Gulf.

Capturing views of men, women and youth on agricultural biodiversity resources consumed in Barotseland, Zambia

This paper presents data and findings from focus group discussions in study communities selected by the CGIAR Research Program on Aquatic Agricultural Systems (AAS) in the Western Province of Zambia. The discussions focused on cultivated crops and vegetables collected from open fields and consumed as food. Participatory tools for agricultural biodiversity (agrobiodiversity) assessment were used to capture community perspectives on plant species and varietal diversity; factors influencing the availability and use of plants for food; unique, common and rare crop species cultivated in a community, identified through a four-cell analysis methodology; and core problems, root causes, effects and necessary actions to tackle them, using problem tree or situation analysis methods.

Physical, chemical, algal composition and primary production in the four Kisoro minor lakes

The study was conducted between 1998 and 1999. Physical, chemical and biological factors of the water quality characteristics were collected and analysed

Development of teaching resources for physical modelling community

Physical modelling of interesting geotechnical problems has helped clarify behaviours and failure mechanisms of many civil engineering systems. Interesting visual information from physical modelling can also be used in teaching to foster interest in geotechnical engineering and recruit young researchers to our field. With this intention, the Teaching Committee of TC2 developed a web-based teaching resources centre. In this paper, the development and organisation of the resource centre using Wordpress. Wordpress is an open-source content management system which allows user content to be edited and site administration to be controlled remotely via a built-in interface. Example data from a centrifuge test on shallow foundations which could be used for undergraduate or graduate level courses is presented and its use illustrated. A discussion on the development of wiki-style addition to the resource centre for commonly used physical model terms is also presented. © 2010 Taylor & Francis Group, London.

Three-Dimensional Tracking of Construction Resources using an On-Site Camera System

Vision trackers have been proposed as a promising alternative for tracking at large-scale, congested construction sites. They provide the location of a large number of entities in a camera view across frames. However, vision trackers provide only two-dimensional (2D) pixel coordinates, which are not adequate for construction applications. This paper proposes and validates a method that overcomes this limitation by employing stereo cameras and converting 2D pixel coordinates to three-dimensional (3D) metric coordinates. The proposed method consists of four steps: camera calibration, camera pose estimation, 2D tracking, and triangulation. Given that the method employs fixed, calibrated stereo cameras with a long baseline, appropriate algorithms are selected for each step. Once the first two steps reveal camera system parameters, the third step determines 2D pixel coordinates of entities in subsequent frames. The 2D coordinates are triangulated on the basis of the camera system parameters to obtain 3D coordinates. The methodology presented in this paper has been implemented and tested with data collected from a construction site. The results demonstrate the suitability of this method for on-site tracking purposes.

An information oriented framework for relating IS/IT resources and business value

Several studies have highlighted the importance of information and information quality in organisations and thus information is regarded as key determinant for the success and organisational performance. At the same time, there are numerous studies, frameworks and case studies examining the impact of information technology and systems to business value. Recently, several studies have proposed maturity models for information management capabilities in the literature, which claim that a higher maturity results in a higher organizational performance. Although these studies provide valuable information about the underlying relations, most are limited in specifying the relationship in more detail. Furthermore, most prominent approaches do not or at least not explicitly consider information as important influencing factor for organisational performance. In this paper, we aim to review selected contributions and introduce a model that shows how IS/IT resources and capabilties could be interlinked with IS/IT utilization, organizational performance and business value. Complementing other models and frameworks, we explicitly consider information from a management maturity, quality and risk perspective. Moreover, the paper discusses how each part of the model can be assessed in order to validate the model in future studies.

Achieving robust face recognition from video by combining a weak photometric model and a learnt generic face invariant

In spite of over two decades of intense research, illumination and pose invariance remain prohibitively challenging aspects of face recognition for most practical applications. The objective of this work is to recognize faces using video sequences both for training and recognition input, in a realistic, unconstrained setup in which lighting, pose and user motion pattern have a wide variability and face images are of low resolution. The central contribution is an illumination invariant, which we show to be suitable for recognition from video of loosely constrained head motion. In particular there are three contributions: (i) we show how a photometric model of image formation can be combined with a statistical model of generic face appearance variation to exploit the proposed invariant and generalize in the presence of extreme illumination changes; (ii) we introduce a video sequence re-illumination algorithm to achieve fine alignment of two video sequences; and (iii) we use the smoothness of geodesically local appearance manifold structure and a robust same-identity likelihood to achieve robustness to unseen head poses. We describe a fully automatic recognition system based on the proposed method and an extensive evaluation on 323 individuals and 1474 video sequences with extreme illumination, pose and head motion variation. Our system consistently achieved a nearly perfect recognition rate (over 99.7% on all four databases). © 2012 Elsevier Ltd All rights reserved.