Variability in the distribution of planktonic fish eggs and larvae in the nearshore waters off Bombay

Distribution of planktonic fish eggs and larvae in the nearshore waters off Bombay was studied during November 1979 to December 1980. Monthly samples were collected along three transects (Versova, Mahim and Thana) covering eleven stations which represented different environmental conditions. Fish eggs and larvae were common in the area of study with maximum abundance in December 1979 and April/August 1980. Mean density of fish eggs was maximum along the Mahim transect while population of larvae was more in the Versova transect. Total number of families of fish larvae represented in the collections increased from nearshore to offshore area.

Lunar, diurnal and tidal periodicity in relation to the prawn abundance and migration in the Godavari estuarine systems

Preliminary investigations to study the lunar, diurnal and tidal periodicity in abundance and migrations of prawns were made in the Bairavapalam distributary of the Goutami branch of the Godavari estuary during the period of November 1961 to July 1962. The study was based on observation of the catches of a stake net (bag net) operated near the mouth of the estuary. Records of the catches were maintained tidewise daily. Comparative estimates of abundance were made on the basis of catch per hour's operation. It was generally observed that the catches were higher during the darker half of the month than in the brighter fortnight. The landings during low tides were generally higher than those during high tides and usually heavier catches were made during nocturnal low tides than during the day low tides. A continuous inward and outward (immigration and emigration) movement of prawns of all size groups was observed in the estuary from November to July. In general, more penaeid prawns were found to be immigrating at dawn than at dusk. Similarly, the number of emigrants was also found to be generally higher during the new moon period than during the full moon. Metapenaeus monoceros showed an almost distinct nocturnal periodicity in migration, while no such periodicity was observed, distinctly, in other species. In the case of Penaeus indicus the movement of migrants was prolonged. In M. brevicornis the migrants were scarce till March and thereafter increased numerically. The migrant forms of Metapenaeus dobsoni continued to be abundant till May with peak periods in January and February. The migratory pattern of Metapenaeus affinis was similar to that of Metapenaeus brevicornis, though the migrants of the former species appeared a month earlier than the latter. Intensive studies over extended areas for longer periods are required to understand clearly the migratory pattern of the various species. The phenomenon of immigration of prawns can be clearly understood only by vital staining or tagging studies. Perhaps the emigrants might be returning with the succeeding changing life. To verify this, laboratory experiments, by vital stains, were conducted. The marked specimens, if released during the low tides on a large scale, may be recaptured during the subsequent high tides and the duration also may be calculated. At least some percentage of the emigrants remains in the sea for maturity and breeding.

Community water access, availability and management in the Tonle Sap region, Cambodia.

During the rollout of CGIAR Research Program on Aquatic Agricultural Systems (AAS) in Tonle Sap in 2013, water management was highlighted as one of the key development challenges. With limited capacity to regulate water, the situation oscillates between too much water in the wet season and too little water in the dry season. Access to and availability of water were seen by local communities as major limitations for aquatic and agricultural production, impacting on functions that include the lake fishery, intensive (dry season) rice crops, recession rice, rainfed rice and floating rice by the lakeside. For both fish and rice production, water and water management are determined principally by the natural flooding of the Tonle Sap Lake. This study is based on a community survey on water access, availability and management and was conceived out of the AAS consultation process and was developed to help identify existing practices in water use and management, as well as best practices where lessons can be learned and promising activities scaled out to other communities. The community survey also aims to understand, identify and analyze constraints and opportunities related to water, and includes a gender perspective to better understand the role of women in water management and use.

Occurrence of Oriental bonito (Sarda orientalis Temmick and Schlegel) in the inshore waters of Ceylon

The oriental bonito (Sarda Orientalis T. and S.), locally known as thora-baleya, is the least abundant species of the bloodfish group commercially exploited from the inshore waters of Ceylon. The occurrence of this species in Ceylon waters has not been reported and hence it was considered valuable to present, the observations on this species, made in the course of the investigations into the more abundant relatives of this fish, in this preliminary report. In 1964 not more than few hundred pounds of this species was caught from the inshore waters of Ceylon. Since the popularisation of drift-nets for bloodfish fishery in the south, south-west and/west coasts of Ceylon, it is estimated that the annual production has risen to about one ton.

Seasonal variation in the distribution and availability of Carangids ("Paraw" and "Parati") in the Wadge Bank

The Wadge Bank has been exploited regularly by Ceylon based trawlers since 1955 (Sivalingam & Medcof 1957). The bank is about 4,000 sq. miles in extent (Malpas 1926) and is located south of Cape Comorin within the Continental Shelf of India (Fig. 1). Carangids are taken in large numbers during the months of the south west monsoon (Sivalingam 1966). The quantity, in which the Carangids are captured as shown by the fishing records, is large enough to influence the total catch from the bank during these months (Fig. 2). Carangids are held in high esteem as excellent quality food fishes and accordingly constitute a commercially important group. This paper records the results of a detailed examination of the past fishing records in respect of this group, based on the analysis of the catch and fishing effort for the years 1957 to 1962. The distribution pattern of this group of fish in the Wadge Bank is discussed.

Improving design quality and value in the built environment through knowledge of intangibles

Raising design quality and value in the built environment requires continuous improvement, drawing on feedback from clients or occupiers and other industry players. The challenging task for architectural and engineering designers has always been to use their intellectual knowledge to deliver both forms of benefits, tangibles and intangibles, in the built environment. Increasingly as clients demand best value for money, there is a greater need to understand the potential from intangibles, to see projects not as ends in themselves but as means to improved quality of life and wealth creation. As we begin to understand more about how - through the design of the built environment - to deliver these improvements in outcomes, clients will be better placed to expect their successful delivery from designers, and designers themselves will be better placed to provide them. This paper discusses cross-disciplinary issues about intangibles and is aimed at designers, clients, investors and entrepreneurs within the built environment. It presents some findings from a minuscule study that investigated intangible benefits in a new primary school. © 2004 IEEE.

Scale structure, age and growth in the freshwater carp, Labeo calbasu (Pisces/Cyprinidae) from Harike wetland, India

Age structure and growth profile based on the scale studies of 468 specimens ranging from 17-62 cm total length of Labeo calbasu (Hamilton) from Harike wetland (30°13'N, 75°12'E), Punjab, India have been described, the present study showed better growth in terms of two important growth parameters namely index of species average size and population weight-growth intensity. Two distinct phases in its life history have been described that indicates the optimum exploitation of this species from this water body. Harvestable size is found to be fish of 34 cm total length. The detailed structural elaboration of scale (normal, regenerated, lateral line) has also been done using scanning electron microscopy (SEM).

Transient growth and triggering in the horizontal Rijke tube Matthew

This theoretical paper examines a non-normal and non-linear model of a horizontal Rijke tube. Linear and non-linear optimal initial states, which maximize acoustic energy growth over a given time from a given energy, are calculated. It is found that non-linearity and non-normality both contribute to transient growth and that, for this model, linear optimal states are only a good predictor of non-linear optimal states for low initial energies. Two types of non-linear optimal initial state are found. The first has strong energy growth during the first period of the fundamental mode but loses energy thereafter. The second has weaker energy growth during the first period but retains high energy for longer. The second type causes triggering to self-sustained oscillations from lower energy than the first and has higher energy in the fundamental mode. This suggests, for instance, that low frequency noise will be more effective at causing triggering than high frequency noise.

Utilization of treated wood, steel, fibreglass, ferrocement and aluminium in the construction of modern fishing boats and their comparative cost analysis

Modern fishing boats have to be built not only on perfect lines but also with sound and strong construction materials that will ensure a long lasting trouble free service commensurate with the heavy capital investment involved. Choice of construction materials for fishing boats need careful scrutiny as they have to perform too well under most aggressive environments-sea-water and marine atmosphere. A number of alternative boat-building materials are now available whose comparative merits and demerits as well as comparative costs are brought out in this paper.

Extraction, PCR amplification, and sequencing of mitochondrial DNA from scent mark and feces in the giant panda

To expand the feasibility of applying simple, efficient, non-invasive DNA preparation methods using samples that can be obtained from giant pandas living in the wild, we investigated the use of scent markings and fecal samples. Giant panda-specific oligonucleotide primers were used to amplify a portion of the mitochondrial DNA control region as well as a portion of the mitochondrial DNA cytochrome b gene and tRNA(Thr) gene region. A 196 base pair (bp) fragment in the control region and a 449 bp fragment in the cytochrome b gene and tRNA(Thr) gene were successfully amplified. Sequencing of polymerase chain reaction (PCR) products demonstrated that the two fragments are giant panda sequences. Furthermore, under simulated field conditions we found that DNA can be extracted from fecal samples aged as long as 3 months. Our results suggest that the scent mark and fecal samples are simple, efficient, and easily prepared DNA sources. (C) 1998 Wiley-Liss, Inc.