A historical review of the shad fisheries of North America

A review of the relative productivity and value of the shad fisheries of North America as reflected in recorded commercial catches. A review of reasons for the decline that are biological and socioeconomic. Factors that have been held responsible are: pollution; destruction or impairment of spawning and nursery areas; overfishing; hydroelectric and canal dams; natural fluctuations in abundance. Natural catastrophes, parasites, and predators are not considered important in causing the decrease in commercial production. Attempts to rehabilitate the fisheries by various means of stocking artificially-reared fry and pond-reared fingerling shad, appear to have failed in every instance. Introduction of shad fry on the Pacific Coast has resulted in a major fishery. The most significant program is a controlled catch management plan, operating at this time [1953] only in Maryland.

Discriminação e preconceito no universo balé clássico

Nessa dissertação, procuro compreender como são construídas algumas formas de discriminação racial no mundo do balé clássico. Ou seja, como ser negro ou ser branco é um diferencial nesse contexto, e como esta discriminação é subjetivamente experimentada pelos bailarinos negros. O estudo qualitativo realizado teve por base as entrevistas realizadas com bailarinos daquele universo, que me ajudaram a compor o quadro das relações vivenciadas, revelando reciprocidades e disputas. O ponto de partida desse estudo foi a minha própria trajetória neste universo e a análise das biografias de Eros Volúsia, dançarina brasileira que se projetou internacionalmente, através de coreografias próprias, inspiradas na cultura brasileira e de Mercedes Baptista, a primeira bailarina negra a pertencer ao corpo de baile do Theatro Municipal do Rio de Janeiro. Meu foco principal foram as relações sociais construídas no contexto do balé clássico, bem como as estruturas de poder. Apostei na ideia de que estas se constituíam em um bom caso para se pensar como determinadas modalidades de relações raciais se apresentam no Brasil.

The phytoplankton species composition and abundance of Ogun River, Abeokuta, southwestern Nigeria

The phytoplankton species composition and abundance in Ogun River, Ogun state, Southwest Nigeria was studied for a period of seven months (December, 2011 - June, 2012), a total of forty-one genera belonging to five taxonomic groups were recorded from Ogun River. The phytoplankton species composition was surpassed by Chrysophyta with 15 species consisting of 36.6% followed by Chlorophyta with 14 consisting of 34.1%. This was followed by Cyanophyta (7 species) consisting of 17.1%, Euglenophyta with 3 species consisting of 7.3% and Pyrrophyta with 2 species consisting 4.92%. Cyanophyta was the highest in abundance consisting of 41% while the lowest in abundance was Pyrrophyta consisting of 1.5%. The low nature of phytoplankton abundance and diversity observed in this study must have been caused by the polluted nature of the water due to the anthropogenic activities carried out around its shores The dominance of Cyanophyta in this river is similar to findings from Lake Victoria, Lake Bishoftu, Lake Chaohu and the temple pond of Thirupour.

Farmer-scientist research partnerships for integrated agriculture-aquaculture

A realistic alternative to traditional technology development and transfer has been utilized by the International Center for Living Aquatic Resources Management (ICLARM) to integrate pond fish culture into low-input farming systems in Malawi. Resource mapping was used to assess farm resources and constraints and introduce the concept of integrated resource management (IRM), the synergistic movement of resources between and among farm and household enterprises. Farmer-led IRM research projects are conducted on-farm and monitored by researchers through direct observation and on-station simulation of constraints and management practices. Technology-adoption rates by farmers involved in a pilot activity was 65% compared to 0% by farmers exposed only to top-down extension approaches. Within two years of adoption, every participating farmer had transferred the technology to an average of four other farmers without the involvement of the extension services.

Production and conservation of nutrient-rich small fish (SIS) in ponds and wetlands for nutrition security and livelihoods in South Asia: Proceedings of a World Bank/SAFANSI funded regional workshop on small fish and nutrition, Dhaka, Bangladesh, 1st - 2nd March 2014

Small indigenous fish species (SIS) are an important source of essential macro- and micronutrients that can play an important role in the elimination of malnutrition and micronutrient deficiencies in the populations of many South and Southeast Asian countries. Of the 260 freshwater fish species in Bangladesh, more than 140 are classified as SIS and are an integral part of the rural Bangladeshi diet. As many SIS are eaten whole, with organs and bones, they contain high amounts of vitamins and minerals, including calcium, and iron and zinc. Some SIS, such as mola, are also rich in vitamin A. SIS are often cooked with vegetables and a little oil, so they contribute to the food diversity of the rural poor.SIS are recognized as a major animal-source food group, contributing to improved food and nutrition security and livelihoods of the people of South and Southeast Asia. The purpose of this workshop is to bring together policy makers, extension agents, researchers, non-governmental and development organizations to share knowledge about small fish, their contribution to better nutrition, production technologies, and strategies for wider dissemination of pond culture and wetland based-production and conservation technologies. The workshop is expected to generate ideas for further research and development of sustainable technologies for production, management and conservation of SIS for the benefit of the people of Bangladesh as well as the South and Southeast Asian region.

Preliminary observations on the nursery management of post larvae of Penaeus monodon

Post larvae of tiger prawn (Penaeus monodon) of the size 10-12 mm were stocked at the rate of 10 lakhs/ha in a manured cement nursary pond which was initially fertilized with chemical manures. Water exchange was attended once in a week. Artificial feeding was given in the form of minced clam meat. After a month, the pond was harvested. The juveniles which have grown to 40-46 mm size were recovered. The percentage of survival from post larvae to juveniles was 85.45%.

National issues raised by IIMA study on development and management of freshwater aquaculture in India: a review

An examination is made of various issues regarding freshwater aquaculture development raised by the IIMA study on inland fish marketing in India. The following topics are discussed: 1)fish production and the resources; 2)desirability for refined methodology for assessment of fish production; 3)pond resource under fish culture; 4)conflicting data and 5)observation on research input for freshwater.

Ascorbic acid turnover in the ocular tissues of some fishes

The ascorbic acid turnover from the ocular tissues of 11 species of fishes from a culture pond and the river Godavari (Andhra Pradesh, India) has been studied. The free ascorbic acid and ascorbigen contents were more in the case of bottom or deep dwelling fishes and the least in the case of surface living forms, depending upon the light penetration in the area that each species inhabits. The enzymic utilization and ascorbic acid-macromolecule complex varied among the fishes possibly depending upon individual energy requirements and not upon light intensity. No size-related or sex-related variation was observed. No variation was observed between riverine and pond-reared fishes of the same species.

On acid sulfate soils of the coastal aquaculture ponds of Bangladesh

With the stimulus of the very high international market value of penaeid shrimp, new pond areas for shrimp farming are rapidly being added in Bangladesh. Unfortunately, this expansion is occurring with the loss of some natural mangrove forests and with soils and sediments that are far from ideal for aquaculture. In this study, two representative shrimp farming areas were surveyed and pH, in profile depth, was recorded. It was found that the shrimp farming areas of the Chakaria Sundarban are more acidic than those of the Khulna-Satkhira region due to the acid sulfate soils.

Nursery rearing of Macrobrachium rosenbergii (de Man) using hapa-nets: effects of stocking density

An experiment was conducted in two phases for 45 days each to study the effects of six stocking densities (phase-I: 100, 200 and 300 PL/m² and phase-II: 250, 500 and 750 PL/m²) on growth and survival of Macrobrachium rosenbergii postlarvae (PL) in nylon hapa-nets (1.8m x 1.8m x 1.4m) installed in a pond. Stocking densities of 100, 200 and 300 PL 10/m² resulted in similar (P<0.05) body length (47-48 mm) and survival rate (84-88%), while body weight (0.62g) in PL with 300/m² was significantly lower than that (0.70g) in PL with 100 and 200/m². The growth (body length 47mm and weight 0.64g) and survival (84%) of PL stocked at 250 PL/m² density were significantly higher (P<0.05) than that of PL at 500 and 750/m². Besides the variation in growth and survival in PL at six tests stocking densities, a sharp increase in body weight of PL was observed beginning at the 4th week of rearing.

Impact of stocking density on growth and survival rate of mud crab (Scylla serrata Froskal)

A 10-weeks culture trial of mud crab, Scylla serrata in brackish water earthen pond was conducted in different stocking densities. The aim of the experiment was to identify a suitable stocking density for optimum production. There were three treatment as 5000 crab lings/ha, 10000 crab lings/ha and 15000 crab lings/ha of each with three replications. The initial mean weight of crab lings were same (5.5 ± 0.13 g). The experimental month was June '95 to August '95. The size of each pond was 500 m². To maintain good water quality water was exchanged in every spring tide. The salinity during the experiment were 2-18ppt. Prepared feed of about 32% protein consisting fish meal, MOC rice bran and wheat flour was used at 5% of their body weight. In terms of production, survival rate, growth and carapace width, the stocking density having 10000/ha showed the best (P

Effect of stocking density on growth of tiger shrimp (Penaeus monodon Fab.) fed on commercial formulated diets

Three different stocking rates in a semi-intensive pilot shrimp project was adopted in duplicates of three treatments designated as T1, T2 and T3 having initial per meter square stocking density of shrimp of 40, 44 and 51 respectively of 0.025g size post larva. The study was conducted for 84 days. Commercial pelleted diets designated as starter - 1, 2, 3 and grower were fed at a satiation level during the study period with a feeding frequency of 4 to 5 times per day. Feed rationing was based on the survivability, body weight and tray checking. 5-25% of the pond water was exchanged daily. Sampling was done for growth after every 2nd week. Monthly sampling was done for mortality in the ponds. Mean weight gain of the shrimp in treatments T1, T2 and T3 were 16.96 ± 1.14, 16.04 ± 1.38 and 14.08 ± 1.17g respectively and T1 with a low stocking density showed a significantly best growth among the treatments. Total mortality in treatments T1, T2 and T3 were as 30.00, 39.77 and 31.37% respectively. Significantly higher feed conversion ratio (FCR) of 1.87 was obtained with shrimp in treatment T3 followed by shrimp in T1 and T2 with FCR values of 1.70 and 1.41 respectively. A positive correlation of growth and salinity was observed during the study. Total production per unit area was the highest in the treatment T3 (4928 kg/ha) and followed by T1 (4747 kg/ha) and T2 (4251 kg/ha). The result show significantly negative correlation between individual growth and density.

Mixed culture of fishes in seasonal ponds through fertilization and feeding

A study on mixed culture of mirror carp (Cyprinus carpio Lin.), tilapia (Oreochromis niloticus Lin.), silver carp (Hypophthalmicthys molitrix Val.) and Thai sharpunti (Puntius gonionotus Bleeker) in the ratio of 1:2:2:5 was conducted in 12 seasonal mini ponds (30 m² each) for 105 days. There were six treatments each with two replicates and each pond was stocked with a total of 100 fishes. Rice bran and mustard oil cake were used as supplemental feed either in combination or alone in presence or absence of fertilizer. Fertilizers were used in the form of organic, inorganic or both. The best growth performance of mirror carp, tilapia and Thai sharpunti was obtained in treatment III which received both fertilizer (organic+inorganic) and rice bran while the highest growth of silver carp was obtained in treatment VI receiving only inorganic fertilizer. However, the overall best production (2450 Kg/ha) and economic return for the culture period was obtained in treatment VI followed by treatment III. The results are discussed in the light of water quality parameters.

Survival of antibiotic resistant Pseudomonas strains in different types of water

A study was conducted to investigate the survival of five Pseudomonas strains resistant to antibiotics in different types of water. The selected Pseudomonas strains were designated as strain P1 (CT-29), strain P2 (CT-25), strain P3 (CT-36), strain P4 (CT-20) and strain P5 (CT-27) which were only recovered from farmed fishes. Six types of water viz., distilled water, saline water, tap water, deionized water, pond water and river water were used. Among these experimental waters, river water was found to be the most suitable for long-term survival of these strains. Deionized water did not support survival of all these Pseudomonas strains. Pond water, tap water and distilled water were moderately suitable for strain P1 and strain P4. Saline water was also found to be highly suitable for long-term survival in case of the strain P3 and moderately suitable for normal survival of strain P2 and strain P5.

Culture feasibility of african catfish (Clarias gariepinus Lin.) fry in glass tank and synthetic hapa system using supplemental diets

An experiment was carried out with 1 0 days old Clarias gariepinus fry over a period of 42 days to determine the effects of different feeds on growth and survival of African catfish fry in glass tanks. The experiment was designed into four treatments each having three replications. Thus treatment 1 (T1) was named as Tank Tubifex (TT) and treatment 2 (T2) as Tank Sabinco (TS), treatment 3 as Pond Tubifex (PT), and treatment 4 (T4) as Pond Sabinco (PS). Live Tubifex (protein levels 64.48%) was supplied to treatments 1 and 3 and rest of the treatments were supplied Sabinco starter-1 (protein levels 40.13%). The highest and the lowest growth in total length and weight were 12.90cm, 18.77g and 6.17cm, 4.04g recorded from the treatments 3 and 2, respectively. Growth of catfish fry under treatment 3 in terms of both length and weight were significantly higher (P<0.01) than those of the other treatments. However treatment 2 showed the significantly lowest (P<0.01) growth performance among the various treatments. The highest survival rate (92%) was also obtained with treatment 3. Tubifex proved to be the best larval feed in respect of growth and survival rate.