Aquaculture: a rapidly growing and significant source of sustainable food? Status, transitions and potential.

The status and potential of aquaculture is considered as part of a broader food landscape of wild aquatic and terrestrial food sources. The rationale and resource base required for the development of aquaculture are considered in the context of broader societal development, cultural preferences and human needs. Attention is drawn to the uneven development and current importance of aquaculture globally as well as its considerable heterogeneity of form and function compared with established terrestrial livestock production. The recent drivers of growth in demand and production are examined and the persistent linkages between exploitation of wild stocks, full life cycle culture and the various intermediate forms explored. An emergent trend for sourcing aquaculture feeds from alternatives to marine ingredients is described and the implications for the sector with rapidly growing feed needs discussed. The rise of non-conventional and innovative feed ingredients, often shared with terrestrial livestock, are considered, including aquaculture itself becoming a major source of marine ingredients. The implications for the continued expected growth of aquaculture are set in the context of sustainable intensification, with the challenges that conventional intensification and emergent integration within, and between, value chains explored. The review concludes with a consideration of the implications for dependent livelihoods and projections for various futures based on limited resources but growing demand.

Laboratory toxicity test and post-exposure feeding inhibition using the giant freshwater prawn Macrobrachium rosenbergii.

A bioassay was developed using post-larvae of freshwater prawn Macrobrachium rosenbergii (length 9-10 mm) in order to determine the toxicity of profenofos, dimethoate, chlorpyrifos, carbendazim and zinc. This was the first study in the tropics with M. rosenbergii, particularly at the post-larvae stage (9-10 mm) on lethal (LC(50)) and sublethal (EC(50)) effects of toxic substances using post-exposure feeding rate as end point. Median lethal concentrations (LC(50) at 24 and 48 h) were respectively estimated as 11.6 and 9.8 microg L(-1) for profenofos, 142.1 and 102.7 microg L(-1) for dimethoate, 0.7 and 0.3 microg L(-1) for chlorpyrifos, and 439.7 and 329 microg L(-1) for zinc. Effects of carbendazim could not be estimated because carbendazim exposure needs more than 24h exposure period to produce observable effects at the concentrations used. The EC(50) using post-exposure feeding rates determined for profenofos, dimethoate, chlorpyrifos and zinc were 6.023, 269.3, 0.293 and 109.01 microg L(-1), respectively, at 24 h of exposure. Only chlorpyrifos and zinc had LC(50) concentrations greater than the post-exposure feeding EC(50) concentrations. This study demonstrated that the M. rosenbergii could also be used as a test animal to detect the effects of different chemical contaminants in aquatic environments.

Microbial protein production in activated suspension tanks manipulating C:N ratio in feed and the implications for fish culture.

The present experiment investigated the possibility of microbial protein production in 250 l indoor tanks by manipulating C:N ratio in fish feed applied. Two different levels of protein feed (35% and 22% CP) resulting in C:N ratio of 8.4 and 11.6, respectively, were applied at 25 g daily in each tank. Tanks were aerated and agitated continuously using a dome diffuser. The experiment was carried out for eight weeks. The biofloc development in terms of VSS and BOD5 was better in the low protein fed tanks than in the high protein fed tanks. An estimated biofloc productivity ranged 3-5 g Cm(-3)day(-1). A 3-D image stained with DAPI indicates that the biofloc is comprised of hundreds of bacterial nuclei, size being ranged from 100 to 200 microm. Biofloc quality was independent of the quality of feed applied and contained more than 50% crude protein, 2.5% crude lipid, 4% fibre, 7% ash and 22 kJ g(-1) energy on dry matter basis. The dietary composition and size of biofloc can be considered as appropriate for all omnivorous fish species. The underlying ecological processes are explained through factor analysis. The potential of using biofloc in fish culture is also discussed.

Long-term analysis of children with esophageal atresia and tracheoesophageal fistula.

BACKGROUND/PURPOSE: For children with esophageal atresia (EA) or tracheoesophageal fistula (TEF), the first years of life can be associated with many problems. Little is known about the long-term function of children who underwent repair as neonates. This study evaluates outcome and late sequelae of children with EA/TEF. METHODS: Medical records of infants with esophageal anomalies (May 1972 through December 1990) were reviewed. Study parameters included demographics, dysphagia, frequent respiratory infections (> 3/yr), gastroesophageal reflux disease (GERD), frequent choking, leak, stricture, and developmental delays (weight, height < 25%, < 5%, respectively). RESULTS: Over 224 months, 69 infants (37 boys, 32 girls) were identified: type A, 10 infants; type B, 1; type C, 53; type D, 4; type E, 1. Mean follow-up was 125 months. During the first 5 years of follow-up, dysphagia (45%), respiratory infections (29%), and GERD (48%) were common as were growth delays. These problems improved as the children matured. CONCLUSIONS: Children with esophageal anomalies face many difficulties during initial repair and frequently encounter problems years later. Support groups can foster child development and alleviate parent isolationism. Despite growth retardation, esophageal motility disorders, and frequent respiratory infections, children with EA/TEF continue to have a favorable long-term outcome.

Life on the farm-children at risk.

BACKGROUND: More than 1 million children live, play, and work on farms, surrounded by animals and machinery. This symbiotic relationship between work and home exposes children to unique risks. METHODS: Children presenting with a farm-related injury (November 1994 to August 2001, 82 months) were included. Trauma registry parameters included injury severity score (ISS); Glascow Coma Scale (GCS); time to presentation; season and day of injury; emergency room, intensive care unit, and total length of stay type; and mechanism of injury; and operations. RESULTS: A total of 1,832 pediatric trauma patients were evaluated. Ninety-four children were identified with farm-related injuries. Mean age was 10.75 years. Mean ISS was 7.38. Three children died. Four children wore protective equipment. Forty-four percent of injuries occurred during summer, 31% during spring, and 55% on weekends. Average time to initial presentation was 39 minutes. A total of 177 minutes elapsed before transfer to regional trauma center. Seventy-two children required admission. LOS was 0 to 28 days, mean, 2.76 days. Twenty-six children (28%) required operations. Injuries included dislocations/fractures (52%), lacerations/avulsions (38%), concussions (31%), contusions (30%), and burns (14%). Mechanism included animals (41%), falls (34%), motor vehicles (28%), all-terrain vehicles (20%), and firearms (4%). CONCLUSIONS: Farm injuries occur most commonly during weekends, summer, and spring months, resulting in significant morbidity. Most injuries required hospitalization. Unless unstable, initial transfer to a regional pediatric trauma center should result in the most cost-effective, prompt, and highest quality of care.

Culture of the 'aquatic chicken': present concerns and future prospects.

This is not actually a swimming chicken, but rather a fish that fulfils a similar role for subsistence farmers and can also be farmed on a commercial scale. Like the chicken, the tilapiines are meeting protein needs in an affordable way world-wide. However, present farming strategies are struggling to meet ever-rising consumer demand.

Respiratory disease in industry due to B. subtilis enzyme preparations.

Detergent industry workers are known to become sensitized to enzyme preparations added to the products. In a Canadian plant about 25% of 644 employees exposed to airborne commercial B. subtilis enzyme preparations became sensitized. Skin tests with a number of antigens, including purified enzyme preparations, illustrated differences from person to person in the components to which there was sensitization. The presence of respiratory symptoms related to the industrial exposure was reported much more commonly among sensitized workers. Among employees obliged to miss work, FEV(1) values after 24 months were considerably higher than those obtained during the time of initial difficulties. Blood eosinophilia was observed in sensitized workers. Serum IgG antibodies to the enzyme preparations were demonstrable in most sensitized individuals but did not provide a reliable index of sensitization or of the symptomatic state.