Length-weight relationship of small pelagic fish species of the southeast and South Brazilian Exclusive Economic Zone

The length-weight relationship (LWR) parameters of 23 small pelagic fish species (belonging to 13 families) from the south-southeast Brazilian Exclusive Economic Zone in 1996 and 1997 are presented. The b values varied between 2.72 and 3.53. The samples for this study were collected during hydroacoustic surveys covering an area of 700 000 square km.

Physico-chemical factors and bacteria in fish ponds

Analyses of pond water and mud samples show that nitrifying bacteria (including ammonifying bacteria, nitrite bacteria, nitrobacteria and denitrifying bacteria) are in general closely correlated with various physico-chemical factors, ammonifying bacteria are mainly correlated with dissolved oxygen; denitrifying bacteria are inversely correlated with phosphorus; nitrite bacteria are closely correlated with nitrites, nitrobacteria are inversely correlated with ammoniac nitrogen. The nitrifying bacteria are more closely correlated with heterotrophic bacteria. Nitrobacteria are inversely correlated with anaerobic heterotrophic bacteria. The correlation is quite weak between all the nitrite bacteria which indicates that the nitrite bacteria have a controlling and regulating function in water quality and there is no interdependence as each plays a role of its own. The paper also discusses how the superficial soil (pond mud down to 3.5 cm deep) and different layers of the mud affect the biomass of bacteria. The study shows that the top superficial layer (down to 1.5 cm deep) is the major area for decomposing and converting organic matter.

A database for the industrial trawl fishery of Cote d'Ivoire

Fishery statistics for the industrial trawl fishery of Cote d'Ivoire have been well documented since 1968. However, data processing has changed significantly with time and some of the data files have been lost. In 1997, the Centre de Recherches Oceanologiques d'Abidjan decided to retrieve and process all trawl data available from different sources. This paper gives an overview of the database covering the period 1968 to 1997 and describes its coverage, format, structure and use. The database was developed using MS ACCESS and is a powerful tool for storing information about this fishery, and for analysis of its dynamics over a period of 30 years.

Length-weight relationships of bivalves from coastal waters of Korea

Parameters a and b of the length (L)-weight (W) relationship W = a · Lb are presented for 17 commercial bivalve species collected from the southwest coastal waters of Korea. Estimates of b varied between 2.44 (Atrina pinnata japonica) and 3.31 (Scaphara broughtonii) with a mean of 2.891 (± 0.212). A total of 2 107 specimens were analyzed for this study. The length-weight relationship was isometric in most of the species.

Length-weight relationships of Penaeus monodon reared in semi-intensive culture systems of Kerala, India

The results of a study on length-weight relationships of Penaeus monodon, reared in fertilized ponds in Kerala, India, and fed three different supplementary feeds are presented.

White spot viral disease in penaeid shrimp: a review

The white spot viral disease in penaeid shrimp affects the development of the global shrimp industry. This paper reviews the viruses that cause the disease, the transmission of the virus, diagnosis and preventive measures.

Who's working on Mugil culture

The findings are presented of a survey conducted regarding research on Mugil culture; emphasis was given to publications from the tropics and subtropics, particularly from developing regions. The literature search used ASFA, the ICLARM library and professional staff collections. It was found that during the period 1932-90 there were 203 articles published; of these, 41% were on the subject of reproduction, induced breeding and seed, 26% on culture systems, 12% on general discussions, 11% on diseases/parasites, and 10% on nutrition.

Pegada hídrica de aglomerados subnormais: o caso do Bairro Rocinha / Rio de Janeiro.

A água é essencial à manutenção da vida. No entanto, com as situações de estresse hídrico - disponibilidade hídrica inferior a 1.700 m per capita ao ano (FALKENMARK, 1989) - vivenciadas em diversos pontos do planeta, somadas ao acelerado crescimento da população mundial, os problemas relacionados ao uso da água tendem a aumentar. Neste contexto, a pegada hídrica (PH), que é um indicador de sustentabilidade ambiental, se torna uma importante ferramenta de gestão de recursos hídricos pois indica o consumo de água doce com base em seus usos. O presente trabalho objetiva mensurar a pegada hídrica em função das componentes industrial, doméstica e alimentar da população do bairro Rocinha, um aglomerado subnormal localizado no município do Rio de Janeiro. A pesquisa se deteve a um Estudo de Caso de 20 sub-bairros da comunidade. Sua abordagem foi quantitativa, contando com uma amostra de 203 domicílios, erro amostral de 7% e grau de confiança de 93%. Para tal, foi utilizada como ferramenta de cálculo o modelo Water Footprint Network do ano de 2005. Os resultados indicaram que, em média, a PH dos indivíduos que compõem a amostra é de 1715 m/ano per capita assim divididos: PH de consumo doméstico de água de 175 m/ano per capita (479 l/hab.dia); PH de produtos agrícolas igual a 1470 m/ano per capita, e PH de produtos industrializados de 70 m/ano per capita. Os resultados obtidos sugerem que os indivíduos da amostra com uma maior despesa mensal tendem a ter pegadas hídricas industrial e total também maiores.

An Ecological Perspective on Inshore Fisheries in the Main Hawaiian Islands

A description of fisheries within a depth of 100 fathoms is provided for the eight southeastern-most islands of the Hawaiian Archipelago, known as the main Hawaiian Islands (MHI). These are the inhabited islands of the State of Hawaii and are those most subject to inshore fishing pressure, because of their accessibility. Between 1980 and 1990, an average of 1,300 short tons of fishes and invertebrates were reported annually within 100 fm by commercial fishermen. Total landings may be significantly greater, since fishing is a popular pastime of residents and noncommercial landings are not reported. Although limited data are available on noncommercial fisheries, the majority of this review is based on reported commercial landings. The principal ecological factors influencing fisheries in the MHI include coastal currents, the breadth and steepness of the coastal platform, and differences in windward and leeward climate. Expansive coastal development, increased erosion, and sedimentation are among negative human impacts on inshore reef ecosystems on most islands. Commercial fisheries for large pelagics (tunas and billfishes) are important in inshore areas around Ni'ihau, Ka'ula Rock, Kauai, and the Island of Hawaii (the Big Island), as are bottom "handline" fisheries for snappers and groupers around Kauai and Molokai. However, many more inshore fishermen target reef and estuarine species. Two pelagic carangids, "akule," Selar crumenopthalmus, and "opelu," Decapterus macarellus, support the largest inshore fisheries in the MHI. During 1980-90, reported commercial landings within three miles of shore averaged 203 and 125 t for akule and opelu, respectively. Akule landings are distributed fairly evenly throughout the MHI, while more than 72% of the state's inshore opelu landings take place on the Big Island. Besides akule and opelu, other important commercial fisheries on all the MHI include those for surgeon, soldier, parrot, and goatfishes; snappers; octopus, and various trevallies. Trends in reported landings, trips, and catch per unit effort over the last decade are outlined for these fisheries. In heavily populated areas, fishing pressure appears to exceed the capacity of inshore resources to renew themselves. Management measures are beginning to focus on methods of limiting inshore fishing effort, while trying to maintain residents' access to fishing.