Semblanzas Ictiológicas: Juan Manuel Molina

A través de esta serie intentaremos conocer diferentes facetas personales de los integrantes de nuestra “comunidad”. El cuestionario, además de su principal objetivo, con sus respuestas quizás nos ayude a encontrar entre nosotros puntos en común que vayan más allá de nuestros temas de trabajo y sea un aporte a futuros estudios históricos. Esperamos que esta iniciativa pueda ser otro nexo entre los ictiólogos de la región, ya que consideramos que el resultado general trascendería nuestras fronteras.

Assessment and possible development of the fishery resources of Pedro Bank

Pedro Bank is about 1,300 square miles in extent and lies at the mouth of the Palk Strait close to the mainland, enabling smaller boats to exploit it. Trawl surveys indicated the presence of substantial demersal varieties on the Pedro Bank, but the results of the early commercial operations indicate that a 135-foot trawler may not be operated continuously on the bank without diminishing returns. Subsequent to the commercial operations extensive surveys with smaller boats and various types of gear were carried out. Of the various types of gear tried out, results from bottom long lining and hand lining operations were promising. Trials were carried out to compare these two types of gear. Though not extensive, these trials indicated that at the initial stages of exploitation of the Bank, hand lining, which is extensively practiced in Ceylon, may be better but as exploitation progresses; with more experience, it should be possible to overcome some of the present disadvantages of bottom long lining and eventually bottom long lining should produce better results. The recently introduced mechanised craft are exploiting only the fringe of the bank and it should be possible to exploit its stocks fully with slightly bigger boats with a 35-40 mile range.

Resources of the Wadge and Pedro Banks

Sri Lanka's interest in trawler fishing dates back to 1902 when a Colombo merchant attempted to operate a trawler off Sri Lanka's waters. The next attempt was made in 1907. These attempts did not proceed any further. Between 1920 and 1923 a very comprehensive survey of the littoral waters around the island was carried out. One of the principal aims of the survey was to investigate the possibility of trawler fishing in the seas around. Malpas (1926) and Pearson and Malpas (1926) reporting the results of the survey indicated that the Wadge and Pedro banks were the only areas available for commercial trawler operations and indicated that the fish resources in the two banks could be profitably exploited. Commercial exploitation of the Wadge bank commenced in 1928 and a fishery is now firmly established in the bank. The Marine Biologist and the Director of fisheries in their administration reports and Sivalingam and Medcof (1957) and the author (1965) have reported on the progress of the Wadge bank fishery. Some of the trends indicated by an analysis of the records of the commercial trawling operations are further discussed in this paper.

Comparison of physicochemical properties of muscle proteins in cultured and wild prawns (Penaeus (Fenneropenaeus) orientalis Kishinouye, 1918)

Protein physicochemical properties in cultured and wild prawns (Penaeus (F.) orientalis Kishinouye, 1918) were studied and compared. Protein fractions were separated into water-soluble, salt-soluble, alkali-soluble, and stroma. The results showed that salt- and alkali-soluble proteins were slightly higher in wild prawns and water-soluble proteins were higher in cultured prawns. There were only slight differences in Ca2+-ATPase, MG2+-ATPase, and ATP sensitivities. The textural values of wild prawns were significantly higher than the cultured ones.

Comparison of physicochemical properties of muscle proteins in cultured and wild prawns (Penaeus (Fenneropenaeus) orientalis Kishinouye, 1918)

Protein physicochemical properties in cultured and wild prawns (Penaeus (F.) orientalis Kishinouye, 1918) were studied and compared. Protein fractions were separated into water-soluble, salt-soluble, alkali-soluble, and stroma. The results showed that salt- and alkali-soluble proteins were slightly higher in wild prawns and water-soluble proteins were higher in cultured prawns. There were only slight differences in Ca super(2+)-ATPase, MG super(2+)-ATPase, and ATP sensitivities. The textural values of wild prawns were significantly higher than the cultured ones.

Morphology, biometry and distribution of Difflugia biwae Kawamura, 1918 (Protozoa : Rhizopoda)

The freshwater testate amoeba Difflugia biwae Kawamura, 1918, isolated from Mulan Lake, Hubei Province, China is investigated using light microscopy and scanning electron microscopy. The morphology, biometry and distribution of this little known species are supplied. After careful comparison with three other similar species, including D. delicatula Gauthier-Livre et Thomas, D. elegans Penard and D. oblonga caudata Stepanek, we believe that the characteristics of smooth fusiform shell, conspicuous great collar flare (always larger than body-width) around the aperture, constriction behind the aperture and a somewhat curved aboral horn set D. biwae apart from all other Difflugia species. This species shows a great diversity in total length, collar height and aboral horn length which have high variability (CV between 11.76 and 24.52). However, body width, collar diameter, neck width, body length and aperture diameter are fairly constant with low variability (CV between 5.34 and 8.79) which shows a remarkable uniformity of D. biwae. Also, the size frequency distributions of both body width and body length yield bell-shaped (normally distributed) curves and indicate that D. biwae is a size-monomorphic species, characterized by a main-size class and a small size range. D. biwae is probably endemic to East Asia (China and Japan) because it has such a large size (165-306 mu m) that it would have been easily found in Europe and North America, if it were there. Consequently, D. biwae must have a restricted geographical distribution, disproving the old hypothesis that microscopic organisms are cosmopolitan.

Evolução agro-socio-econômica dos agricultores e da agricultura de Machadinho d´Oeste em Rondônia, entre 1986 e 1999.

Com o objetivo de melhor compreender as transformações agrícolas da Amazônia e suas consequências, a Embrapa Monitoramento por Satélite vem pesquisando há quase 15 anos na região de Machadinho d´Oeste, no nordeste do Estado de Rondônia, um grupo significativo de produtores rurais. O trabalho é de longo prazo, com duração prevista para 100 anos. Um novo perfil agrosocioeconômico dos agricultores e da agricultura praticada nesta região foi realizado, em outubro de 1999, junto às propriedades estudadas nos anos anteriores (1986, 1989, 1993 e 1996). Os indicadores quantitativos, levantados, tratam-se da evolução dos processos socioeconômicos e ambientais extremamente relevantes como o desmatamento, a capitalização dos produtores, a concentração de terras, o uso de tecnologias modernas.

Evolução da produtividade agrícola em floresta tropical úmida, entre 1986 e 1999: o caso de Machadinho d´Oeste-RO.

Este trabalho analisa a evolução da produtividade agrícola em relação à tipologia dos solos de cerca de 455 produtores rurais, que vêm sendo acompanhados anualmente por imagens de satélites a cada três anos, através da aplicação de questionários com informações agroambientais e socioeconômicas em campo, desde 1986, na floresta tropical úmida em Machadinho d´Oeste, Rondônia. Em 1999, dando continuidade ao trabalho de monitoramento da pequena agricultura nesta região, um novo levantamento foi realizado, sobre os sistemas de produção agrícolas praticados, aliado ao levantamento e tratamento dos solos agrícolas das propriedades pesquisadas quanto às características químicas, físicas e morfológicas dos mesmos.

Análise exploratória e dinâmica espaço temporal dos sistemas de produção em Machadinho d' Oeste (RO), entre 1986 e 2005.

2007

Estimativa de emissões de gases de efeito estufa provenientes da queima de residuos da cana-de-açúcar no estado de São Paulo no período de 1986 a 2008.

2010

Resultados de pesquisa de soja 1986/87.

Agrometeorologia; Entomologia; Fertilidade do solo e microbiologia; Fitopatologia; Genetica e melhoramento; Manejo da cultura; Plantas daninhas; Tecnologia de sementes; Metodos quantitativos; Difusao de tecnologia; Informacao e documentacao; Assessoria de imprensa.

Recomendacoes tecnicas para a cultura da soja no Parana 1986/87.

Investimentos em tecnologia: a nova realidade da nova agricultura; Manejo do solo; Clima; Cultivares; Populacao, densidade e epocas de semeadura; Instalacao da lavoura; Controle de plantas daninhas; Manejo de pragas; Controle de doencas; Colheita.

Avaliação de danos de uma exploração florestal em área de reserva legal no projeto de colonização Pedro Peixoto, Acre.

A Embrapa Acre iniciou, em meados de 1995, um projeto de manejo florestal sustentado para pequenas propriedades, tendo como principal característica a prescrição de uma intervenção de baixo impacto sobre a floresta por meio de "métodos artesanais" de exploração de madeira. Estes métodos consideram os poucos recursos materiais de que dispõem os pequenos produtores.