Modification of the biological intercept model to account for ontogenetic effects in laboratory-reared delta smelt (Hypomesus transpacificus)*

We investigated age, growth, and ontogenetic effects on the proportionality of otolith size to fish size in laboratory-reared delta smelt (Hypomesus transpacificus) from the San Francisco Bay estuary. Delta smelt larvae were reared from hatching in laboratory mesocosms for 100 days. Otolith increments from known-age fish were enumerated to validate that growth increments were deposited daily and to validate the age of fish at first ring formation. Delta smelt were found to lay down daily ring increments; however, the first increment did not form until six days after hatching. The relationship between otolith size and fish size was not biased by age or growth-rate effects but did exhibit an interruption in linear growth owing to an ontogenetic shift at the postflexon stage. To back-calculate the size-at-age of individual fish, we modified the biological intercept (BI) model to account for ontogenetic changes in the otolith-size−fish-size relationship and compared the results to the time-varying growth model, as well as the modified Fry model. We found the modified BI model estimated more accurately the size-at-age from hatching to 100 days after hatching. Before back-calculating size-at-age with existing models, we recommend a critical evaluation of the effects that age, growth, and ontogeny can have on the otolith-size−fish-size relations

Charts for the rapid estimation of percentages of plants and/or animals in samples

The need to estimate percentages and/or numbers occurs frequently during practical research work; accurate but rapid estimates can be useful when planning research programmes. Charts are provided that may be used as a visual aid to estimating numbers of animals/plants in a specific situation, for example, the number of fish fry in a subsample from a hatchery tank, or the percentage composition of a sample such as the percentage algal cover in a pond.

Genetic improvement of the herbivorous blunt snout bream (Megalobrama amblycephala)

Selection experiments with the herbivorous blunt snout bream or Wuchang bream (Megalobrama amblycephala) were started in 1985. Mass selection for size and length/depth ratio resulted in a significant increase in growth and better shape, while inbreeding led to a significant decrease in growth. The total selection ratio from fry to mature brooders was about 0.03 per cent per generation. In the grow out stage, the average daily body weight gains of two lines of fifth generation (F5) fish were 29 per cent and 20 per cent respectively more than the control group, with an average of 5.8 per cent and 4 per cent improvements per generation, respectively. The body was 4 per cent deeper in ratio of standard length/body depth. The effects of inbreeding were examined by crossing full-sibs, the offspring of which were kept without selection. The third generation inbred fish showed 17 per cent lower growth as compared to the control group, with an average of 7.5 per cent per generation. The results demonstrate that selection is a powerful tool to improve the economic traits of the blunt snout bream, but inbreeding can rapidly lead to a reduction in performance. In 2000, the 6th generation of selected bream was certified by the Chinese Ministry of Agriculture as a good breed for aquaculture.

Da invisibilidade à vulnerabilidade: percursos do corpo lésbico na cena contemporânea brasileira face à possibilidade de infecção por DST e AIDS

A produção acadêmica motivada pela epidemia de HIV e Aids impulsionou as pesquisas relativas à sexualidade configurando novos campos de investigação, em especial sobre os gays. No entanto, não é significativa no Brasil a produção acadêmica que aborde a vulnerabilidade às DSTs a partir da identidade lésbica. A saúde sexual das mulheres presumidamente heterossexuais tendeu a permanecer subsumida à exclusiva preocupação com a reprodução ao longo da trajetória das políticas de atenção à saúde das mulheres, mesmo frente à Aids. De forma ainda mais acentuada que a sexualidade feminina heterossexual, a homossexualidade feminina tendeu à invisibilidade na sociedade brasileira e frente ao discurso médico-ginecológico. O advento da epidemia contribuiu para a manutenção desta invisibilidade por força da crença de que o corpo lésbico seria o único infenso à infecção pela via sexual. Nesta tese busca-se compreender a transformação discursiva do corpo lésbico dos primeiros tempos da epidemia até hoje. Mais especificamente, como um corpo imune à epidemia está calcada na idéia de que a vulnerabilidade das lésbicas é o passaporte para a afirmação/inclusão de um dado marco identitário na agenda de políticas públicas. Nesse sentido, o campo em que se desenha a disputa do corpo lésbico face às DST/Aids é marcado pela tensão entre prática sexual e identidade sexual.

Através e apesar da reconstrução nacional em Angola: circunstâncias e arranjos nos limites da vida

A "reconstrução nacional" de Angola impressiona pela magnitude de seus empreendimentos visíveis. Esta Tese trata de travessias conduzidas por diferentes atores sociais "através" e "apesar" da "reconstrução nacional". A partir de micronarrativas de algumas pessoas que compõem a "Angola" contemporânea e que, em algum momento, foram minhas interlocutoras, sigo por caminhos que operam como chaves interpretativas para traçar os sentidos e os significados do pós-guerra no país. Para transitar "através da reconstrução nacional" é necessário ser re-conhecido, não apenas por políticas repressivas e de gestão de populações, mas também como sujeito de direitos. Aqueles que não obtiveram este re-conhecimento agenciam as brechas existentes em seus campos de possibilidades, "apesar da reconstrução nacional". Entre arranjos circunstanciais e (não) re-conhecimentos alguns ocupam, situacionalmente, a condição de borderlander. E "através" e "apesar" pessoas constroem suas vidas enquanto a nação se reconstrói.

Lune, Wyre & Furness Fisheries Advisory Committee 4th July, 1977.

This is the report from the Lune, Wyre and Furness Fisheries Advisory Committee meeting, which was held on the 4th July 1977. The report looks at comments of the Regional Fisheries Officer on the report on specific matters such as different river stretches and water quality. It also includes sea-trout ova and fry propagation and re-stocking programmes carried out and planned in determined rivers: Kent, Leven, Crake, Duddon, Keer and Eea. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

Eden & District Fisheries Advisory Committee 19th October, 1976.

This is the report from the Eden and District Fisheries Advisory Committee meeting, which was held on the 19th October, 1976. The report contains sections on fish stocking, the drought situation, fisheries activities, the protection of salmon and trout fry from cormorants and mergansers feeding on these fish, and water conditions harmful to fish life. The section on fish stocking includes background information about fish stocking by the authority; difficulties; migratory fish; non-migratory trout and coarse fish; stocking after pollution; stocking of waters within the region; stocking with coarse fish; and recommendations. The section on fisheries activities includes general information on the Eden and District Area; stocking; fish rescues; fish mortalities; Holmewrange hatchery; fry stocking; disease; and smolts. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

Eden and District Fisheries Advisory Committee 29th June, 1976.

This is the report from the Eden and District Fisheries Advisory Committee meeting, which was held on the 29th June, 1976. The report contains sections on fisheries activities and validity of Rod Licences. The section on fisheries activities during the period 13th January-3rd March includes fishing and coarse fish; stocking; biological surveys; mortalities; poaching; scale reading and a report on salmon scale return in the River Eden. The section on fisheries activities during the period 3rd March-23th May includes a general report of the Eden and District fisheries; fish kills; stocking; fish transfer/rescue; obtaining of ova, fry rearing; and fry stocking. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South & West Cumberland Fisheries Advisory Committee 28th June, 1976.

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 28th June, 1976. The report contains sections on Branthwaite Weir and fisheries activities. The section on fisheries activities during the period 13th January-2nd March includes stocking; biological surveys; fish mortalities; hatcheries and redd counting. The section on fisheries activities during the period 2nd March-20th May includes a general report of the area; fry stocking/rearing; River works (River Ehen, Calder, Derwent, and Glenderamackin); coarse fish removal; and fish transfers. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

Lune, Wyre & Furness Fisheries Advisory Committee 30th June, 1980

This is the report from the Lune, Wyre and Furness Fisheries Advisory Committee meeting, which was held on the 30th June, 1980. It includes the report by the area fisheries officer on fisheries activities which comments on river conditions and fishing for salmon, sea trout and brown trout, and the recorded numbers of fish which passed through Duddon Hall, Haverthwaite, Halton, Broadraine and Basinghyll fish counters. Also covered in the report is an update on Middleton Hatchery which includes the numbers of salmon, sea trout and brown trout fry planted for various waters including the Lune, Keer, Duddon and Kent Catchment, and an update on the cage rearing of smolts for the River Leven. Finally the report adds fish mortalities, the pipeline project with the British Gas Corporation and the Rivers Leven and Kent fish distribution survey map. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

River Dart Salmon Project. Summary of Phase I report.

This is the River Dart Salmon Project Summary of Phase I Report (2002) by the Westcountry Rivers Trust. The report contains sections on the introduction to Dart Salmon, factors affecting salmon numbers, salmon rod catch and salmon electro-fishing data, and a summary and discussion of the next phase. It also contains two tables with time series analysis on fry/parr numbers in representative section of the River Dart and figures with trends in fry/parrs numbers at juveniles electro-fishing sites. The section on salmon rod catch data includes trend analysis, cross-correlation of catches in different rivers and a general conclusion.

River Dart Salmon Project. Summary of Phase II report.

This is the River Dart Salmon Project Summary of Phase II Report (2002) by the Westcountry Rivers Trust. The report contains sections on the project introduction, methods, habitat utilisation (predicted densities) and distribution at Walla Brook, Swincombe and Strane, bio-monitoring of water chemistry and suggested action at local, catchment and research scale. The attached maps show spawing, fry and juveniles habitats in the lower or upper Walla Brook.

A report on the strategic stock assessment survey of the Colton Beck catchment 1994 with particular reference to salmonids

This is the report on the strategic stock assessment survey of the Colton Beck catchment in 1994 with particular reference to salmonids in Colton Beck, River Ea, River Gilpin and Rusland Pool. This report forms one part of the third year of a triennial survey programme for the South West Cumbria and South Cumbria catchments. It was produced by the National Rivers Authority in 1994. Colton Beck had excellent densities of sea trout (Salmo trutta) and a small population of salmon (Salmo salar) in its lowest reaches. The total productivity was very good throughout the catchment. Stocking of sea trout fry in 1993 has enhanced the population with survivors through to parr probably adding to the scoring of double class A at two sites in the survey in 1994. Stocking was not undertaken in 1994, but the population appears to be maintaining itself at a very high level.

A report on the strategic fisheries stock assessment survey of the River Winster 1995 together with a coarse fish survey in 1994 and reference to the 1995 drought

This is the report on the strategic fisheries stock assessment survey of the River Winster 1995 together with a coarse fish survey in 1994 and reference to the 1995 drought, produced by the Environment Agency North West in 1996. Salmonid production within the Winster catchment was dominated by trout although good densities of salmon juveniles were found on some main river sites. Despite suffering drought conditions for much of 1995, only salmon fry production appeared to have been affected. Coarse fish populations once found in the lower reaches of the Winster appear to have declined to very low levels with no fish sampled. This may be partly due to broken tidal gates allowing saline intrusion. It seems that the lower river was suited to the development of a recreational coarse fishery, now that the gates have been repaired. This report completes the strategic stock assessment surveys planned for the period 1992-1995. It represents the last major catchment that was surveyed to determine the current status of fisheries in the South and South West Cumbria areas.

River Avon (including Glazebrook) fisheries survey 1978

This is the River Avon (including Glazebrook) fisheries survey 1978 report produced by South West Water Authority in 1978. This report aims to determine the penetration of Salmon into the River Avon system and to a lesser degree estimate the population of resident salmonids and other indigenous species. Six sections were electro fished at accessible points as detailed below. All fish were identified and measured. Each section was fished through three times to take the majority of the resident species. Small specimens of salmonid fry, eels and lamprey were common in almost all River Avon sections with the exception of Shipley bridge and Avon Dam but due to the mesh size of the standard dip nets used, many slipped through making accurate number estimation impossible.