Information collected in Teesdale concerning free-swimming stages of brown trout (Salmo trutta L.)

During 1978 and 1979, electrofishing surveys were made in Teesdale - both to provide background information for ecological work on the streams, and to provide data so that the influence of discharge regime on the fish population densities could be examined. The discharge regimes of the different streams were compared using the Base Flow Index (BFI) as developed by the Institute of Hydrology. (PDF contains 30 pages)

Juvenile salmon investigations River Wenning catchment 1981-86

As part of the River Lune juvenile salmonid investigation, a number of sites on the River Wenning catchment were electrofished annually from 1981 - 1985. Particularly low Salmon parr populations were evident for much of the Wenning catchment which has caused some concern. All the Wenning catchment electrofishing results are reported in this paper and comparisons are made with designated groups of sites on the remainder of the Lune catchment. These groups of sites are: River Lune and tributaries, upstream Tebay, Upper Middle Lune, Lower Middle Lune, Lower Lune, Birk & Borrow Becks, Chapel & Crosdale Becks, Rawthey system, Barbon & Leek Becks and the Greta system. The general scarcity of Salmonids in large sections of the main river Wenning probably reflects the apparent limited natural spawning areas on the catchment. Details of Salmon fry and ova planting on the Wenning catchment since 1981 have been collated and whilst survival through the 0+ stage appears to be quite good, recruitment to the 1++ stage appears to be poor. Water quality does not appear to be responsible for the very low salmonid densities at some main river sites but is possibly a factor in apparently preventing any Salmon run in Keasden Beck. Recommendations for future Fisheries and Biological work are given.

A summary report on juvenile salmonid populations of the River Lune catchment, 1981 to 1991

This report summarises the fisheries electrofishing survey work undertaken on the River Lune, England, in the period 1981-85 and 1991. As part of a long term monitoring programme by the National Rivers Authority, juvenile surveys, with the emphasis on salmonids, have been carried out on the River Lune on a number of occasions since 1981. The latest survey in 1991 now gives the opportunity to assess what, if any, changes have occurred in the juvenile populations across the last 11 years and how future fisheries management may impact on the River Lune as a fishery. The areas of trout and salmon, fry and parr production will be considered in detail, as will adult trout populations. Water quality issues will be mentioned briefly as will habitat issues, where they are deemed to be important in affecting fish densities.

An assessment of the efficiency of three active fish capture methods and a study of roach / bream hybrids on the Crossens drainage system near Southport.

An assessment of three methods of fish capture, to establish the best fishing method which reflects the best range of sizes and species of fish in a given area. The methods used were trawl netting, electrofishing, and seine netting which were assessed on the Crossens drainage system near Southport. The report also includes a study of roach / bream hybrids that were found at the site, which focuses on their distinguishing features and compared with the features of roach and bream.

Report on eight weeks at the Fisheries Department of the Lancashire River Authority [including a Leeds / Liverpool Canal survey]

This report looks at the interests of the Fisheries Department for the Lancashire River Board, focusing on the Liverpool and Leeds Canal Survey. It looks at finding parasites in fish from an electrofishing survey (roach and perch). This was to contribute towards the main survey with a possible view to suggesting whether or not the parasites were one reason for the poor fish population. Methods of finding parasites are given, and results of what parasites that were found in the fish are discussed.

An investigation into the effects of electric fishing equipment on salmon and sea trout within the area of the Lancashire River Board.

The report looks at experiments into electric fishing equipment and effects on salmon and trout within the Lancashire River Board. Experiments include obtaining information on voltage gradients, ascertaining what damage to fish of the larger size groups resulted from electric fishing, determining whether or not fractures could occur in coarse fish and brown trout,similar to those occurring in salmon and sea trout, and effects low temperatures have on electrofishing techniques.

Composição elementar corporal, desbalanço alimentar e reciclagem de nutrientes em peixes de um riacho costeiro de Mata Atlântica

No presente estudo foi avaliada a variação na dieta e na composição elementar corporal (C:N:P) de oito espécies de peixes que coocorrem em dois trechos de um riacho. Além disso, foram investigadas as diferenças na demanda e excreção de nutrientes por duas espécies de Loricariidae, sendo uma nativa (Hypostomus punctatus) e a outra não nativa (Parotocinclus maculicauda). As coletas foram realizadas no rio Ubatiba, através de pesca elétrica em diferentes meses entre os anos de 2010 e 2012. A partir da análise alimentar, observamos que as espécies apresentaram variação na dieta entre as localidades, com exceção das duas espécies de Characidium. Apesar destas variações, o presente estudo corroborou a hipótese de homeostase estequiométrica corporal. A exceção foi a espécie Hoplias malabaricus que apresentou variação na concentração elementar corporal e alto desbalanço alimentar entre as localidades, sendo as diferenças mais acentuadas na área aberta. Analisando as diferenças na demanda nutricional dos Loricariidae verificamos uma maior concentração corporal de carbono e nitrogênio para a espécie nativa e maior de fósforo na espécie não nativa, sendo essa diferença confirmada por um maior consumo de fósforo pela espécie não nativa. A análise da excreção revelou que a espécie nativa excreta mais nitrogênio e fósforo que a não nativa. Sendo assim, os resultados sugerem que a espécie não nativa apresenta uma requisição de fósforo maior do que a nativa. Logo, ambientes com altas concentrações de nutrientes, tal como o riacho estudado, podem favorecer o estabelecimento desta espécie

Movimento longitudinal de peixes: uma análise cienciométrica, manutenção de comunidades e implicação na colonização de um riacho costeiro

Este trabalho apresenta uma análise cienciométrica dos estudos sobre movimentos longitudinais de peixes, publicados no mundo entre 2000 e 2010, pondo em vista o cenário geral dos trabalhos desenvolvidos sobre o tema. Além disso, examina os padrões de movimento longitudinal das espécies de peixes de um riacho costeiro de Mata Atlântica, o rio Ubatiba (Maricá-RJ), e analisa a dispersão, distribuição e variação na densidade de uma espécie introduzida nesse riacho, verificando se houve impacto dessa introdução sobre uma espécie nativa. Os 525 artigos analisados na cienciometria foram obtidos através de uma busca realizada na base de dados Web of Science. Observou-se o aumento no número publicações sobre movimentos de peixes. A maior parte dos estudos foi desenvolvida nos EUA. Os ecossistemas mais pesquisados foram rios e riachos e 464 trabalhos analisaram os movimentos a partir do método de marcação, onde a telemetria foi destacadamente a técnica mais utilizada. A família Salmonidae foi o alvo da maioria dos estudos sobre deslocamento. Para identificar os padrões de movimento da comunidade de peixes do rio Ubatiba, experimentos de marcação-recaptura foram realizados em quatro pontos amostrais diferentes no riacho, entre junho de 2011 e abril de 2012. Um total de 1270 exemplares, entre 10 espécies estudadas, foram coletados através de pesca elétrica, identificados, medidos, marcados com implante intra-dérmico de elastômeros coloridos (VIE) e devolvidos no mesmo trecho onde foram coletados. Foram observados movimentos de curta e longa distância. As espécies que percorreram maiores distâncias foram A. tajasica e Characidium sp.. Na estação chuvosa, os peixes tendem a se movimentar mais em direção à montante e a percorrer maiores distâncias. A espécie introduzida P. maculicauda, foi registrada pela primeira vez no rio Ubatiba, em julho de 1999, no ponto amostral mais baixo do riacho, com baixa densidade. Observou-se que ao longo dos anos a espécie introduzida se dispersou, colonizando pontos mais altos do riacho. Além disso, verificou-se uma correlação negativa entre as densidades da espécie introduzida e da espécie nativa H. punctatus

Mersey & Weaver Fisheries Advisory Committee 22nd October, 1975.

This is the report from the Mersey and Weaver Fisheries Advisory Committee meeting, which was held on the 22nd October 1975. The report contains information on a report by the divisional scientist on fisheries activities, importation of live freshwater fish, drainage representation on local committees, new byelaws and fishing licence duties. The report by the divisional scientist looks at permissions for stocking and electrofishing, biological work and results of fish toxicity tests carried out in Rivers Bollin, Etherow, Glaze and Tame. It also contains records of fish mortalities. 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 27th June, 1977.

This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 27th June, 1977. The report contains sections on water resources development in West Cumbria which includes essential short and long term requirements for conservation of migratory fish stocks in the River Ehen. The section on fisheries activities includes salmon, sea trout and brown trout catches; restocking; fish mortalities; fisheries investigations/gravel abstractions in Rivers Annas, Calder, Esk, Newlands Beck, St. John's Beck, Trout Beck and Caldew; and general activities held in Holmwrange Hatchery. It also covers prosecutions and electrofishing carried out in Rivers Cocker, Marron, Ellen, Glenderaterra, Ehen, Calder, Irt, Esk and Annas. 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 Teign Fisheries Survey 1979

This is the River Teign Fisheries Survey from August 1979 by the South West Water Authority. The River Teign was sampled by electrofishing at fifteen sites and population estimates, average lengths, weights and biomass were calculated for each species present, and where possible for individual age classes of those species. Results indicated that a stable community structure existed, and little had changed from 1963. Salmonids accounted for the majority of the biomass, and within this group trout were the most abundant in the headwater, and salmon in the lower reaches. All tributaries sampled had higher densities and biomass than the main river. The results were compared with other data collected from similar surveys of other rivers in Devon by the South West Water Authority. Both the average length of each age class, and the biomass in the main River Teign appeared to be lower than in most other rivers, although in the Rivers Wray and Lemon these values were particularly high.

The assessment and exploitation of eel (ANGUILLA ANGUILLA. L) stocks in the River Thames and its catchment.

This is the assessment and exploitation of eel (Anguilla anguilla. L) stocks in the River Thames and its catchment performed by the Polytechnic of Central London and The Thames Water Authority Research Project between April 1985 and April 1986. The report makes an examination of the pre-pollution history of the Thames eel fishing industry to permit an assessment of the recovery of the eel stock following the cleaning up of the Tideway. Archive material shows that the 19th Century stock was larger and more widely distributed than it is today, and the natural recruitment of elvers to the system is now much smaller. Sampling of commercial catches and trapping studies, including comparisons of different mesh sizes, have been undertaken in order to develop a statistical model of the Inner Estuary eel stock and its fishery. Local migrations and activity throughout the year are studied. Electro—fishing methods and eel traps are compared using mark-recapture techniques in order to develop an accurate means of assessing relative abundance and distribution. Work so far has concentrated mainly on the Rivers Darent and Roding but a preliminary distribution map for the whole catchment has been prepared. An experimental trapping site was established on the River Darent to investigate natural recruitment and up—river migration of elvers and juvenile eels. 1790 small eels were taken in 1985 providing information on the scale, timings and factors affecting the migration.

Report on fisheries invertebrate survey of the Groove Beck,Thornsgill Beck,Troutbeck system

This is the Report on fisheries invertebrate survey of the Groove Beck, Thornsgill Beck and Troutbeck system produced by the Environment Agency North West in 1997. In 1996 the National Rivers Authority (NRA) report on the 1992 strategic stock assessment for the Upper Derwent catchment Jane Atkins recommended that should subsequent electrofishing show continued low densities, a survey of the invertebrate fauna should be undertaken to assess the food availability for salmonids, in order that lack of food could be ruled out as a contributory factor in their poor breeding success. Additionally the survey looked at the substrate to try to determine whether the bed type might actually be unsuitable for spawning, especially in view of the previously mentioned silt inputs.

Preliminary experiments on electrical fishing in fresh watter [i.e. water]

Fishing using electricity is a new technique and is still in the experimental stages in many of the advanced countries. While no published records are available in India, considerable work has been done in Germany, United States, Canada, and United Kingdom. These papers mainly deal with the behavior of the fish in the electrical field, the physiological effects of electrical current on fishes, methods of electrofishing, electric fencing etc. The following experiments on electrical fishing were conducted with a view to studying the distribution of electrical field when an alternating current is passed through two fixed electrodes in fresh water and to study the reaction of different fresh water fishes to the field.

Study on some biological and feeding factors of spined loach Cobitis taenia from the Babolrud, Talar and Siahrud Rivers

Spined loach, Cobitis taenia, is a predominant fish in the river systems of the southern Caspian Sea basin. Although there is evidence of the geographical divergence of this taxon, but no information is available on morphological differences within the species populations. This study was designed to evaluate some biological factors including; morphometric and meristic characters, length-weight, age-growth, condition factor, diet, reproduction, variation and differentiation, in the Babolrud, Talar and Siahrud Rivers in south of the Caspian Sea basin. Age, sex ratio, fecundity, ova diameter and gonadosomatic index were estimated. Also, regression analyses was tested the relation between fecundity and fish length, weight, gonad weight, and also age. Totally 858 fish of which 721 were matures, were collected from these rivers by electrofishing. 37 morphometric characters, 9 meristic characters and 78 truss network system characters were estimated. Resulats of DFA analysis based on data of morphometric and meristic showd that these populations are highly (94.5%) varios from each other. In discriminate function analysis, the proportion of individuals correctly classified into their original groups was 61%, 65.4% and 86.5% for upstream and downstream, respectively. Clustering based on Euclidean distances among groups of centroids using an UPGMA and also principal component analysis’ results for morphometric data indicated that these populations from these three rivers were clearly distinct from each other. Regression equations between length and weight in these three populations were significantly different from Folton factor (b=3), that showed the fish has a negative Alometric growth process. Condition factor was estimated between 0.8912 to 1.2736 and 0.8131 to 1.4489 for males and females, respectively. Sex ratio (female: male) in these populations was 1.2816:1. The difference between the number of females and males was significant and females were more than males. The female and male specimens reach maturity by Tl more than 40 and 30 mm and at the age of 2+ and 1+, respectively. The mean of ova diameter was 0.5824±0.2882. The spawning took place from May to late July, at the water temperature from 18.7 to 24.0°C. The GSI values average at the beginning of the reproduction period was about 9%, with ranged from 2 to 26% in ripe mature females. The absolute and relative fecundity were 2109±792 and 579±208 respectively. The absolute fecundity was significantly related to body weight and gonads weight. Based on the pattern of gonado-somatic index, it was concluded that this fish has prolong active reproductive period, which is a type of adaptation by short-lived small fishes to environmental conditions. The macroscopic and histological results showed that the female and male have 5 and 4 stages in their maturation process, respectively. The RLG index was about 0.4732, which showed the fish is a carnivorous species. Significant difference was observed between fishes with different length and diet. The main foods of the fish were Trichoptera, Chironomidae larvae and Ephemeroptera which were their prefered food as well, however it was estimated that the food selection and diet are affected by environmental conditions.