A sonar fish counter

Braithwaite, H.

doi:10.1111/j.1095-8649.1971.tb05906.x

Cited by 14 publications

(5 citation statements)

References 2 publications

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“…Stewart (1969) reported greater movement and catches on falling river levels and less movement on steady flows. This conclusion appeared to be supported by some data obtained from the River Frome during a period of receding flood (see Braithwaite, 1971, Fig. 8, p.…”

Section: Discussionsupporting

confidence: 73%

The upstream migratory behaviour of salmonids in the River Frome, Dorset

Hellawell

Leatham

Williams

1974

Journal of Fish Biology

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Data on the migratory behaviour of salmonids were collected at a gauging weir by means of a restivity fish-counter which triggered a motor-driven 35 mm still camera to provide photographic records of passing fish. A clear bimodal seasonal pattern of movement was observed in three consecutive years with peaks during June-August and October-December. Daily variations in the rate of movement could not be correlated with changes in discharge or temperature. Salmonids tended to move at discharges lower than those generally available. This contrasts with other published work and was attributed to themoreequitable flow-pattern of chalk rivers. There was no optimal temperature associated with move ments. Some evidence suggested that the largest fish moved earlier in the year but this was not marked. In clear water most movement occurred during the hours of darkness but during floods, when the river was turbid, the diurnal pattern tended to be reversed with greatest movement during the hours of daylight. Most fish negotiated the weir close to the bottom, well below mean velocity, and took a central path through the flume. Although analysis of upstream migratory behaviour was hindered by the lack of data on the numbers of fish available below the counting point it was concluded that the basic pattern of migration is established by time (season). Changes in discharge, light intensity and other parameters may then play a secondary role in modifying the details of the pattern but attention is drawn to records of movements in regulated flows where a remarkably constant pattern is shown from year to year.

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Section: Discussionsupporting

confidence: 73%

The upstream migratory behaviour of salmonids in the River Frome, Dorset

Hellawell

Leatham

Williams

1974

Journal of Fish Biology

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“…With two dual‐beam systems located side by side with slightly offset elliptical transducers and transmitting alternately, the direction of travel could be determined by observing which transducer beam the fish entered first. Most early dual‐beam acoustic studies in rivers were applied to adult salmonid migrations (Braithwaite 1971; Mesiar et al . 1990; Johnston and Hopelain 1990).…”

Section: Capture Independent Methodsmentioning

confidence: 99%

Methods for studying spatial behaviour of freshwater fishes in the natural environment

2000

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Spatial behaviour of fishes in fresh and brackish water ranges in temporal scales between localized diel movements, often associated with foraging and predator evasion, to seasonal or life‐cycle related events involving movements between freshwater habitats or freshwater and marine biotopes. Recent technological advances have resulted in dramatic improvements in the range of techniques available for the study of spatial behaviour of freshwater fishes in the natural environment, and broadly may be divided into two categories: capture dependent and capture independent. The former incorporates those methods that rely on sampling marked fish (mark–recapture) or unmarked fish (density estimates, catch per unit effort) over defined scales of time and space in order to derive information on distribution and movement. Captured fish may also be tagged with transmitters that radiate energy, enabling the fish to be tracked and/or environmental data to be gathered. Biochemical analysis of samples from fish, requiring non‐destructive sampling (genetic analysis and scale microchemistry) or destructive sampling (otolith microchemistry) may also provide information on migration and ontogenetic processes. Capture independent techniques include visual observation and video techniques, hydroacoustics and automated fish counting. Catch per unit effort and mark–recapture techniques are most efficient where long‐term fishery or monitoring studies are in place and data on crude spatial and temporal scales are acceptable. They also have the advantages of low technical requirements and low equipment costs. Where specific management or ecological questions are pertinent, recapture independent techniques may be more appropriate. Telemetric methods can provide high resolution information at the individual level, while hydroacoustics is increasingly providing information at the population level in large lake and river environments. Biochemical methods are becoming increasingly useful in determining the extent of population segregation, where DNA analysis is used, and in the study of migration and ontogenetic changes in behaviour, where otolith microchemistry and stable isotope analysis is used.

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“…The study of anadromous fish migrations via hydroacoustic equipment was started in 1960-1970. At that period the studies were focused on the direction and rhythm of fish migrations in the area of operation of hydrotechnical facilities (Tesch, 1964;Braithwaite, 1971Braithwaite, , 1975Kristinsson and Alexandersdottir, 1978) and were associated with hydroconstruction (Poddubnyi, 1971;Pavlov, 1979Pavlov, , 1989. The accounting systems used were based on various physical principles, but the observations were made mainly in anthropo-genically-transformed environments.…”

Section: Discussonmentioning

confidence: 99%

Hydroacoustic Studies of the Migration of Anadromous Rainbow Trout Parasalmo mykiss (Salmonidae) in the Kvachina River (Western Kamchatka)

Borisenko

Павлов²,

Кузищин³

2022

J. Ichthyol.

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The NetCor research hydroacoustic system has been used to study the anadromous migration of the rainbow trout Parasalmo mykiss (Walbaum, 1792) in the Kvachina River (Western Kamchatka) during its autumn entry from the sea. The intensity of the fish movement increases in similar periods of the neighboring years (2010–2011), which indicates the cyclical migration of the species associated with changes in temperature and water level in the river. The daily dynamics of the movement is characterized by two periods of increased intensity of migration: the first is timed to dawn, while the second begins in the evening hours. The extrapolation of the obtained data provides the estimated numbers of the rainbow trout abundance in the river: 9832 and 2855 individuals in 2010 and 2011, respectively. The difference in the abundance of anadromous rainbow trout in the neighboring years probably results from the peculiarities of the geomorphology and hydrological regime of the river.

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A sonar fish counter

Cited by 14 publications

References 2 publications

The upstream migratory behaviour of salmonids in the River Frome, Dorset

The upstream migratory behaviour of salmonids in the River Frome, Dorset

Methods for studying spatial behaviour of freshwater fishes in the natural environment

Hydroacoustic Studies of the Migration of Anadromous Rainbow Trout Parasalmo mykiss (Salmonidae) in the Kvachina River (Western Kamchatka)

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