Silver King Creek Paiute cutthroat trout restoration, 1991 through 1993

Silver King Creek, Alpine County, is the native range of the Federally-threatened Paiute cutthroat trout, Oncorhynchus clarki seleniris. Paiute cutthroat currently inhabit Coyote Valley and Corral Valley creeks, which are tributaries to Silver King Creek below Llewellyn Falls, and also Silver King Creek and tributaries aboye Llewellyn Falls. Rainbow trout, O. mykiss, were introduced into the basin during 1949 and became hybridized with Paiute cutthroat. Chemical treatments attempted by the California Department of Fish and Game (CDFG) in 1964 and 1976 failed to eliminate hybrid trout. A chemical treatment project was again conducted by the CDFG from 1991 through 1993 to eliminate hybrid trout from within the range of Paiute cutthroat. This report presents a summary of events for the first two years of the Silver King Paiute Cutthroat Trout Restoration Project; a more thorough analysis is made of the third and final year of the project. (PDF contains 39 pages.)

Influence of chilled and frozen storage on the stability of trout and herring fillet

Effects of chilled and frozen storage on specific enthalpy (ΔH) and transition temperature (Td) of protein denaturation as well as on selected functional properties of muscle tissue of rainbow trout and herring were investigated. The Td of myosin shifted from 39 to 33 °C during chilling of trout post mortem, but was also influenced by pH. Toughening during frozen storage of trout fillet was characterized by an increased storage modulus of a gel made from the raw fillet. Differences between long term and short term frozen stored, cooked trout fillet were identified by a compression test and a consumer panel. These changes did not affect the Td and ΔH of heat denaturation during one year of frozen storage at –20 °C. In contrast the Td of two myosin peaks of herring shifted during frozen storage at –20 °C to a significant lower value and overlaid finally. Myosin was aggregated by hydrophobic protein-protein interactions. Both thermal properties of myosin and chemical composition were sample specific for wild herring, but were relative constant for farmed trout samples over one year. Determination of Td was very precise (standard deviation <2 %) at a low scanning rate (≤ 0.25 K·min-1) and is useful for monitoring the quality of chilled and frozen stored trout and herring.

Veränderungen der Farbe und thermischen Stabilität der Muskelproteine von Räucherforellen während der Kühllagerung

The aim of the investigation was to prove if different farming conditions like conventional and organical farming of rainbow trout may cause differences in quality which are detectable by physical methods such as colour measurement and differential scanning calorimetry. Colour measurement revealed remarkable differences in lightness. Smoked trouts originating from conventionally farmed fish were much lighter than those of organically farmed trouts. This difference in L* could already be found when colour measurements were taken on the raw material. However, during chilled storage differences were equalized. Redness and yellowness were not significantly influenced by farming and did not change remarkably during chill storage. Based on earlier investigations on changes in thermal stability caused by heating, DSC curves of smoked trout could be used to verify that the core temperature of smoked fish had reached at least 60 °C during hot smoking process. This temperature is demanded by the guidelines of the German Food Code. In the DSC curves only the actin peak was still visible. All other proteins were obviously denatured during the hot smoking. When DSC curves were taken from smoked trout after different durations of chilled storage it could be seen that the denaturation temperature of actin decreased almost linearly with progression of storage time.

Die Anwendung molekulargenetischer Verfahren in der fischereiwissenschaftlichen Forschung - Trennung von Fischpopulationen

The discrimination of stocks and separate reproductive units within fish species to facilitate fisheries management based on biological data has always been a challenge to fisheries biologists. We describe the use of three different molecular genetic techniques to detect genetic differences between stocks and closely related species. Direct sequencing of the mitochondrial ND3 gene describes the relationship between different aquaculture strains and natural populations of rainbow trout and revealed genetic homogeneity within the hatchery strains. Microsatellite analyses were used to explore the differences between redfish species from the genus Sebastes and to verify populations structure within S. mentella and S. marinus. This lead to an un equivocal discrimination of the species and an indication of populations structure within those species in the North Atlantic. The Amplified Fragment Length Polymorphisum (AFLP) methodology revealed genetic differences between Baltic and North Sea dap (Limanda limanda)and a possible population structure within the North Sea.

Einfluss von Reifung und technologischen Behandlungen auf die Proteine des Rogens von Regenbogenforellen (Oncorhynchus mykiss)

The use of differential scanning calorimetry for investigating the yolk proteins of the roe of rainbow trout allows to monitor the influence of maturation and vitellogenesis which modifies the DSC curves with regard to transition temperature and enthalpy. Two endothermic peaks become more and more pronounced with increasing maturation of the roe. However, it is still not known which protein fraction is represented by each of the peaks. DSC curves of yolk protein depend on fish species. They are also influenced by technological treatments. Further investigation is necessary to discover whether or not yolk proteins of other fish species are influenced in the same manner by maturation and vitellogenesis and which protein fraction represent the individual peaks.

Protecting a threatened coastal fish species through regional collaboration

Rainbow smelt (Osmerus mordax) are small anadromous fish that live in nearshore coastal waters during much of the year and migrate to tidal rivers to spawn during the spring. They are a key prey species in marine food webs, as they are consumed by larger organisms such as striped bass, bluefish, and seabirds. In addition, smelt are valued culturally and economically, as they support important recreational and commercial fisheries. The Atlantic Coast range of rainbow smelt has been contracting in recent decades. Historically, populations extended from the Delaware River to eastern Labrador and the Gulf of St. Lawrence (Buckley 1989). More recent observations indicate that rainbow smelt spawning populations have been extirpated south of Long Island Sound, and evidence of spawning activity is extremely limited between Long Island and Cape Cod, MA. In the Gulf of Maine region, spawning runs are still observed, but monitoring surveys as well as commercial and recreational catches indicate that these populations have also declined (e.g., Chase and Childs 2001). Many diverse factors could drive the recently noted declines in rainbow smelt populations, including spawning habitat conditions, fish health, marine environmental conditions, and fishing pressure. Few studies have assessed any of these potential threats or their joint implications. In 2004, the National Marine Fisheries Service (NMFS) listed rainbow smelt as a species of concern. Subsequently, the states of Maine, New Hampshire, and Massachusetts were awarded a grant through NMFS’s Proactive Conservation Program to gather new information on the status of rainbow smelt, identify factors that affect spawning populations, and develop a multi-state conservation program. This paper provides an overview of this collaborative project, highlighting key biological monitoring and threats assessment research that is being conducted throughout the Gulf of Maine. (PDF contains 4 pages)

Langcliffe hatchery investigations 1982 [on River Ribble near Settle]

Langcliffe hatchery investigations looks at fish mortalities for salmon (fry), sea trout, brown trout and rainbow trout, and explores the River Ribble's water supply.

Drawn to the Sea: Charles Bradford Hudson (1865-1939), Artist, Author, Army Officer, with Special Notice of His Work for the United States Fish Commission and Bureau of Fisheries

The biography of Charles Bradford Hudson that follows this preface had its seeds about 1965 when I (VGS) was casually examining the extensive files of original illustrations of fishes stored in the Division of Fishes, National Museum of Natural History, Smithsonian Institution. I happened upon the unpublished illustration of a rainbow trout by Hudson and was greatly impressed with its quality. The thought occurred to me then that the artist must have gone on to do more than just illustrate fishes. During the next 20 years I occasionally pawed through those files, which contained the work of numerous artists, who had worked from 1838 to the present. In 1985, I happened to discuss the files with my supervisor, who urged me to produce a museum exhibit of original fish illustrations. This I did, selecting 200 of the illustrations representing 21 artists, including, of course, Hudson. As part of the text for the exhibit, Drawn from the Sea, Art in the Service of Ichthyology, I prepared short biographies of each of the artists. The exhibit, with an available poster, was shown in the Museum for six months, and a reduced version was exhibited in U.S. and Canadian museums during the next 3 years.

Eden Fisheries Advisory Committee 14th January, 1975

This is the report from the Eden Fisheries Advisory Committee meeting, which was held on the 14th January, 1975. It covers information on the proposed regional fishing licence duties, and the report of the Working Party on future regional hatchery requirements, which includes sections on the future demands for migratory salmonids, brown and rainbow trout, and coarse fish plus the most effective means of meeting future demands. It also covers the Unit Fisheries Officer's report on fisheries activities. This section includes biological work undertaken on the Eden, information on the fishing of migratory fish, trout and coarse fish, hatchery work and prosecutions. 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 20th January, 1975

This is the report from the Lune, Wyre and Furness Fisheries Advisory Committee meeting, which was held on the 20th January, 1975. It covers information on the proposed regional fishing licence duties, and the report of the Working Party on future regional hatchery requirements, which includes sections on the future demands for migratory salmonids, brown and rainbow trout, and coarse fish plus the most effective means of meeting future demands. It also covers the Unit Fisheries Officer's report on fisheries activities. This section includes numbers on salmon and sea trout ova which were taken to Middleton hatchery. 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 Lancashire Fisheries Advisory Committee 22nd January, 1975

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 22nd January, 1975. It covers information on the proposed regional fishing licence duties, and the report of the Working Party on future regional hatchery requirements, which includes sections on the future demands for migratory salmonids, brown and rainbow trout, and coarse fish plus the most effective means of meeting future demands. It also covers the Unit Fisheries Officer's report on fisheries activities which looks at Langcliffe hatchery. 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.

Mersey & Weaver Fisheries Advisory Committee 27th January, 1975

This is the report from the Mersey and Weaver Fisheries Advisory Committee meeting, which was held on the 27th January, 1975. It covers information on the proposed regional fishing licence duties, and the report of the Working Party on future regional hatchery requirements, which includes sections on the future demands for migratory salmonids, brown and rainbow trout, and coarse fish plus the most effective means of meeting future demands. It also covers the report by the Unit Water Quality Officer on fisheries activities, which looks at fisheries management, stocking and biological work carried out on the River Bollin, Etherow and Goyt. Information on fish toxicity tests including methods and results are also included. 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 Lancashire Fisheries Advisory Committee 5th April, 1978

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 5th April, 1978. It covers information on fisheries income and expenditure, net licence duties and the concern over the growning population of the feral mink. It also includes the report by the area fisheries officer on river conditions and fishing, and migratory fish movements at Waddow Weir, Winckley Hall and Locks Weir. Included in this report is an update on Langcliffe hatchery, the stocking of brown trout and rainbow trout by the Water Authority and Angling Associations, and fish mortality and fish disease. 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.

Mersey & Weaver Fisheries Advisory Committee 12th April, 1978

This is the report from the Mersey and Weaver Fisheries Advisory Committee meeting, which was held on the 12th April, 1978. It covers information on fisheries income and expenditure, the pilot warm-water coarse fish hatching and rearing installation at Great Sankey, annual fishing permits on reservoirs and terminated angling leases. It also includes the report by the area fisheries officer on river conditions and fishing, and an update on Tintwistle hatchery and Worthington Stock Pools. Included in this report is also the stocking numbers of coarse fish, brown trout and rainbow trout by the Angling Associations, pollution incidents and fish mortalities and fisheries management. 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.

Mersey & Weaver Fisheries Advisory Committee 21st June, 1978

This is the report from the Mersey and Weaver Fisheries Advisory Committee meeting, which was held on the 21st June, 1978. It covers information on the monitoring of radioactivity in migratory fish, fishing offences and prosecutions and the income from sale of rod and line licences. It also includes the report by the area fisheries officer on river conditions and fishing, and an update on Tintwistle hatchery and Worthington Stock Pools. Included in this report is also the pollution incidents, fish mortalities, fisheries management and the stocking numbers of coarse fish, brown trout and rainbow trout by the Angling Associations. 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.